Download First test material Study guide

Final exam study questions composite 2011 need 5 choices for the multiple choice Q
1. Which of the following is NOT a function of Lipids?
a- Source of energy storage
b- Major component of cell membranes
c- Precursors of all hormone production
d- Important in cell signaling
e- Hydrophobic molecules
Answer: C. Lipids are only precursors to steroid hormones and eiconasoids
Which of the following is correct concerning fatty acids?
a- sphingolipids contain both a serine and two fatty acid components
b- steroids have a 3 ring structure and are not highly soluble
c- Cholesterol is derived from steroids
d- Sphingosine is a component of gangliosides
e- Glycerophospholipids are based on glycine backbone
Answer: only A is correct.
Which of the following is NOT an important plasma membrane lipid?
a- Glycerolphospholipids
b- Cholesterol
c- Sphingomyelin
d- Glycocalyx
e- Triacylglycerol
Answer: E- triacylglycerols are storage form of fats, whereas the phospholipids, sphingosines are in
membranes;the glycocalyx is an important carbohydrate linked to proteins and lipids of the plasma membrane
that protects the cell against digestion and restricts uptake of hydrophobic compounds
Endocrine cell signaling:
a- only affects receptors immediately across the cleft of the secreting neuron
b- hormone from specific secreting cells enters blood stream and travels to targets
c- involve messengers that act on cells from which secreted, or same cell types
d- Acetylcholine is an example of this mechanism
e- Involves only tyrosine kinase surface receptor signaling
Answer: B… A and D defines paracrine signaling, C defines autocrine signaling.
Which of the following is the correct mechanism of a heptahelical receptor?
a- Receptor binds hormone  ATP dissociates the  subunit  binds target protein  RTK activated
b- Phosphorylation of the receptor occurs  GTP dissociates  subunit  binds target protein 
cAMP is produced
c- Phosphorylation of the receptor occurs  GTP dissociates  subunit  binds target protein  PIP3
is activated
d- Receptor binds hormone  GTP dissociates  subunit  binds target protein  cAMP is formed
e- Receptor binds hormone  GDP dissociates  subunit  binds target protein  cAMP is formed
Answer: D. GPCR are not phosphorylated, work through cAMP signaling pathway when  subunit binds
Briefly explain the bicarbonate buffer system as it pertains to the blood stream and a RBC
CO2 produced in cell respiration enters blood stream and is taken on by an RBC. Inside the RBC in the
presence of water and carbonic anhydrase to form carbonic acid which readily dissociates into H+ and
bicarbonate. H+ can be bound to hemoglobin or phosphate to be rid of by the body, while bicarbonate enters
the blood stream to buffer free H+ ions from metabolic acids.
Enzyme matching:
__b_Oxidoreductases
__c_Transferases
__d_Hydrolases
__f_Lyases
__e_Isomerases
__a_Ligases
a- Synthesize C-C, C-S, C-O, C-N
b- when electrons are transferred during a redox reaction
c- A functional Group is transferred from one molecule to another
d- Breaking C-O, C-N, or C-S Bonds using water
e- rearranging molecules
f-Breaks C-C, C-N or C-O bonds without using water or redox
Organelle and corresponding constituent matching
__e_Lysosomes
a- oxidation of long chain fatty acids
_c__Mitochondria
b- Synthesizes TAG, phospholipids
__a_Peroxisomes
c- Enzymes for fuel oxidation
__d_RER
d-Posttranslational modifications
__b_SER
e- cleave amide, ester and other bonds through the addition of H2O
Chemical messenger matching – choose as many as are relevant; choices may be used once, more than once, or
not at all.
__c_d___Immune system
A-retinoids B-catecholamines C-prostaglandins
__a_b_e__Endocrine system
D-polypeptides E- Neurohormones
__b_e___Nervous system
1. Which of the following are unique characteristics of erythrocyte cytoskeleton and membrane?
A. is composed of a 2D lattice of proteins that are linked to membrane proteins
B. is flexible and easily deformed to allow passage through capillaries
C. the plasma membrane is the only membrane of the red blood cell, which makes it ideal for
studying of membrane structure and function
D. contains glycolipids that signify blood group antigens
D. All the above
Answer – E. all the above
2. What is the equation for bicarbonate buffer system within the blood? Discuss the effects of H+ on the
ability for oxygen to bind to hemoglobin.
