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BIOCHEMISTRY
by DUGGIN
Amino acids
10 essential AA (“PVT TIM HALL”)
-phenylanlanine
-valine
-tryptophan
-threonine
-isoleucine
-methionine
-histidine
-arginine
-leucine
-lysine
characteristics of AA
-ketogenic (can be synthesized to fats) AA  leucine and lysine
-aromatic (have a smell) AA  phenylalananine, tyrosine, tryptophan
-branched chain AA  valine, isoleucine, leucine
problem with breaking down branched chain AA
 Maple syrup urine disease
-sulfur containing AA  cysteine, cystine, methionine
foods that are deficient in AA
-limiting AA found in grains – lysine
-limiting AA found in legumes (soy, vegetables)  methionine
-limiting AA found in bean  tryptophan
Synthesis of cholesterol
acetyl CoA  HMG CoA  melvalonate  squalene  cholesterol
HMG CoA reductase – between HMG CoA and melvalonate
rate limiting enzyme for cholesterol bile
synthesis
rate limiting enzyme of glycolysis  phosphofructokinase (PFK)
rate limiting enzyme of fatty acid synthesis  acetyl CoA carboxylase
2
Glycolysis
glycolysis alone implies anaerobic
anaerobic glycolysis  conversion of glucose to lactic acid
net amount of ATP = 2
aerobic glycolysis  conversion of glucose to pyruvate
net amount of ATP = 36 (all other tissue) or 38 (liver)
depending on the tissue (including the link)
occurs in the cytoplasm
end products
2 ATP
2 NADH
2 pyruvate
complete breakdown is carbon dioxide and water
link between aerobic glycolysis and the Kreb cycle  enzyme pyruvate
dehydrogenase (converts pyruvate to acetyl CoA)
anaerobic and aerobic glycolysis occurs in the cytoplasm
the link is across the mitochondrial membrane
purpose of the electron transport system is to regenerate reducing power
NAD = reducing power (able to gain a H)
FAD = reducing power
lactate  pyruvate also a regenerating system producing NAD under
anaerobic conditions
calculation of ATP
2ATP
2NADH  transported by shuttle
2 pyruvate
cytoplasm
mitochondria
2 NAD+
pyruvate dehydrogenase
2 NADH
2 acetyl CoA
1 acetyl CoA  3 NADH
1 FADH2
1 GTP
each NADH  3 ATP
FADH2  2
GTP
1
7 ATP
since there are 2 acetyl CoA
NADH  6 x 3 ATP
FADH2  2 x 2
GTP
2x1
24 ATP  from the Kreb cycle
2 x 3  6  from link forming 2 NADH when pyruvate enters mito
2  from the anerobic cycle initially
32
3
shuttle transport  transports the 2 NADH formed into the mitochondria
in the liver  transports 2 NADH directly into NADH into the mito
without loss  32 + (2 NADH x 3) = 38 ATP total
NADH
cytoplasm
mitochondria
NADH
in other tissues  the NADH is converted into FADH2
32 + (2 FADH2 x 1) = 34 ATP total
NADH
cytoplasm
mitochondria
FADH2
Kreb cycle
is NOT anaerobic
the Kreb cycle and the electron transport system occurs inside the mitochondrial
production of NADH
1) isocitrate  isocitrate dehydrogenase  alpha-ketoglutarate
2) alpha-ketoglutarate  alpha-ketoglutarate dehyodrogenase 
succinyl CoA
3) malate  malate dehydrogenase  oxaloacetate
production of GTP
succinyl CoA  succinyl CoA synthetase  succinate
production of FADH2
succinate  succinate dehydrogenase  fumerate
Cori cycle
only involved with anaerobic process
takes place only between the liver and skeletal muscle
recycling system for glucose to lactic acid and back to glucose by
gluconeogenesis (also known as glycolysis in reverse – making glucose
from anything other than glucose)
1. Excess ammonia is transported from skeletal muscle to the liver by
*L-alanine
-transamination reactions  system which converts ketoacid to amino acid and
back but also AA  ketoacid overlapped at same time
-transamination reactions transfers nitrogen groups
pathway
pyruvate  alanine in skeletal muscle  alanine enters blood 
liver picks up alanine  alanine is converted into pyruvate and
release a nitrogen which enters the urea cycle
-vitamin B-6 necessary for transamination
-pyruvate is a ketoacid  alanine
4
-blood-urea-nitrogen bund
urea produced in the liver and excreted in the kidney
hidden in blood, urine, or cell
find where elevated and where sample came from
any liver problem will cause the bund to decrease – since liver can not
produce urea
any kidney problem will cause the bund to increase – since kidney is not
functioning to release urea
2. The molecule which enzmes act upon
*substrate – produce a product
enzyme kinetics
Km = affinity that an enzyme has for a substrate
Km = ½ Vmax
lower the Km the higher the affinity (inverse relationship)
ie. glucokinase and hexokinase
when glucose enter a cell, it is trapped by addition
of a phosphate
glucokinase (found only in liver) and hexokinase
(found in all other tissues) catalyze
glucose-6P
kinase at end of an enzyme – adds phosphate groups
Vmax = maximum velocity at which the enzyme will work
3. Which of the following is a product of pyruvate and can enter the TCA cycle
*acetyl CoA – enters the Kreb cycle
-dehydrogenase involved in oxidation or reduction reaction
-oxaloacetate will bind with acetyl CoA to form citrate
How many carbons are acetyl CoA – 4
4. Which of the following carbohydrates has RNA as its major component
*
O
HOH2C
OH
OH
OH
-ribose = 5C
-hexose = 6C
-deoxyribose (DNA) – 5C with one oxygen and hydrogen removed
The formation of deoxyribose is what type of reaction  reduction (gain of
hydrogen)
5
5. The monosaccharide in this structure is a/an
COOH
C=O
CHOH
CHOH
COOH
*ketopentose
-double bond O is on the first carbon  aldo
-double bond O is on the second carbon  keto
-name the first carbon according to the closest double bond
6. Which disease would occur if there was a deficiency in the enzyme necessary for the
conversion of phenylalanine to tyrosine
*phenylketonuria – deficiency of phenylalanine hydroxylase
-enzyme phenylalanine hydroxylase used
-catacholamine synthesis
phenylalanine  tyrosine (also make melanin) L-dopa  dopamine 
norepinephrine  epinephrine
phenylalanine  phenylalanine hydroxylase  tyrosine
deficiency of enzyme causes phenylketonuria
could lead to brain damage unless taken off phenylalanine
nutrasweet (aka aspartain) – contains phenylalanine
developed by Mensado (also developed genetically altered
foods)
first developed as a neurotoxin – always tired, can’t
