1.8 Glycolysis Flashcards Preview

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Flashcards in 1.8 Glycolysis Deck (37)
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0
Q

Glucose is oxidized to lactate under what conditions?

A

Anaerobic

1
Q

Where does Glycolysis occur?

A

Cytoplasm

2
Q

T or F, Glycolysis is Ubiquitous - Found in all living cells

A

True

3
Q

Role of Liver with Glucose

A

To serve as a pathway by which excess glucose can be ultimately converted to fat for storage

4
Q

All of the ATP of the RBC is derived from what type of glycolysis

A

Anaerobic

5
Q

What do the GLUT transporters do?

A

Mediate movement of glucose from higher concentration to lower concentration

6
Q

Which GLUT transporter is insulin dependent

A

GLUT 4

7
Q

Where is GLUT 2 found

A

Liver, Kidney and B cells

8
Q

Where is GLUT 1 found

A

Brain and RBC

9
Q

What type of glucose transport tends to be insulin dependent

A

Facilitated transport

10
Q

Cotransport of glucose into the intestinal cell is mediated by what?

A

Na+ glucose symporter

11
Q

What transports glucose out of intestinal cell and into blood?

A

GLUT 2

12
Q

What happens when Glucose arrives in a cell

A

It is trapped in the cell by be converted to Glucose 6-phosphate. This reaction requires ATP and is first step of glycolysis

13
Q

Why is Glucose 6-phosphate trapped in the cell

A

Phosphate esters of charged hydrophilic compounds do not penetrate membranes easily

14
Q

What is the net reaction of Glycolysis

A

Glucose –> 2 pyruvate
2 ADP –> 2 ATP
2 NAD+ –> 2 NADH

15
Q

Anaerobic Glycolysis yields how many ATP

A

2 net ATP

16
Q

Under aerobic conditions NADH can be oxidized in Electron Transport Chain to make how many ATP

A

3 (2.5)

17
Q

Where is Anaerobic Glycolysis particularly important

A

Eye, Kidney medulla, Testes, leukocytes and RBC

18
Q

What molecules activate Glycolysis

A

ADP, Pi, NAD+, Glucose

19
Q

What three Key steps of Glycolysis help regulate the cycle

A

Hexokinase
Pyruvate Kinase
PFK 1

20
Q

Muscle hexokinase has a low or high affinity for glucose

A

High, It has high demands of glucose

21
Q

How is Hexokinase regulated?

A

Allosterically regulated by Glucose 6-Phosphate

22
Q

Where is Glucokinase found?

A

In the liver

23
Q

T or F, Glucokinase and Hexokinase are induced by Insulin

A

False, Insulin induces Glucokinase but does not induce Hexokinase

24
Q

T or F, G-6-P inhibits Hexokinase but does not inhibit Glucokinase

A

True

25
Q

Which of Glucokinase or Hexokinase has a higher Km

A

Glucokinase has a high Km

Hexokinase has a low Km

26
Q

What is the last step of Glycolysis

A

PEP to Pyruvate catalyzed by Pyruvate Kinase

27
Q

What is the product of Pyruvate Kinase

A

ATP and Pyruvate

28
Q

In what three ways is Pyruvate Kinase regulated

A
  1. Covalent Modification
  2. High ATP inhibits Pyruvate Kinase by decreasing its affinity for PEP
  3. Inhibited by Acetyl CoA, Alanine and Long Chain FA
29
Q

What 4 things Increase PFK 1 activity

A

High F 6-P
High ADP
High AMP
High F 2,6-P

30
Q

What 2 things decrease PFK 1 acitivity

A

High ATP

High Citrate

31
Q

T or F, Insulin activates PKF 2

A

True

32
Q

What is the most significant regulator of PFK1?

A

Fructose 2,6-Phosphate

33
Q

How does Glucagon affect Fructose 2,6 bisphosphate

A

It declines in activity which in turn inhibits PFK 1 and slows glycolysis

34
Q

How is Protein Kinase A related to Glycolysis

A

High Insulin Decreases levels of active PKA
Decreased PKA activity favors Dephosphorylation of PFK-2 (activation)
Activated PFK-2 increases concentration of F 2,6-Bisphosphate
F 2,6-Bisphosphate activates PFK-1 and Glycolysis

35
Q

How does insulin affect F 2,6-bisphosphate

A

Increases

36
Q

How does Glucagon affect F 2,6-Bisphosphate

A

It decreases in concentration