1.8 Glycolysis Flashcards Preview

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Flashcards in 1.8 Glycolysis Deck (37):
0

Where does Glycolysis occur?

Cytoplasm

1

Glucose is oxidized to lactate under what conditions?

Anaerobic

2

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

True

3

Role of Liver with Glucose

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

4

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

Anaerobic

5

What do the GLUT transporters do?

Mediate movement of glucose from higher concentration to lower concentration

6

Which GLUT transporter is insulin dependent

GLUT 4

7

Where is GLUT 2 found

Liver, Kidney and B cells

8

Where is GLUT 1 found

Brain and RBC

9

What type of glucose transport tends to be insulin dependent

Facilitated transport

10

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

Na+ glucose symporter

11

What transports glucose out of intestinal cell and into blood?

GLUT 2

12

What happens when Glucose arrives in a cell

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

13

Why is Glucose 6-phosphate trapped in the cell

Phosphate esters of charged hydrophilic compounds do not penetrate membranes easily

14

What is the net reaction of Glycolysis

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

15

Anaerobic Glycolysis yields how many ATP

2 net ATP

16

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

3 (2.5)

17

Where is Anaerobic Glycolysis particularly important

Eye, Kidney medulla, Testes, leukocytes and RBC

18

What molecules activate Glycolysis

ADP, Pi, NAD+, Glucose

19

What three Key steps of Glycolysis help regulate the cycle

Hexokinase
Pyruvate Kinase
PFK 1

20

Muscle hexokinase has a low or high affinity for glucose

High, It has high demands of glucose

21

How is Hexokinase regulated?

Allosterically regulated by Glucose 6-Phosphate

22

Where is Glucokinase found?

In the liver

23

T or F, Glucokinase and Hexokinase are induced by Insulin

False, Insulin induces Glucokinase but does not induce Hexokinase

24

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

True

25

Which of Glucokinase or Hexokinase has a higher Km

Glucokinase has a high Km
Hexokinase has a low Km

26

What is the last step of Glycolysis

PEP to Pyruvate catalyzed by Pyruvate Kinase

27

What is the product of Pyruvate Kinase

ATP and Pyruvate

28

In what three ways is Pyruvate Kinase regulated

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

What 4 things Increase PFK 1 activity

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

30

What 2 things decrease PFK 1 acitivity

High ATP
High Citrate

31

T or F, Insulin activates PKF 2

True

32

What is the most significant regulator of PFK1?

Fructose 2,6-Phosphate

33

How does Glucagon affect Fructose 2,6 bisphosphate

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

34

How is Protein Kinase A related to Glycolysis

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

How does insulin affect F 2,6-bisphosphate

Increases

36

How does Glucagon affect F 2,6-Bisphosphate

It decreases in concentration