Answer – Within tissues, the release of CO2 causes H2CO3 in rbc, which releases H+, which causes O2 to be
released from hemoglobin and “replacing” it. In the lungs, this process is reversed. Because of the increase of
O2, O2 is able to bind to the hemoglobin and cause the release of H+. This in turn cause H2CO3 to form and
releases CO2 from the blood to be exhaled.
3. What nutrient is necessary for blood clot formation?
A. Vitamin K
B. Vitamin B
C. Glutamate
D. linoleic acid
E. vitamin B6
Answer – A. Vitamin K
4. Discuss how Warfarin prevents clotting. When would it be good to use warfarin to treat a patient?
Answer – Warfarin, also found in rat poison, is a vitamin K antagonist; it blocks vitamin K reductase that is
needed to regenerate vitamin K. Warfarin inhibits the actions of vitamin K-dependent carboxylase, an enzyme
that plays a role in the development of clotting factors. By resembling vitamin K, this drug prevents this enzyme
from forming vitamin K epoxide and gamma-carboxyglutamate on clotting factors VII, IX, X and proteins C and
S, which should bind Ca++ and play a large role in the coagulation cascade.
5. Where are steroid hormones synthesized?
A. Pituitary gland
B. Adrenal cortex and gonads
C. Hypothalamas
D. Liver
E. Adipose tissue
Answer – B. adrenal cortex and gonads
6. Discuss two ways that HMG-CoA is regulated. What treatment can be administered in order to reduce
the synthesis of cholesterol through inhibition of this enzyme?
Answer – (1) synthesis of HMG-CoA reductase is regulated at the level of transcription by SREBPs binding
SRE elements, (2) HMG-CoA reductase is regulated by proteolysis, and the enzyme is degraded in presence of
excess cholesterol, (3) HMG-CoA reductase is phosphorylated by an AMP-activated kinase to an inactive form,
and (4) the HMG-CoA reductas inactive form becoems actie when a phophatase removes the phosphate. Statins
can be used to reduce the synthesis of cholesterol as it inhibits the activity of HMG-CoA
1. Which of the following is not a classification of side chains of amino acids?
a. Nonpolar
b. Aromatic
c. Sulfur Containing
d. Acidic/Basic
e. None of the above
Answer is E; all of the choices are classifications
2. Which of the following is NOT a description of myoglobin?
a. Myoglobin evolved from gene duplication of the α chain, which in turn evolved from  chain
b. Myoglobin is an intracellular heme protein
c. Myoglobin contains four oxygen binding sites
d. Myglobin stores and transports O2 to the mitochondria
e. Myoglobin has a higher affinity for O2 at low concentrations (hyperbolic saturation curve)
Answer is C.
3. Describe how sickle cell hemoglobin is different from normal hemoglobin. How is it the same?
4. Describe primary, secondary, tertiary, and quaternary structure of a protein.
5. Define/Describe endocrine, paracrine, and autocrine reactions.
6. Enzymes function to:
a. Increase the rate of the reaction by decreasing the activation energy
b. Are used in the transition-state complex, enabling the reaction to proceed at a rapid rate
c. Decompose the substrate to produce the desired product
d. Stabilize the transition state of the reaction by electrostatic interactions or by forming a covalent
intermediate.
e. A and D
Answer is E
Which of the following enzymes in the TCA cycle is embedded in the inner mitochondrial membrane?
A. Isocitrate dehydrogenase
B. Succinate dehydrogenase
C. α-Ketoglutarate dehydrogenase
D. Citrate synthase
E. Acetyl CoA carboxylase
Answer : B. Succinate dehydrogenase
The TCA cycle is regulated within the mitochondria by with of the following:
A. Energy
B. Levels of NADH
C. Levels of FAD(2H)
D. All of the above
E. Both B and C
Answer: D. All of the above
Where are most of the TCA cycle enzymes located?
A. Inner mitochondrial membrane
B. Cytoplasm
C. Mitochondrial matrix
D. Intermembrane space of mitochondria
E. Nucleus
Answer: C. Mitochondrial matrix
Which of the following statements is incorrect about glycolysis?
A. Two molecules of ATP are used in the beginning of the pathway.
B. The reactions occur in the cytosol.
C. Phosphofructokinase-1 commits to glycolysis
D. Pyruvate kinase is the rate-limiting enzyme
E. The net result of glycolysis is 2 pyruvate, 2 ATP and 2 NADH.
Answer: D. Pyruvate kinase is the rate-limiting enzyme
Acyl-CoAs are transported into the mitochondria for -oxidation via which of the following?
A. Carnitine
B. Malonyl-CoA
C. NADH
D. Glucose
E. G protein receptors
Answer: A. Carnitine\
Which of the following is a cellular defense enzyme?
A. Superoxide dismutase
B. Catalase
C. Glutathione peroxidase
D. All of the above
E. Both A and B
Answer: D. All of the above
1. Metabolism of Cholesterol includes:
a. Its incorporated into membranes for stability
b. It serves as a precursor for bile salts
c. It is a precursor for steroid hormones
d. All of the above
e. Only a and c
Answer: D
2. Which of the following are properties of a lipid?
a. They are not soluble in water and would coalesce into droplets
b. Lipoproteins must transport lipids in blood
c. Large lipids cannot cross the cell membrane without a membrane receptor (steroid hormones do
cross the membrane without a receptor).
d. All of the above
e. Only a and b
Answer: D
3. Fatty Acids can be utilized/stored in which location(s)?:
a. Muscle
b. Brain
c. Adipose Tissue
d. Red Blood Cells
e. A and C
Answer E
4. What is the critical enzyme in conversion of carbohydrates to fatty acids via the Malonyl CoA pathway?
a. Acetyl CoA carboxylase
b. Hexokinase
c. HMG-CoA reductase
d. Lipoprotein lipase
e. Phospholipase C
Answer: A
5. Which one of the following organs has the highest demand for glucose as a fuel?
a. Brain
b. Muscle (skeletal)
c. Heart
d. Liver
e. Pancreas
Answer: A (but could also be the red blood cell if that were a choice)
What is the digestion process of triacylglycerols (occurs in the small intestine).
 Bile salts emulsify (do not change chemical composition), lipases digest.

Lipids (Fats) are absorbed through the microvilli. Short and medium FA absorb directly through
epithelium and enter the blood stream bound to serum albumin.
List some effects of Insulin. From where is insulin secreted? What are problems, symptoms of Diabetes I?
 Stimulates storage of glycogen in liver, muscle
 Stimulates synthesis of FA and triacylglycerols and storage in adipose tissue
 Stimulates synthesis in various tissues
 Release of insulin from beta cells suppresses secretion of glucagon from alpha cells
 Release of insulin occurs in a “fed state”
 Stimulates liver glycolysis
 Insulin is released from a beta-cell in the pancreas. Diabetes I results in deficiency of beta-cells, so no
insulin is being released. Therefore no glucose is being taken up in the cells; hyperglycemia.
What happens to the insulin and glucagon levels after a high carbohydrate meal? After two hours of having this
high-carbohydrate meal?
 Right after the meal (fed)
o There is a rapid increase of glucose in blood
o Increase of insulin
o Decrease of glucagon
 2 hours later (fasting)
o lower levels of insulin
o increased levels of glucagon
What are the two alternative routes of fatty acid oxidation? Give a brief overview of each and explain when
they may come in to use.
Answer:
1. Peroxisomal B-Oxidation of Fatty Acids
Very-long chain fatty acids (24-26 C) are oxidized exclusively in peroxisomes. This process is
very similar to mitochondrial B-oxidation and generates CoA and NADH. The peroxisomal membrane
contains the long-chain fatty acid acyl CoA synthetase. The first enzyme of peroxisomal oxidation does
not produce energy but instead produces hydrogen peroxide (H2O2), which is why this process is
confined to the peroxisome where H2O2 can be neutralized.
2. Peroxisomal a-Oxidation of Fatty Acids
Two branched-chain fatty acids, phytanic acid and pristanic acid, are oxidized in peroxisomes to
the level of a branched C8 fatty acid, which is then transferred to the mitochondria so that B-oxidation
may resume.
3. w-Oxidation of Fatty Acids
During this process fatty acids are oxidized at the w-carbon of the chain by enzymes in the
endoplasmic reticulum. The w-methyl group is oxidized to an alcohol and dehydrogenases then convert
the alcohol group to a carboxylic acid. The dicarboxylic acids produced by this process can then
undergo normal B-oxidation.
Both the peroxisomal oxidation and w-oxidation pathways are not feedback-regulated, instead
their rate is regulated by the availability of substrate. W-oxidation is normally a minor process but
produces dicarboxylic acids in increased amounts during conditions that interfere with B-oxidation,
such as carnitine deficiency or deficiency in an enzyme of B-oxidation.
Which two ketone bodies can acetoacetate produce?
a. B-hydroxybutyrate and acetone
b. Acetyl CoA and B-hydroxybutyrate
c. Palmitate and acetone
d. Succinate and propionyl CoA
e. Palmitate and Succinate
Answer: A
What does the radical nature of oxygen mean? Use diagram as well.
Answer: A radical is an unpaired electron and a free radical extracts electrons from
other molecules. The diagram to the right demonstrates how O2 behaves as a
biradical and the various reactive oxygen species that it forms.
Which of the following are reactive species that O2 is able to form?
a. O2b. H2O2
c. OH·
d. HOCl
e. All of the above
Answer: E.
1. Describe how sickle cell hemoglobin is different from normal hemoglobin. How is it the same?
2. Describe primary, secondary, tertiary, and quaternary structure of a protein.
3. Which of the following is a classification of side chains?
a. Nonpolar
b. Aromatic
c. Sulfur Containing
d. Acidic/Basic
e. All of the above
Answer E
4. Which of the following is NOT a description of myoglobin?
a. Myoglobin evolved from gene duplication of the α chain
b. Myoglobin is an intracellular heme protein
c. Myoglobin contains four oxygen binding sites
d. Myglobin stores and transports O2 to the mitochondria
e. None of the above is incorrect
Answer is c.
5. Enzymes function to:
a. Increase the rate of the reaction by decreasing the activation energy
b. Is used in the transition-state complex, enabling the reaction to proceed at a rapid rate
c. Only decompose a substrate to produce the desired product
d. Stabilize the transition state of the reaction by electrostatic interactions or by forming a covalent
intermediate.
e. A and D
Answer is E
1. Insulin is an anabolic hormone from:
A. Liver
B. - cells of pancreas
C. α cells of pancreas
D. chief cells of pancreas
E. anterior pituitary
Answer: B refer to 5th slide in notes of chapter 26
2. Insulin has which of the following functions:
A. Mobilizes fuels
B. Promotes growth
C. Maintains blood glucose in fasting
D. Promotes storage of fuels
E. Both B and D
Answer: E refer to 13th slide in notes of chapter 26
3. Which of the following are major regulators for glucagon release:
A. Cortisol
B. Epinephrine
C. Amino acids
D. Glucose
E. Both C and D
Answer: E refer to 18th slide in notes of chapter 26; aa are + regulators, glucose -regulator
4. Which enzymes digest lipids?
A. Lipases
B. Cholesterol esterase
C. Phospholipase
D. All of the above
E. None of the above
Answer: D refer to 9th slide in notes of chapters 32, 33
5. What are the fates of cholesterol:
A. Membranes
B. Cholesterol ester
C. Biliary Cholesterol
D. Bile acids
E. All of the above
Answer: E refer to 14th slide in notes of chapter 34
1. Describe the erythrocyte cytoskeleton
Answer: The cytoskeleton provides shape, structure, permits stretch. There are 2-D lattice of protein
links to membrane proteins, which include: spectrin (α, β), actin, ankyrin and band 4.1. Membrane
proteins found in the cytoskeleton include: glycophroin and band 3 proteins.