concentrate
put in children’s vitamins (Flinstones)
one diet soda exceeds limit of methanol (wood alcohol)
toxicity levels
expiration put on diet soda due to deterioration of aspartain
to methanol
nutrasweet in temperature above 86 degrees will double the
dose for methanol toxicity
antidote for methanol is ethanol
tyrosin  tyosinase  melanin
deficiency of enzyme causes albinism
7. Pantothenic acid is necessary for the production of
*coenzyme A
-cobalamin = B12 (cyanocobalamin)
important element is cobalt
Cobalt is an element of which vitamin  B12
6
8. As the density of lipoproteins is increased ---- decreases and ---- increases
*triacylglycerol, protein
-increase in density  molecule gets heavier
-protein is heavy and an increase will cause increase in density
-VLDL molecule  transports indogenous fats (fats synthesized in the body)
from the liver to all the tissues
very low density lipoprotein – contains a lot of fat in it
-LDL molecule  transports cholesterol from the liver to the tissues (“leaves the
liver”)
low density lipoprotein
-HDL molecule  transports cholesterol from the tissues to the liver
high density lipoprotein
good cholesterol
get rid of excess cholesterol through feces
-chylomicrons  transport dietary fats
What transports fats from the colon to the liver  chylomicrons
dietary fats
-lipoprotein lipase
lipase  breaks down fats
VLDL, HDL, LDL
breaks down fats in lipoprotein (ie. triacylglycerol, triglycerol)  VLDL
 IDL (intermediate density lipoprotein)  LDL
9. Which of the following is responsible for carboxylation reactions
*biotin
What is found in decarboxylation reactions  B1 (thymine)
Which vitamin is involved in transamination reactions  B6 (pyridoxine)
“train” – B1, B2 B3
t = thymine
r = riboflavin
n = niacin
10. Which of the following is the active form of folate
*tetrahydrofolate
11. A DNA complementary strand would be which of the following: 5’-ATGCTACG-3’
*3’-TACGATGC-5’
-purines (“pure as gold”)
adenine
guanine
-pyrimidine (“king TUC”)
cytosine
thymine
uracil
7
-base pairs (“at the golf course”) in DNA
A-T
G–C
-strand of DNA is antiparallel
-base pairs in RNA
A–U
G-C
What is the complementary strand of RNA from the DNA strand: 3’ATGAC 5’
RNA – 5’ UACUG 3’
12. Which of the following is considered the most saturated
*coconut oil
-polyunsaturated fatty acid – corn oil, safflower oil, sunflower oil
linoleic acid  omega 6
canola and olive oil is good – high in monounsaturated fatty acid
margarine loaded in hydrogenated oils
13. Which of the following is lacking in a strict vegetarian diet
*B12 – cobalamine
-found predominently in animal products
14. Which of the following is an important adjunct in the absorption of glucose
*chromium  helps insulin function better
provides bridge between insulin & cell  increases glucose
tolerance
should be supplemented in diabetics
best form is chromium picolinate
toxic if too high concentration  should first do blood test to
determine glucose load
-insulin  polypeptide hormone
has a disulfide bond
-selenium  glucothione system needs this
-magnesium  goes hand in hand with calcium
-zinc  good for prostate
15. Which of the following is the best source of dietary vitamin C
*broccoli and fruits
-highest amount of vitamin C  brussel sprouts
-2nd  broccoli
-3rd  grapefruit
-glucose is highest in cereal and grains
-cancer patients  put on high protein diet  will starve cancer cell of glucose
8
16. Beta-oxidation occurs in the --- and is a --- process
*mitochondria, oxidative
“lysine the precusor to carnatine that funny little molecule carnatine, takes fatty
acid into the mitochondria for beta oxidation”
-fatty acid synthesis occur in the cytoplasm and is a reductive process
-the molecule that takes acetyl CoA out of the mitochondria into the cytoplasm
for fatty acid biosynthesis is citrate (one of the components of the Kreb
cycle)
17. Which of the following is fat soluble
*K – also D, E, A
18. Which of the following anemia is caused by a deficiency of vitamin B12
*pernicious  macrocytic hyperchromic anemia
could also cause megaloblastic anemia  2nd choice
Which of the following deficiency causes megaloblastic anemia (hyperchromic
macrocytic)  B9 (folic acid)
could also cause pernicious anemia  2nd choice
The most common microcytic hypochromic anemia  iron deficiency anemia
What is the most common microcytic hypochromic anemia in the Meditteranian
population  thalacemia
19. Which of the following reactions is responsible for forming deoxyribose from ribose
*reduction
20. Which metabolic process is coenzyme Q an integral part of
*electron transport chain
-oxygen is the terminal electron acceptor
21. Anaerobic glycolysis yields how many net ATP
*2
22. Ketones result from which of the following
*incomplete oxidation of fats
-3 ketone bodies
a) acetone – very toxic
b) acetoacetate – can be utilized for energy by the brain (primarily) and
heart
c) beta hydroxybuterate – can be utilized for energy by the brain
(primarily) and heart
23. Which of the following are pyrimidines
*uracil, cytosine
9
24. What type of bonds holds a single stand of DNA together
*phosphodiester
-hydrogen  alpha helix (secondary structures)
-peptide  protein
What holds two stands of DNA  hydrogen
What holds tertiary structure (ie myoglobin)  sulfur
25. Which of the following is the limiting AA in grains
*lysine
26. Which of the following is the function of ascorbic acid
*increase iron absorption
-ascorbic acid = vitamin C  involved in collagen formation
aids in the absorption of iron
-active form of iron is ferric (Fe2+) – but can not be absorbed
vitamin C converts ferric to ferrous (Fe3+)
ferrous goes back to ferric by copper
27. Malate is oxidized to which of the following
*oxaloacetate  NADH produced
How many steps are in the Kreb cycle  8 or 9 (9 best answer)
“Our Cousin Sicilia Isn’t Knowing So She Forgets Much”  steps of the Kreb
cycle
27. Which of the following provides nicotinamide
*tryptophan
pathway
tryptophan
niacin
serotonin
-only AA that is band off the shelf is tryptophan
-NAD  nicotinamide adenine dinucleotide
