Miscellaneous Questions from Old Tests

Question 1

Which of the following amino acids increase substantially in concentration in the blood during periods of vigorous exercise?

a) glutamate
b) alanine
c) glutamine
d) asp
e) orn

Answer 1

b) alanine

Question 2

Consider glucose which is enriched with 14C in position 3. The liver cell converts this glucose into acetyl-CoA and then to the fatty acid 16:0. Which of the carbons in this fatty acid will be enriched with 14C?

Answer 2

none of them! The tag ends up on the COO- group on pyruvate, which is lost when it is converted to acetyl-CoA

Question 3

Does NAD+ have a more negative (less positive) or a less negative (more positive) standard redox potential than cytochrome c?

Answer 3

Less negative (more positive).

In order for NADH to be able to transfer its electrons to Cytochrome C, it must be more negative. NAD+ has the opposite potential of NADH, and is thus more postive than Cytochrome C.

Question 4

What class of molecule is coenzyme Q?

Answer 4

A lipid

Question 5

The largest supply of available stored fuels in a ‘normal’ weight person (70 kg) is _______

Answer 5

fat in adipose cells

Question 6

T/F

One metabolic effect of insulin is that it decreases fatty acid synthesis in the liver

Answer 6

False

Question 7

Nutrients absorbed into the blood from the intestines are first sent via the circulatory system to the…

Answer 7

liver

Question 8

Which amino acid can be deamidated? arginine or glutamine?

Answer 8

Glutamine

Question 9

In the urea cycle, how many net ATP equivalents are consumed in the conversion of citrullene and aspartic acid into arginine and fumarate?

Answer 9

2

because asp + ATP –> AMP +PPi

ATP to AMP equivalent to using 2 ATP’s

Question 10

What class of enzyme is used to synthesize carbamoyl phosphate? synthase or synthetase?

Answer 10

synthetase

Question 11

Can gluconeogenesis take place in a muscle cell?

Answer 11

NO YA NINNY.

Question 12

In what subcellular location does the conversion of citrullene into arginino-succinate occur?

Answer 12

hepatocycle (liver cell) cytosol

Question 13

an increase in [acetyl-CoA] has what effect on the production of ketone bodies?

Answer 13

it activates it

Question 14

In B-oxidation there is a step where a carbon-carbon double bond is formed. To which component of the mitochondrial respiratory chain are these electrons first sent to?

Answer 14

Coenzyme Q

Question 15

Is the Krebs reaction that generates GTP a regulatory step under normal cellular conditions?

Answer 15

No

Question 16

Decarboxylation followed by reduction of the a-keto acid of alanine produces _________

Answer 16

ethanol

Question 17

In which subcellular location is ribulose 5 phosphate produced?

Answer 17

in the cytosol

Question 18

What is the key regulator in the determination of the flow through the oxidative branch of the pentose phosphate pathway?

a. ratio of [NADPH]/[NADP+]
b. ratio of [acetyl-CoA]/[CoA]
c. ratio of [acetyl-CoA]/[acetyl]
d. ratio of [NADH]/[NAD+]
e. ratio of [NAD+]/[NADH]

Answer 18

a. ratio of [NADPH]/[NADP+]

Question 19

In the synthesis of glycogen, to what end do you add the glucose units?

Answer 19

the reducing end

Question 20

What effect does a rise in the concentration of AMP have on gluconeogenesis?

Answer 20

It inhibits it

Question 21

In a mammal, does hexokinase or glucokinase have a lower Km for glucose?

Answer 21

hexokinase

Question 22

What is the redox state of the carbon in a carboxylic acid?

Answer 22

+3

Question 23

Consider the addition of water across a double bond. In this process, which carbon is reduced?

Answer 23

The one which receives the hydrogen

Question 24

What are you short in fatty acid catabolism when there is a double bond on an even or odd carbon?

Answer 24

double bond on an even carbon = short an FADH2

double bond on an odd carbon = consumes an NADPH

Question 25

Into what is propionyl-CoA converted in an odd-chain fatty acid?

Answer 25

Succinyl-CoA

Can be burned or used to make glucose