Carbohydrate Metabolism Glycolysis Connections

Front 1

When does glycolysis occur in RBC and brain?

Back 1

Both the fed and fasted states. All cells in the fed state

Front 2

Where does glycolysis occur?
Is it anaerobic or aerobic?

Back 2

Cytosol
anaerobic

Front 3

What are the net products of glycolysis?

Back 3

2 ATP and 2 NADH

Front 4

What are the starting materials for glycolysis?

Back 4

Glucose, NAD, ADP

Front 5

What is the first enzyme in the glycolytic pathway?

Back 5

Hexokinase and glucokinase (liver only)

Front 6

What enzyme is the site of main regulation of glycolysis?

Back 6

Phosphofructokinase PFK

Front 7

What rxtn does PFK catalyze?
Energy requirements?

Back 7

Fructose-6-Phosphate -> Fructose-1,6-Bisphosphate

Requires ATP

Front 8

Name the enzymes that require ATP in glycolysis?

Back 8

Hexokinase, PFK

Front 9

What rxn does Glyceraldehyde-3-phosphate dehydrogenase catalyze?

Back 9

Results in NADH production.

G-3-P->1,3-Bisphosphoglycerate BPG

Front 10

Glucose-6-phosphate is reversible, what enzyme does so and where located?

Back 10

Glucose 6 phosphatase and found only in the liver.

Front 11

What can be said about the respective Km values of hexokinase compared glucokinase?

Back 11

The affinity of glucokinase for glucose is much lower than that of Hexokinase. It has a very high affinity for glucose.

Front 12

So what role does glucokinase play in glucose storage?

Back 12

Since glucokinase only binds glucose when it is at high concentration this ensures that only fed state glucose is converted to glycogen or FA by the liver.

Front 13

Regulating allosteric factors of PFK?

Back 13

Activated: F-6-P substrate, AMP

Inhibited: ATP^

Front 14

What substrate results in Feed forward regulation of PFK?

Back 14

just a small amount of F-6-P increase, results in large increase in PFK rate

Front 15

Why does AMP activate PFK and not ADP?

Back 15

Because in cytosol all ADP is rapidly converted to AMP or ATP
Occurs exclusively in CYTOSOL via adenylate kinase

Front 16

Which steps of glycolysis produce NADH?

Back 16

Conversion of Glyceraldehyde-3-phosphate ->1,3 bisphosphoglycerate and pyruvate-> Acetyl CoA

Front 17

How is NAD supply maintained? two ways

Back 17

NADH transfers e* 1.to Malate-aspartate shutttle to form mt NADH 2.and by transfering to form mt FADH2 in the glycerol phosphate shuttle

Front 18

In aerobic conditions fate of pyruvate is?

Back 18

P-> Acetly CoA occurs in mt
Pyruvate Dehydrogenase PDH is mitochondrial enzyme

Front 19

Pyruvate-> Acetyl CoA yields what products? is it reversible?

Back 19

NADH formed and CO2 is realeased.

Acetly CoA can never be converted back to pyruvate.

Acetyl CoA may enter TCA to be oxidized

Front 20

Consequence of pyruvate>Acetly CoA rxn?

Back 20

Cannot be reversed and fatty acid carbon-oxidized to Acelty CoA- can never be made into glucose.

Front 21

PDH regulatory molecules?
How is PDH turned on/off?

Back 21

Activated: by all PDH substrates and ^ADP:ATP

Inhibited: by products except CO2

Phosphorylated/Dephosphorylated

Front 22

What is pyruvate fate under anaerobic?

Back 22

P> Lactate by lactate dehydrogenase

Front 23

What happens to lactate under aerobic and anaerobic condt.?

Back 23

Anaerobic- lactate moves through blood to aerobica cell where is converted by LDH (isozyme) back to pyruvate

Aerobic- fed state- either to TCA cycle or converted to FA in liver

Aerobic-fasted- returns to liver and converted to glucose via gluconeogenesis

Front 24

Name 5 connection of Glycolysis to anabolic processes?

Back 24

PPP
Glycogen
Triacylglycerol
2,3-BPG
FA Synthesis

Front 25

Pentose Phosphate Pathway Connected how?

Back 25

#2 Glucose-6-Phosphate-> Ribose-5-P via Pentose PP

Front 26

When does glycolysis occur in RBC and brain?

Back 26

Both the fed and fasted states. All cells in the fed state

Front 27

Where does glycolysis occur?
Is it anaerobic or aerobic?

Back 27

Cytosol
anaerobic

Front 28

What are the net products of glycolysis?

Back 28

2 ATP and 2 NADH

Front 29

What are the starting materials for glycolysis?

Back 29

Glucose, NAD, ADP

Front 30

What is the first enzyme in the glycolytic pathway?

Back 30

Hexokinase and glucokinase (liver only)

Front 31

How is glycolysis connected to glycogen?

Back 31

Glucose-1-P is intermediate between G-6-P and Glycogen. Glycogen>G-1-P>G-6-P

Front 32

How is glycolysis connected to Triacyglycerol production?

Back 32

Dihydroxyacetone-3-Phosphate DHAP-->Glycerol-3-Phosphate-------> +3FAcylCoa---> TRIACYLGLYCEROL

Front 33

How is glycolysis connected to 2,3-BPG production?

Back 33

1,3-Bisphosphoglycerate ---> 2,3-BPG

Front 34

How is glycolysis connected to FA syntheis?

Back 34

Pyruvate converted to Acetly CoA in the mitochondria. And combines with oxaloacetate (TCA intermediate) --> CITRATE which is then used in FA synthesis


Acetyl CoA + Oxalo

Front 35

What enzyme converts Pyruvate > Acetyl CoA? where

Back 35

Pyruvate Dehydrogenase in mt

Front 36

Pyruvate can be converted to?4 forms

Back 36

Acetyl CoA PDH
Lactate Lactate DH
Oxaloacetate PDecarboxylas
Alanine via transamination

Front 37

What rxn does pyruvate carboxylase catalyze? Cofactors req.? Location?

Back 37

Pyruvate(3C)>Oxalacetate4C

Biotin captures CO2 and uses ATP. Irrevers.
Mitochondria