-FAD  flavin adenine dinucleotide  riboflavin (B2)
28. What is the charge of an AA when it is at its isoelectric point
*no charge, neutral
-Zwitter ion is an AA that is at its isoelectric point  balance (no negative and no
positive)
-characteristic of AA
-all AA are amphoteric compounds  can act as an acid or base depending on the
pH
29. A 100 kg adult requires approximately how many grams of dietary protein daily
*75
-for every 10 kg you need 8 grams of protein
10
30. Sucrose is broken down to --- and --*glucose, fructose
-glucose + glucose = maltose
-glucose + galactose = lactose
31. Which of the following is the most active form of vitamin D
*1, 25-dihydroxycholecalciferol
-peeling is the process the body utilizes to get rid of cancerous cells
-vitamin D eliminates cancer cells by forcing cells to mature  specifically
vitamin D3
-ergocalciferol  found in milk  from yeast
-sequence of making vitamin D
7-dehydrocholesterol in skin  cleaved by UV light  cholecalciferol 
goes to the liver to be hydroxylated (OH group added)  25hydroxycholecalciferol  goes to the kidney  converted to 1,25dihydroxycholecalciferol by enzyme 1-alpha-dihydroxylase (rate limiting
enzyme)
-when calcium levels drop  sensed by the parathyroid gland  release
parathyroid hormones
a) go to the bone  stimulate release of osteoclast  resorb
(break down) the bone  increase Ca and P in the blood (Ca
and P together forms bone so body gets rid of P)
b) activate 1-alpha-dihydroxylase in the kidney  formation of
active vitamin D  vitamin D will go to the gut  causes
formation of Ca binding protein will bind with phospherus 
absorbs Ca and P from the gut  increases Ca and P levels in
the blood
c) reabsorption of Ca by the kidney (at the proximal tubules) and
loss of P  Ca high in the blood and loss of P in the urine
d) calcitonin takes calcium out of the blood and returns to the
bone
-estrogen counteracts parathyroid hormone  when estrogen is present prevents
parathyroid hormone  DO NOT TAKE premerin and esterase synthetic forms  plant based or natural source is the best
-osteoporosis prevention is exercise (10 to 20 minutes a day, 3 times a week) 
-progesterone creams  prevents hot flashes  phytoprogesterone (plant form)
 from wild yams
-ovarian cancer is the worst form to get because it can not be detected until it has
metastasized
11
32. Which of the following is not part of an animal cell membrane
*insulin
-cholesterol makes the cell membrane fluid
-lecithin
Co Q10 helps to absorb lecithin to increase memory
-ginko baboba  increases blood flow to the brain  causes headaches due to
vasodilation
33. Alpha helices and beta pleated sheets are which type of structure
*secondary
What holds secondary structure  hydrogen
-primary structure  AA sequence
-tertiary structure  myoglobin
-quaternary structure  hemoglobin  2 alpha and 2 beta
34. What type of bond holds DNA bases together in a DNA double helix
*hydrogen
-ester = phosphodiester bonds
35. Which coenzyme is required for the reduction of a fatty acid chain during fatty acid
biosynthesis
*NADPH  comes from the hexose monophosphate shunt (aka pentose shunt,
phosphate shunt)
a) produces ribose sugars
b) produces NADPH or fatty acid biosynthesis
c) energy is not produced nor consumed
Where are fats made  in the cytoplasm
Where do you find NADH and FADH  Kreb cycle
-pyruvate dehydrogenae  takes pyruvate to acetyl CoA
36. What is the reducing agent in fatty acid biosynthesis
*NADPH
-reducing agent  will reduce a compound but becomes oxidized
NADPH (reducing agent – donates a hydrogen and becomes oxidized)
NADP (reduced form)
-oxidizing agent  will oxidize a compound and become reduced
37. Oxidation of a fatty acid yielding CO2 and H2O going through beta oxidation also
goes through which of the following
*Kreb cycle (TCA, citric acid cycle) and electron transport chain
-fatty acid broken down to acetyl CoA (by beta oxidation) which will enter the
Kreb cycle
-the complete break down of fat uses beta oxidation, Kreb cycle, electron
transport system
acetyl CoA carboxylase  rate limiting enzyme for fatty acid synthesis
-acetyl CoA ------------ malonyl CoA
-accumulation of malonyl CoA indicate fatty acid synthesis
12
38. Most cells can readily synthesize aspartate from
*oxaloacetate
-transamination reaction  oxaloacetate to aspartate
pyruvate to alanine
39. Which of the following is a branched chain AA
*leucine  also valine and isoleucine
What is not a derivative of tyrosine  serotonin (tryptophan is converted to
serotonin)
-things that end in –ine are derived from tyrosine usually
40. Which is the greatest source of pectin (soluble)
*fruits – especially skin
-pectin is soluble and good source of fiber
41. During starvation, triacylglycerols are broken down to fatty acids and glycerol in
adipose tissue. What is the ultimate fate of glycerol after transport to the liver
*glucose – precursor of glycerol
-triglycerol  3 fatty acid + glycerol
-glycerol is a source of glucose during starvation  gluconeogenesis
What is a supply of glucose  glycerol
42. Which lipoprotein is produced by the liver and transports tryglycerides to peripheral
tissues
*VLDL – transports endogenous fats  fats synthesized by the liver
-chylomicrons  transports dietary fats  fats absorbed from the GI system
43. By which mechanism do humans eliminate cholesterol
*via feces
44. Which of the following is a polypeptide hormone
*insulin – most important
45. Which types of bonds are between AA
*peptide
46. Which of the following is characteristic of a spontaneous reaction
*Gibbs free energy is negative
-Gibbs free energy – measures whether a reaction is energetically possible or not
positive  unfavorable and not spontaneous
negative  favorable and spontaneous
zero  no reaction  balanced
47. How many bases comprise a codon
*3
13
48. Acetyl CoA carboxylase catalyzes the conversion of acetyl CoA to
*malonyl CoA
49. Which compound is derived from pyruvate
*acetyl CoA
50. Purine nitrogen is derived form --- and is excreted as --*amino acids, uric acid
-only AA provide nitrogen
-purines broken down to uric acid
-increase in uric acid  gout