Refer to 15th slide in notes of chapter 44
How many moles of ATP are generated by the complete aerobic oxidation of 1 mol of glucose to 6 mol of CO2?
a)
b)
c)
d)
e)
46-48
40-42
36-38
30-32
26-28
Answer: c; assumes 3ATP/NADH; 2/FADH2.
Which of the following statements is true during a period of fasting/starvation?
a)
b)
c)
d)
e)
The liver synthesizes ketone bodies, and the liver and red blood cells use them as a fuel source
The liver synthesizes ketone bodies, and the brain and skeletal muscle use them as a fuel source.
The liver synthesizes ketone bodies, and the brain and red blood cells use them as a fuel source.
The brain synthesizes ketone bodies, and the liver uses them as a fuel source
The brain synthesizes ketone bodies, and the liver and the brain use them as a fuel source
Answer: b
Fill in the following sentence:
During Anaerobic Glycolysis, pyruvate is formed and converted to ____________ with the help of the enzyme
____________ , and ___________ is utilized in this conversion. This product can then be converted back to
pyruvate in the liver, heart, or skeletal muscle, or converted to glucose in the liver for use by red blood cells
(Cori cycle).
a) Glucose; pyruvate esterase; GTP
b) Glucose; lactate dehydrogenase; GTP
c) Glucose; pyruvate decarboxylase; NADH
d) Lactate; pyruvate decarboxylase; NADH
e) Lactate; lactate dehydrogenase; NADH
Answer: e
Due to the fact that the TCA is a _________ cycle, ___________ reactions are necessary to replenish some of
the intermediates which may be lost or pulled out.
a) Open; anaplerotic
b) Closed; cataplerotic
c) Open; cataplerotic
d) fast; anaplerotic
e) slow; cataplerotic
Answer: a
Which of the following complexes of the ETC is the energy generating complex?
a) Complex I (NADH dehydrogenase)
b) Complex II
c) Complex III (cytochrome b-c)
d) Complex IV (cytochrome oxidase)
e) Synthase Complex
Answer: e
In the ETC a concentration gradient is created by pumping H’s from the ____________ to the _____________;
and ATP is generated by pumping H’s from the _____________ to _____________.
a)
b)
c)
d)
e)
Intermembrane space, mitochondrial matrix; intermembrane space, mitochondrial matrix
Mitochondrial matrix, intermembrane space; mitochondrial matrix, intermembrane space
Mitochondrial matrix, intermembrane space; intermembrane space, mitochondrial matrix
Intermembrane space, mitochondrial matrix; mitochondrial matrix, intermembrane space
None of the above is correct, electrons are pumped across the membranes, not H.
Answer: c
Which of the following is considered a reactive oxygen species, or can be dangerous to the body?
A: superoxide anion (O2-)
B: oxygen (02)
C: hydrogen peroxide (H2O2)
D: hydroxyl radical (OH∙)
E: hypochlorous acid (HOCl)
F: nitric oxide (NO)
a) All of the above
b) None of the above
c) 3 of the above
d) 4 of the above
e) 5 of the above
Answer: e
1 NADH is the equivalent of how many ATP? 1 NADH = 3 ATP
1 FAD2H is the equivalent of how many ATP? 1 FADH2 = 2 ATP
1 GTP is the equivalent of how many ATP? 1 GTP = 1 ATP
How many ATP are generated from 2 molecules of palmitate (16 C) through the beta-oxidation pathway?
(include the ATP generated from acetyl CoA being completely oxidized through the ETC chain) 258
Where does TCA take place? Mitohchondrial matrix
Where does the ETC carry out its functions? The inner mitochondrial membrane
Where in the cell does glycolysis take place? Cytoplasm of the cell
What generates more energy, aerobic or anaerobic glycolysis? Aerobic glycolysis