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CHEM 125
Test 4-A
Dupre
Fall 2003
Name:
SSN:
Multiple Choice (60 points total; 3 pts. each). Choose the correct answer for each of the
following questions. Write the letter clearly in the blank next to the number.
1.
a.
b.
c.
d.
Which of the following sugars would not five a positive result to a Tollens test
Glucose
Fructose
Deoxyribose
Ribose
2.
a.
b.
c.
d.
Lactose is made up of which of the two following sugars
Glucose and Galactose
Fructose and Galactose
Maltose and Glucose
Sucrose and Fructose
3.
Which of the following disaccharides is -maltose with an -glycosidic linkage
a.
b.
CH 2 OH
O
OH
HO
CH 2 OH
O
HO
O
HO
OH
CH 2 OH
O
HO
O
OH
HO
OH
d.
CH 2 OH
O
OH
4.
a.
b.
c.
d.
HO
OH
c.
HO
CH 2 OH
O
OH
OH
CH 2 OH
OHO
HO
O
OH
CH 2 OH
O
OH
HO
CH 2 OH
OHO
HO
O
OH
The most common carbohydrate source we consume is:
sucrose
starch
glycogen
cellulose
OH
5.
a.
b.
c.
d.
Soaps work by trapping fat and oil inside particles known as
lipoproteins
bilayers
bubbles
micelles
6.
a.
b.
c.
d.
Bile salts are necessary to aid your body in the processing of :
proteins
carbohydrates
fats
starches
7.
a.
b.
c.
d.
What type of bonding is formed between two amino acids in a polypeptide chain
ester
ketal
acetal
amide
8.
Which of the following protein characteristics can be described as a secondary
structural element?
order of amino acids
beta sheet
3D folding
number of amino acids
a.
b.
c.
d.
9.
Polypeptide chains that are responsible for the catalysis of biological reactions are
referred to as:
a.
proteins
b.
cofactors
c.
enzymes
d.
substrates
10.
a.
b.
c.
d.
Which of the following nitrogenous bases is a purine derivative?
adenine
uracil
thymine
cytosine
11.
a.
b.
c.
d.
The structural components of a nucleotide are:
nitrogenous base and phosphate ester
phosphate ester and cyclic sugar
nucleoside, cyclic sugar, and a nitrogenous base
nitrogenous base, phosphate ester, and cyclic sugar
12.
a.
b.
c.
d.
What kind of process is glucogenesis?
anabolic
catabolic
oxidation
hydrolysis
13.
Carbohydrates, lipids, and proteins are all converted into ___________ before
entering the Krebs cycle.
acetate
acetyl-CoA
coenzyme A
pyruvate
a.
b.
c.
d.
14.
a.
b.
c.
d.
15.
a.
b.
c.
d.
16.
a.
b.
c.
d.
17.
a.
b.
c.
d.
During digestion, carbohydrates are converted into three simple sugars before
absorption into the blood stream. Which of the following is not one of those
simple sugars?
mannose
fructose
glucose
galactose
Which of the following statements concerning metabolism of proteins is true:
proteins are stored in the pancreas for later use
proteins can be removed from the diet with almost no adverse effects
proteins are broken down into amino acids, which circulate in the body’s amino
acid pool for use in building tissue
the smallest unit of a protein is a peptide, which is absorbed into the blood stream
in the small intestine
How many new carbon atoms are introduced into the Krebs cycle with the
introduction of 1 acetyl-CoA molecule?
2
3
1
4
What is the name of the condition caused by the absence of carbohydrates in the
diet, which leads to the production of an excess amount of acetyl-CoA.
heart disease
ketosis
point mutation
basosis
18.
a.
b.
c.
d.
Excess carbohydrates are stored as ________________ in ________________.
glycogen, the liver
glucose, the bloodstream
peptides, the pancreas
glycogen, the adipose tissue
19.
a.
b.
c.
d.
Which of the following choices will produce the most ATP when completely
metabolized?
1 mole of glucose
1 mole of amino acid
1 mole of fatty acid
1 mole of triglyceride
20.
a.
b.
c.
d.
The products of glycolysis proceeds through which order?
six-membered cylclic sugar, pyruvate, acetate
six-membered cyclic sugar, five-membered cyclic sugar, pyruvate
six-membered cyclic sugar, acetyl-CoA, pyruvate
five-membered cyclic sugar, six-membered cyclic sugar, ketone body
Short answer (40 points total) Provide the correct answer to each of the following questions in
the space provided or in the appropriate blank. For three bonus points, please write the
straight-chain structure of any monosaccharide we discussed on back of the first page of
this test. Partial credit will be awarded, so show all of your work!
1.
The names of the three major products of the Krebs cycle are (3 pts each):
1)
2)
3)
2.
From the above question, how many ATP molecules are produced from 1 molecule of
each major product? (3pts each)
1)
2)
3)
3.
The fatty acid below can be split up into acetyl-CoA by a process called β-oxidation.
Draw lines through the C-C bonds where the acid will be split. Indicate how many acetylCoA molecules will be produced by 1 molecule of this fatty acid. (4 pts)
CH3-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-COOH (Lauric acid)
4.
Step 8 of the Krebs cycle is the oxidation of malate. What do you predict the structure of
the products will be? (4 pts)
COOHO
C
H
+
NAD
+
CH2
COO-
5.
Fill in the blanks with the correct answers concerning the Krebs cycle (1 pt. each)
6.
How many oxidation/decarboxylation reactions occur in the Krebs
cycle?_________
b.
How many hydration reactions occur in the Krebs cycle?_____________
The following three amino acids will bond to create a peptide. Draw the appropriate
peptide. Label the three amino acids as polar, non-polar, acidic, or basic. (5 pts)
Valine
Threonine
H
O
H
O
C
C
C
C
H3C
CH
H3C
a.
H3 N
+
HO
CH
O-
H3C
H3 N
+
Lysine
O-
H3 N
+
H
O
CH2 CH2 CH2 CH2 C
C
H3N
+
O-
7.
The following fragment of a DNA strand is used in RNA transcription to produce a
peptide. Show both the mRNA chain produced from this DNA chain, and the peptide this
codes for using the chart on the following page. (3 pts.)
5’ GACTTAACGCATCCT 3’
8.
Below is drawn the structures of four nitrogenous bases attached to a backbone chain.
Choose two complimentary bases and show how hydrogen bonding holds them together
(3 pts).
H3C
O
C
H
C
C
N
CH2
H
THYMINE
C
N
C
N
H
CH2
O
to Chain
H
C
N
C
H
H
H
O
H
C
N
N
C
C
C
N
H
N
H
N
to Chain
C
C
C
N
N
N
N
to Chain
H
to Chain
CYTOSINE
C
N
CH
CH
C
O
H
N
ADENINE
GUANINE