-urea is the break down product of proteins
51. tRNA is responsible for which of the following
*supplying AA during translation
52. Which of the following molecules is amphoteric
*aspartate
53. Which of the following glycosidic bonds is found in glycogen
*alpha 1,4  also contains alpha 1,6
-alpha 1,4 linkage is linear
-alpha 1,6 linkage produces branching
-beta 1,4 linkage in cellulose (insoluble) we can not break down
54. Which of the following depicts the activity of reverse transcriptase
*RNA to DNA
-DNA to RNA  transcription
-RNA to protein  translation
-DNA to DNA  replication
-RNA back to DNA  reverse transcription
55. Lack of B12 results in a deficiency of which of the following
*methionine
-B12 is necessary in the production of methionine
methionine  converted to homocysteine (demethylation reaction)
homocysteine to methionine  need B12 and B9 (folic acid) deficiency
will cause increase in methionine levels
-homocysteine is a vasoconstrictor and thus levels of homocysteine in the blood
will revealt heart disease
-homocysteine is converted to bile acids or bile salts by B6
56. Which AA is converted to indole in the intestine
*tryptophan
14
57. Which of the following carbon sources supplies the glycerol portion of triglycerides
for lipogenesis
*glucose
58. Which of the following is a four carbon glucose precursor
*fumerate  also malate
-pyruvate  3 C
59. Beta oxidatoin of fatty acids yields CO2 and H2O by using which of the following
metabolic processes
*TCA cycle and electron transport chain
-1 g of fat = 9 kcal
-1g of protein = 4 kcal
-1 g of carbohydrate = 4 kcal
-1 g of alcohol = 7 kcal
60. Which of the following is not a product of the pentose phosphate (hexose
monophosphate shunt) pathway
*ATP  no energy is consumed or produced in the pathway
-fructose-6-phosphate  is an intermediate of the pathway
-end result is the ribose sugar and the NADPH
61. Which of the following is a mucopolysaccharide (aka glycosaminoglycans)
*hyaluronic acid (in th synovial fluid)  also chonroitin sulfate
62. Which of the following distinguishes starch from cellulose
*starch is digestible by human enzymes and cellulose is not
63. The biosynthesis of cholesterol begins with which of the following
*acetyl CoA  beginning point of many of the pathways
64. The reductive steps in fatty acid biosynthesis requires which of the following
*NADH – coenzyme that is required
65. Which of the following is the final stage in the complete oxidation of fat
*TCA cycle
66. Which of the following is an intermediate in fatty acid biosynthesis
*malonyl CoA  accumulation means body is making fats
-rate limiting enzyme  acetyl CoA carboxylase
-carboxylation reaction  biotin present
67. Free radical are highly reactive species which result from the --- of lipids
*peroxidation
15
68. Which of the following are components of triglycerides
*fatty acids and glycerol
What kind of bonds are found in triglycerides  ester
alcohol + fatty acid = ester bond
69. Homocysteine is a product of the demethylation of
*methionine
-homocysteine  causes vasoconstriction
70. Which of the following is not an effect of the hydrogenation of vegetable oils
*lowered melting point
-trans fatty acid (free radical) destruction of essential fatty acids
71. To generate an unsaturated fatty acid, a saturated fatty acid must undergo
*oxidation
-saturation  a lot of H
72. Following the action of lipoprotein lipase, the very low density lipoprotein (VLDL)
remnant is converted into
*LDL
-VLDL  fats and cholestrol  broken to IDL by lipoprotein lipase  LDL in
the liver  LDL transports the cholestrol from the liver to the tissues
73. Cholesterol is not a component of which of the following foods
*peanuts  cholesterol is only found in animals
-ergosterol  plant version of cholesterol
74. Which of the following lipids comprise the majority of dietary fats
*triglycerides
75. Oxaloacetate is the alpha-keto analong of which of the following
*aspartic acid  transamination reaction
What is the B vitamin use in a transamination reaction  B6
76. The catabolism of heme results in the formation of
*bilirubin
-the accumulation of unconguated bilirubin in the basal ganglia of the brain 
Kernicteris
-unconjugated bilirubin is fat soluble
-conjugated bilirubin is water soluble
77. Which of the following do not contribute directly to the total AA pool of the body
*dietary nucleic acids  purines
78. Which of the following processes converts pryruvate to alanine
*transamination
16
79. Which nutrient forms the coenzyme involved in transamination reaction
*pyrioxidine – B6
-folic acid – B9
-retinol – A
-ascorbic acid – C
80. Which of the following is a catecholamine synthesized from tyrosine
*epinephrine
81. How many essential AA are aromatic
*2
-phenylalanine, tyrosine, tryptophan  but tyrosine is NOT essential
82. Thyroxine is derived from which of the following
*tyrosine  all thryoid hormones
83. Which enzyme catalyzes the conversion of UDP-galactose to UDP glucose
*epimerase
84. Which enzyme is presnet in the liver but not in the brain or muscle tissue
*glucose-6-phosphatase  only present in the liver
part of glycogenolysis  maintains glucose levels
during starvation
85. The quaternary structure of hemoglobin refers to which of the following
*association of alpha and beta subunits
86. Which of the following AA has the greatest positive net charge at the normal pH of
the blood
*lysine
-basic AA have the greatest positive net charge at your physiological pH
“HAL”  histadine, arginine, lysine
87. The daily protein allowance for a person weighing 80 Kg (176 lbs) is about
*64
-8g for every 10 kg
88. Which of the following is synthesized from panothenic acid
*Coenzyme A
-panothenic acid  B5
-a deficiency of panothenic acid  Burning foot syndrome  seen in old people
17
89. Which of the following vitamins is not a component of the pyruvate dehydrogenase
complex
*biotin  involved in carboxylation
-5 component  thyamine pyrophosphate
NAD
FAD
Coenzyme A
lipoic acid
-B1  decarboxylation reactions
18
1. Which fatty acids are synthesized by the body using acetyl CoA residues
*steric acid
