Chapter 14 - Exam 3 Flashcards

1
Q

Glycolysis

A

process by which a molecule of glucose is degraded in a series of enzyme-catalyzed reactions to yield two molecules of the three-carbon compound pyruvate (some energy is conserved

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Preparatory Phase

A

ATP is consumed, delta G of the intermediates increases, hexose carbon chains are converted to glyceraldehyde 3-phosphate (phosphorylation of glucose and conversion to glyceraldehyde 3-phosphate)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Payoff Phase

A

yields (energy conserved as 2 ATP and 2 NADH) and 2 pyruvate (conversion of glyceraldehyde 3-phosphate to pyruvate and release of energy/storage in ATP and NADH)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Pathways for pyruvate after glycolysis.

A
  1. Under aerobic conditions, pyruvate is oxidized to acetyl-CoA
  2. Under anaerobic conditions, pyruvate is reduced to lactate or ethanol
  3. NADH must be recycled to regenerate NAD+
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Fermentation

A

processes that extract energy (as ATP) but do not consume oxygen or change the concentrations of NAD+ or NADH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Fermentation: Importance of oxidizing NADH

A

oxidizing NADH is important because its electrons are used to reduce pyruvate into lactate; lactate can then be recycle (converted to glucose during recovery)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Glucogenesis

A

pathway that converts pyruvate and related three and four-carbon compounds to glucose (mainly occurs in the liver in mammals)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

3 steps that are not the reverse of glycolysis (why?)

A

Steps 1, 3, and 10
Essentially irreversible because they have a large negative delta G

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Pentose Phosphate Pathway

A

pathway that oxidizes glucose 6-phosphate, producing pentose phosphates and NADPH (helps provide precursors for nucleotide and amino acid biosynthesis, reducing molecules for anabolism, and lessen oxidative stress)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What type of cells use pentose phosphate pathway?

A

-Rapidly dividing cells use ribose 5-phosphate to make RNA, DNA, and coenzymes
-Tissues that carry out extensive fatty acid synthesis (liver) require NADPH
-Tissues that actively synthesize cholesterol and steroid hormones (liver, gonads) require NADPH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly