Lc. 8 (Alternative Pathways)

Question 1

Which of the following fermentation methods can occur in animal skeletal muscles?
a) lactic acid fermentation
b) alcohol fermentation
c) mixed acid fermentation
d) propionic fermentation

Answer 1

a) lactic acid fermentation

In animal skeletal muscles, when oxygen is limited (such as during intense exercise), lactic acid fermentation occurs. This process converts pyruvate into lactic acid

Question 2

Beta-oxidation is ________.
a) the breakdown of sugars
b) the assembly of sugars
c) the breakdown of fatty acids
d) the removal of amino groups from amino acids

Answer 2

c) the breakdown of fatty acids

Beta-oxidation is the process by which fatty acids are broken down in the mitochondria to produce acetyl-CoA

Question 3

The effect of high levels of ADP is to ________ in cellular respiration.
a) increase the activity of specific enzymes
b) decrease the activity of specific enzymes
c) have no effect on the activity of specific enzymes
d) slow down the pathway

Answer 3

a) increase the activity of specific enzymes

High levels of ADP signal that the cell needs more energy, so it activates enzymes in cellular respiration (like phosphofructokinase in glycolysis) to speed up the process and produce more ATP.

Question 4

Some prokaryotic organisms are strict anaerobes. For these organisms, even a trace amount of oxygen is toxic. Consider the three (or four) steps of aerobic cellular respiration. What step would be most problematic to strict anaerobes?

Answer 4

electron transport chain

Question 5

Glycolysis would proceed in an organism that cannot tolerate oxygen. (T/F)

Answer 5

True

Question 6

Up until now, we have largely considered the cellular respiration pathway in terms of glucose. However, many other cellular molecules contain energy.

Answer 6

Protein
Polysaccharide
Triglyceride
Amino acid
DNA

Question 7

Pick all that are true about the Citric Acid Cycle
a) The same molecule is the final product and the initial reactant of this pathway.
b) All energy from glucose is extracted by the end of this pathway.
c) This is a linear pathway
d) This is a circular pathway
e) Different molecules are the final products and the initial reactants of this pathway.

Answer 7

a) The same molecule is the final product and the initial reactant of this pathway.
b) All energy from glucose is extracted by the end of this pathway.
d) This is a circular pathway

Question 8

The effect of high levels of ADP is to ________.
a) have no effect on the activity of any enzymes in cellular respiration
b) decrease the activity of some of the enzymes in the cellular respiration pathway
c) increases the activity of all of the enzymes in the cellular respiration pathway
d) increase the activity of some of the enzymes in the cellular respiration pathway

Answer 8

d) increase the activity of some of the enzymes in the cellular respiration pathway

Question 9

Which part of cellular respiration is not controlled by regulating enzyme activity?

Answer 9

electron transport chain