-lenoleic acid  omega 6
-lenolenic acid  omega 3
-arachadonic acid
-steric acid  nonessential fatty acid  produced by the body
(essential fatty acid  NOT produced by the body)
2. Oxidative phosphorylation generates approximately --- percent of the ATP produced
from glycolysis, pyruvate dehydrogenase complex and the TCA cycle *90
-4 is substrate level phosphorylation  does NOT use electron transport system
succinyl CoA  succinate
glyceraldehyde 3-P  1,3-bis-phosphoglycerate
-32 is oxidative phosphorylation  oxidizing NADH to NAD to produce ATP
using the electron transport system  only occur in the mitochondria
3. Alpha-ketoglutarate is an intermediate in the --*tricarboxylic acid cycle (TCA)
4. In the following diagram of the tRNA molecule, which portion carries the AA
1  carries AA
4
2
3  anti-codon  recognizes the codon on mRNA
*1
-purpose of the tRNA is to transfer AA
-The transfer of an AA is known as which process  translation  RNA to
protein
citrate  oxaloacetate + acetyl CoA
CYTOPLASM
malonyl CoA
citrate 
oxaloacetate + acetyl CoA
MITOCHONDRIA
acetyl CoA  beginning of fatty acid synthesis
oxaloacetate + acetyl CoA  citrate
citrate leaves the mitochondria
citrate breaks down to oxaloacetate + acetyl CoA
acetyl CoA  malonyl CoA  fatty acid synthesis
oxaloacetate  recycled back into the mitochondria
19
-process
DNA to RNA  trans cription
RNA to protein  translation
mRNA contain the codon (made up of 3 nucleic acid)
tRNA contain the anticodon
5. A loss of lipoprotein lipase results in which of the following
*high chylomicron levels after a high fat meal
6. Which of the following is an intermediate in the formation of palmitic acid from
acetyl CoA
*malonyl CoA
-palmitic acid  fatty acid
-carnitine  takes fatty acid to the mitochondria for beta oxidation (fat
breakdown)
-precursor to carnitine is lycine
How do you get the carbons outside of the mitochondria and enter the cytoplasm
for fatty acid syntheisis  citrate(involved in fat synthesis)
-to determines whether the citrate goes through the Kreb or fatty acid synthesis
well fed
insulin levels increase
if levels of energy (ATP) is high citrate inhibits phosphofructose kinase
(negative feedback)
if energy needs satisfied and glycogen storage satisfied and excess glucose
remains, it is stored as fat
high citrate levels in the mitochondria then initiates fat synthesis
Where do fat synthesis occur  cytoplasm
7. What is the secondary messenger released in response to the hormone epinephrine
(aka adrenaline)
*cAMP
8. Which of the following is a sulfur containing AA
*cysteine
9. Which of the following is the starting material for endogenous cholesterol
biosynthesis
*acetyl CoA
10. Serotonin and niacin come from which of the following
*tryptophan
11. Which of the following elements binds to the phosphate group of ATP
*magnesium
-chromium use with insulin
20
12. A deficient essential AA creates --- nitrogen balance due to --- urea production and
excretion
*negative; increase  negative balance will mean more breakdown of proteins
and waste of urea)
-nitrogen balance  determined by intake vs excretion
if intake = excretion  zero
if intake > excretion  positive nitrogen balance
if intake < excretion  negative nitrogen balance
13. Dietary intake of 10 grams of protein provides approximately --*40
14. Which of the following sugars is a hexoketose
*fructose
15. Which of the following is the end product of anaerobic glycolysis in skeletal muscle
*lactate
-end product of aerobic glycolysis  pyruvate
16. Which of the following hormones contains sulfur
*insulin  polypeptide hormone with sulfur
has a disulfide bond
17. Which of the following is an endogenously produced carbohydrate polymer
comprised of repeating disaccharide units which contain glucosamide
*hyaluronic acid
-amylopectin and dextran  breakdown of carbohydrate
18. Which of the following is a major component of DNA
*
O
HOH2C
OH
OH
H
When you form a deoxyribose from ribose  reduction reaction
19. UDP-glucose is a major intermediate in the biosynthesis of
*glycogen
-UDP bound to glucose  making glycogen
UDP is a high energy compound  making glycogen (synthesis) costs
energy  provided by UDP  enzyme glycogen synthase
20. Linoleic acid is an essential fatty acid in humans due to the body’s inability to
synthesize which of the following
21
*omega 6
21. DNA synthesis is called
*replication  DNA to DNA
22. High levels of which of the following compounds inhibits cholesterol synthesis
*cholesterol  negative inhibitor  inhibits HMG CoA reductase
23. Which enzyme catalyzes the degradation of purines
*xanthine oxidase
-adenine and guanine  purines
-purines are broken down to uric acid
purine  hypoxanthine  xanthine  uric acid
rate limiting enzyme of purine metabolism  xantine oxidase
-gout is an accumulation of uric acid in the blood
24. Lactate dehydrogenase isoenzymes have the same
*type of coenzymes
-isoenzymes  have different enzymes with structure but have the same function
ie. lactate dehydrogenase
25. What type of reaction causes the formation of pyruvate and oxaloacetate from alanine
and aspartate, respectively
*transamination
26. Which of the following is a high energy compound
*glucose-6-phosphate  addition of P group causes it to be a high energy
compound
-UDP-glucose is the number one choice for high energy compound
27. Ornithine is an intermediate in which cycle
*urea cycle
-rate limiting enzyme  carbomoyl phosphate synthase
-nitrogen donor  glutamate
-occur in the cytosol and mitochondria
“ARCO”  arginine, citrulline, ornithine
28. Which of the following hormones inhibits fat mobilization
*insulin  biggest anabolic (synthesis) hormone in the body
-catabolic  breakdown  cortisol, glucagon, epinephrine
22
SAMPLE TEST
1. Which of the following does not make up the ninhydride reaction
*sulfuric acid
2. Which of the following are monosaccharides
*galactose, fructose, glucose
-maltose  glucose + glucose
-sucrose  glucose + fructose
-lactose  glucose + galactose
3. Which of the following is synthesized from the pentose phosphate shunt (aka hexose
phosphate shunt)
*NADPH and ribose
Where is carbon dioxide and glucose produced  TCA
4. Which of the following is the best source of pectin
*fruits and vegetables
5. In the first step of gluconeogenesis, by the process of ---- you convert pyruvate into
*carboxylation; oxaloacetate
-gluconeogenesis  reverse glycolysis
-oxaloacetate crosses the mitochondria as malate
6. What is the byproduct of the breakdown of muscle
*creatinine
7. Which vitamin is necessary for the conversion of alpha ketoglutarate to succinyl CoA
*niacin
-alpha ketoglutarate  succinyl CoA has production of NADH
8. What carries AA in protein synthesis
*tRNA
9. The compliment of 5’-AGTC-3’ is
*3’-TCAG-5’
10. NADH is a cofactor of which of the following
*dehydrogenase
-NADH (or NAD) and FADH (FAD)  all involved in oxidation/reduction
reactions  all are catalyzed by dehydrogenases
23
11. A proteolytic enzyme will most likely degrade a protein by which of the following
means
*hydrolysis  also breakdown of carbohydrates
12. Which of the following is a substrate for citrate synthase
*oxaloacetate
-oxaloacetate + acetyl CoA  citrate
13. Alpha-ketogluterate is an intermediate in which pathway
*tricarboxylic acid  aka Kreb cycle
-Embrden-Myerhoff  aka anaerobic
14. Which of the following steps in the glycolytic pathway is oxidative/ reductive
*glyceraldehyde-3-phosphate to 1,3-bisphosphate  where NADH is produced
and a dehydrogenase is used
15. The first chemical reaction in the catabolism of AA is
*deamination
What is the amino group converted to in the liver  urea  excreted in the
kidneys
16. In the aerobic catabolism of carbohydrates and lipids, what is the common product
*acetyl CoA
-aerobic breakdown of carbohydrate  pyruvate
-anaerobic breakdown of carbohydrate  lactate
17. A patient with galatosemia should not consume which of the following
*milk
18. Sucrose does not contain which of the following
*free anomeric carbon with OH groups
19. Degradation of which of the following produces glucose only
*amylose  homopolysaccharide of alpha-1,4-linkage of glucose
-raffinose  glucose + fructose + galactose  trisaccharide
20. Which of the following is the intermediate in the malate-aspartate shuttle
*oxaloacetate
21. Which of the following is a monosaccharide
*glucose
22. During fatty acid synthesis acetyl CoA is transported from the mitochondria to
cytoplasm as
*citrate
24
23. Ketone body synthesis takes place in which of the following tissues
*liver
-rate limiting enzyme of ketone body synthesis  HMG CoA synthetase
-ketone bodies (produced by the incomplete breakdown of fats)
acetoacetate
betahydroxybuterate
acetone
24. Which type of bond is found in RNA
*phosphodiester  aka covalent
25. Which of the following AA is a precursor to nicotinic acid
*tryptophan  niacin  nicotinamide
26. Which of the following is not an essential AA
*serine
“PVT TIM HALL”
27. Which of the following molecules transports AA to the site of protein synthesis
*tRNA
28. Which of the following nitrogenous bases is not found in DNA
*uracil
29. Oxaloacetate is an intermediate in which of the following cycles
*TCA
30. Which of the following is an essential aromatic AA
*tryptophan
-aromatic AA  phenylalanine, tryptophan, tryrosine  tyrosine NOT essential
31. In starvation, the carbon atoms in hepatic gluconeogenesis come from
*muscle protein
-gluconeogenesis  after glycogen stores in the liver have been all used up 
after glycogenolysis muscle proteins broken down
32. Disuse of which organ will directly impair the synthesis of urea
*liver  make here
33. Which of the following profoundly affects the utilization of carbohydrates
*insulin  anabolic  determines use of glucose
-glucagon  causes the breakdown of glycogen  early stages of starvation
34. Which of the following will block the effects of biotin
*avidin – present in egg whites
25
35. Coenzyme A is associated with which vitamin
*pantothenic  leads to the formation of coenzyme A
36. NADH is a coenzyme of which of the following
*dehydrogenase
37. Which of the following pairs are pyrimidines
*thymine;uracil
-pyrimids  pyrimidines
“KING TUC” – thymine, uracil, cytosine
38. The stop and start codon must be
*non-parallel and non-comparable
39. Glucagon and what other hormone have a similar effect upon the liver
*epinephrine
40. Chondroitin sulfate is a type of --- which is a commonly found in --*proteoglycans; connective tissue
-chrondroitin sulfate, hydroxyproline and hyaluronic acid are a proteoglycan
-cartilage is a connective tissue
41. Hydrolysis of amylopectin results in which of the following end products
*maltose  also isomaltose
42. Which of the following carbohydrates is a soluble dietary fiber
*pectinose
43. Which of the following is a Kreb’s cycle intermediate that occurs in the lowest
concentration
*oxaloacetate – in the lowest concentration and the most oxidized compound of
the Kreb cycle
44. Alpha amylase is found in which body secretion
*pancreas  also found in the mouth (saliva)
45. A genetic lack of fructose -1,6-bisphosphatase results in the inability to
*synthesize glucose from pyruvate
46. In a free system which of the following may stimulate an endergonic reaction (need to
add energy)
*increasing the temperature of the reaction
47. During aerobic glycolysis, one molecule of glucose is broken down to two molecules
of
*pyruvate
26
48. The process of synthesizing glucose from an AA is know as
*gluconeogenesis
49. The first step in the synthesis of glucose from pyruvate is the carboxylation of
pyruvate to form
*oxaloacetate  via pyruvate carboxylase
50. Which of the following is a Kreb’s cycle intermediate
*alpha-ketogluterate
51. Pyruvate is converted to which of the following prior to entering the tricarboxylic
acid cycle (TCA)
*acetyl CoA
52. Which of the following compounds is an intermediate in the synthesis of glucose
from pyruvate
*glyceraldehyde-3-phosphate
53. Which of the following is found in collagen
*proline  hydroxyproline
-collagen has hydroxyproline and lysine but primarily proline
54. The biosynthesis of FAD requires
*riboflavin
-pyridoxine  B6
55. Which of the following trace minerals is a component of the glucose tolerance factor
*chromium  needed for insulin function
56. The component of the electron transport system are located in which of the following
regions of a cell
*inner mitochondrial membrane
57. Which of the following is a component of the electron transport chain
*ubiquinone  aka CoQ10
58. Which of the following is an active form of folic acid
*tetrahydrofolate
-folic acid  B9
59. Which of the following minerals is a component of cytochrome B
*iron
27
60. The body converts beta-carotene to retinal by which of the following mechanisms
*oxidative lysis
-beta-carotene  2 molecules of retinal
does not work if already sick
vitamin A form would work better
61. Which of the following processes bioactivates thiamine and pyridoxine
*phosphorylation
62. The final stage in the formation of 1,25-dihydoxycholecalciferol occurs primarily in
the
*kidney
63. In the production of purine nucleotides the formal group was provided by
*B9 (folic acid)  needed in the synthesis of DNA and RNA (nucleotide)
64. Which of the following is synthesized by intestinal flora, becomes deficient due to
antibiotic therapy and is a coenzyme for carboxylation
*biotin
65. NADPH contains which of the following vitamins
*niacin
66. Which of the following vitamins is required for the hydroxylation of AA proline
*ascorbate  vitamin C  necessary for connective tissue and hyaline
67. Which vitamin is not valuable in preventing free radical damage in tissues
*cyanocobalamine
“ACES”  antioxidants of the body
-vitamin A  retinol
-vitamin C  ascorbic acid
-vitamin E  alpha-tocopherol
-selenium
68. The function of the nonsense codons include which of the following
*stop ribosome action in allowing for protein release
69. Which of the following is a form of iron that is most readily absorbed in the intestinal
tract
*ferrous
-most active form  ferric
70. Which of the following enzymes contain selenium
*glutathione peroxidase
28
71. Phytate and oxalate (basic acids  have negative charges) inhibit the absorption of
dietary
*calcium  bound to the phytate and oxalate
-most common type of kidney stones  oxalic acid
72. Which of the following is a primary end product of purine catabolism
*urate  salt of uric acid
-urea  end product of protein
73. Liver, dried fruit and molasses all contain
*iron
-also contained in rasin  dried fruits contain copper which convert iron to the
active form and able to absorb more efficiently
74. During the production of purine nucleotides, the formal group is provided by
*tetrahydrofolate
75. Which of the following promotes protein synthesis in humans
*methionine  known as the start codon
76. The complement base pairs of a DNA double helix are held together by bonds
*hydrogen
77. The DNA of an organism which contains 3% cytosine contains ---% thymine
*40
explaination
C = 3% given so G = 3% total is 6%
other 94% must be A and T combined so ½ of 94 = 47
78. Which of the following is mRNA guided protein synthesis
*translation
79. Transcription requires DNA template to produce
*RNA
80. Which of the following occurs in DNA, but not in RNA
*thymine
81. Which of the following is a keto sugar
*fructose  ketohexose sugar
82. Which of the following hormones promotes glycogen synthesis in the liver and
muscles
*insulin  anabolic  synthesis
29
83. Under resting conditions which of the following stimulates the synthesis of hepatic
glycogenic enzymes
*insulin
84. Epinephrine affects adipose tissue by promoting which of the following
*release of fatty acids
-epinephrine activates enzyme lipoprotein lipase to breakdown triglycerides to
release fatty acids
85. The process of fat metabolism in adipose tissue is initiated by high levels of
*epinephrine  causes breakdown of fats
86. Epinephrine is synthesized and secreted principally by the
*adrenal medulla
87. The biosynthesis of testosterone utilizes
*cholesterol
88. Which of the following hormones increases lipogenesis
*insulin
89. Which of the following is a pentose sugar
*ribose
-all monosaccharides are hexose sugars
90. A noncompetitive inhibitor of an allosteric enzyme affects which of the following
*Vmax only
-competitive inhibitor  increase the Km
91. Which of the following is a polysaccharide
*amylose
92. Which of the following is a hexose
*fructose
93. Which would be affected with low levels of thiamine
*Kreb’s cycle
-thiamine (B1)  involved in decarboxylation reaction
94. Which AA is both essential and aromatic
*phenylalanine
30
95. Which of the following is a branched chain AA
*valine
-branched chain AA
isoleucine
leucine
valine
96. Which of the following reactions provides most of the carbon atoms used to form
carbohydrates by gluconeogenesis during starvation
*hydrolysis of muscle breakdown
97. What makes up the color of the iris of the eye
*melanin
-rhodopsin  aka visual purple  allows you to see at night time
retinol (vitamin A) + opsin = binds to form rhodopsin at night
98. Myoglobin is considered to be
*a single polypeptide
-primary, secondary, tertiary  all single polypeptide chains
99. The formula for 2-deoxyribose is
*C5H10O4
-ribose  C5H10O5
100.
Which of the following is the beta-carbon
O
CH3 – (CH2)x – CH2 – CH2 – C – S – CoA
4
3
2
1
*C3
101.
Which of the following has a transfer methyl group
*methionine
-methionine to homocysteine  demethylation
102.
How many kilocalories are in 10 grams of fat
*90
103.
Which metabolic pathway does the follwing reaction occur in
glucose-1-posphate + UDP  UDP-glucose + Pi
*glycogenesis  whenever UDP is seen glycogen is being formed
104.
Alpha amylase is secreted from the
*pancreas
31
105.
What enzyme catalyzes an oxidation/ reduction reaction
*dehydrogenase
106. Beta-oxidation of an 18 carbon saturated fatty acid yields --- molecules of acetyl
CoA
*9 – divide the number of carbon by 2 (since acetyl CoA has 2 carbons)
107.
One gram of protein will give us how many kilocalories
*4
108.
Under fasting conditions, which of the following stimulates the synthesis of
hepatic gluconeogenic enzymes
*cortisol  causes gluconeogenesis during period of starvation
109.
Which of the following is found in DNA, but not in RNA
*thymine
110.
Which of the following does oxaloacetate become
*aspartate
32
TESTING
1. Which of the following is produced in the skin
*7-dehydrocholesterol
2. Which of the following AA is deficient in corn
*tryptophan and lysine
3. Which of the following is the most toxic fat soluble vitamin
*1,25 dihydrocholecalciferol  vitamin D
4. Which of the following AA is unnecessary if you have an ample amount of
nicotinamide
*tryptophan
5. Which of the following contains only purines
*guanine, hypoxanthine, uric acid
“History says All Girls are Pure”  hypoxanthine, adenine, guanine  purine
6. Which of the following enzymes transorms hypoxantine to uric acid
*xanthine oxidase
7. The symptoms of scurby are produced by
*hydroxyproline decrease  vitamin C needed for production of hydroxyproline
8. Which of the following is a nucleotide
*adenosine-5-monophosphate
What is the differenece between a nucleotide and a nucleoside
nucleotide  nitrogenous base, ribose sugar, phosphate group
nucleoside  nitrogenous base and ribose sugar
9. Which of the following substances transports fatty acids from the cytoplasm to the
mitochondria
*carnitine
10. What is the rate limiting enxyme of the pentose phosphate pathway
*glucose-6-phosphate dehydrogenase
-hexose monophosphae shune  produce NADPH, ribose sugars and the rate
limiting enzyme
11. Which of the following is derived from the pentose phosphate pathway
*ribose sugar
12. The pentose phosphate pathway provides --- for fatty acid synthesis
*NADPH
33
13. Lipoprotein lipase has the following responsibility
*breakdown triglycerides
14. During starvation glycerol can be converted to which of the following
*glucose
15. The breakdown of triglyerides is accomplished by which of the following
*hydrolysis
16. Which of the following is a cofactor in carboxylation reactions
*biotin
17. Which of the following is a cofactor in transamination reactions
*B6 – aka pyridoxine, pyridoxal phosphate
18. Which of the following vitamin deficiencies causes Beri Beri
*thiamine  common in alcoholics
19. Which of the following is a dehydrogenase reaction
*oxidation/ reduction
20. Which of the following has the most kilocalories per gram
*triglycerides
21. Which of the following is not part of the urea cycle
*citrate  Kreb cycle
“ArCO”  arginine, citrulline, ornithine
22. The charge of an AA is determined by which of the following
*pH
23. Acid and basic AA make a quartenary structure utilizing which of the following
bonds
*ionic
24. The most abundant substance in the cell membrane is
*phospholipids
-peptidoglycans  cell wall
25. Which of the following has the greatest protein density
*HDL  fats light and protein dense so high density lipoprotein
26. Which of the following foods has the highest concentration of cholesterol
*egg
34
27. Which of the following unsaturated fatty acids contains two carbon-carbon double
bonds
*linoleic
28. Which of the following coenzymes is responsible for converting methylmalonyl CoA
to succinyl CoA
*B12
-enzyme is methylmalonyl CoA mutase
29. Niacin and riboflavin are coenzymes involved in a --- reaction
*oxidation/ reduction
30. Hyperglycemia is closely associated with which of the following
*diabetes mellitus  low insulin (hypoinsulinism) causes hyperglycemia
-diabetes insipidus  deficiency of ADH
31. Which of the following is an essential fatty acid
*linoleic
32. Which of the following is a coenzyme derived from riboflavin
*FAD
33. Which of the following sugars make up sucrose
*glucose and fructose
34. Cholesterol is converted to --- by hepatic tissue
*bile salts
35. Which of the following is a ketohexose
*fructose
36. Which of the following is an intermediate in the formation of palmitic acid from
acetyl CoA
*malonyl CoA
37. Which of the following is not an antioxidant
*cholecalciferol
38. Which of the following is responsible for the transportation of iron in the blood
*transferrin
-ferritin  involved in storage of iron
“store your iron in a tin”
39. Hemoglobin contains which of the following
*4 binding sites to oxygen
35
40. A 6 carbon sugar can be converted to produce --- acetyl CoA
*2
41. In gluconeogenesis pyruvate is carboxylated to
*oxaloacetate
42. The purpose of thymine pyrophosphate in the pentose pathway is
*functions with transaldolase  also contains transketolase
43. Which of the following is an essential AA
*valine
44. Which of the following enzymatic activities is not in the pentose phosphate pathway
*glucose-6-phosphatase
45. Which of the following is found in gluconeogenesis, but not in glycolysis
*biotin  carboxylation reactions NOT present in glycolysis and TCA
-pantothenate  pantothenic acid
46. Niacin is derived form which of the following AA
*tryptophan
47. Which of the following only contains purine
*guanine  adenine
48. The substrate concentraton which gives ½ Vmax is
*Km
49. Which of the following characteristic of a competitive inhibitor
*increased Km
50. Which of the following is the function of tRNA
*sequence of the protein  polypeptide chain
tRNA
-contains anticodon
-recognizes the codon
-transfer of AA
51. DNA 5’-ACCG-3’ what is the DNA
*3’-TGGC-5’
52. Pleated sheets are considered to be
*secondary
36
53. Which of the following types of bonds are seen with pleated sheets
*hydrogen
54. Beta 1,4 bonds are found in which of the following
*lactose
55. In a substance that contains 30% starch, 10% maltose, 10% lactose and 50% sucrose,
how much is glucose, galactose and fructose
*70; 5; 35
-starch  all glucose
56. Which of the following is the intermediate in cholesterol synthesis
*HMG CoA
57. Which of the following has only two double bonded carbons
*linoleic
-double bonds
oleic  1 double bonded carbon
linoleic  2 double bonded carbons
linolenic  3 double bonded carbon
arachidonic  4 double bonded carbon
58. In the phenylalanine to tyrosine pathway, what is the product
*epinephrine
59. The primary function of the electron transport chain is to
*oxidize coenzymes and convert the energy to ATP  best answer
-regenerate reducing power  oxidation
60. If the electron transport chian is uncoupled, how would ATP production be affected
*decreased to 0
61. Which of the following is in aspartane
*phenylalanine
62. Zwitter ion is
*at its isoelectric point
63. Which of the following is a zymogen
*trypsinogen
-zymogen  inactive enzyme