glycolysis and regulation

Question 1

completely reliant on glycolysis

Answer 1

red blood cells

Question 2

what cells oxidize glucose to pyruvate to generate ATP

Answer 2

all cells

Question 3

products of anaerobic glycolysis vs aerobic

Answer 3

lactate as opposed to TCA cycle participation

Question 4

LDH does what to produce lactate

Answer 4

NADH is oxidized to NAD+ in the cytosol which is used in a step to convert 1-glyceraldehyde-3P to 1,3BPG

Question 5

how is lactate removed from RBCs and exercising tissue?

Answer 5

Cori Cycle

Question 6

Cori cycle links

Answer 6

liver and muscle

Question 7

Describe the Cori Cycle

Answer 7

1. in RBC glucose goes through glycolysis to yield 2 lactate
2. 2 lactates are transferred to liver through blood
3. 2 lactate in liver reconverted to pyruvate by LDH then to glucose by gluconeogenesis

Question 8

what happens when you produce too much lactate?

Answer 8

lactic acidosis

Question 9

how do you get lactic acidosis and what are some causes

Answer 9

increased NADH/NAD+ ratio which prevents pyruvate from getting into TCA cycle and directs to lactate.
causes: excess alcohol, hypoxia, and TCA/ETC cycle issues

Question 10

glycolysis is a major pathway for oxidizing glucose and

Answer 10

metabolizing other dietary sugars, fructose and galactose

Question 11

ATP/ADP ratio is high are we going through glycolysis?

Answer 11

no

Question 12

ATP/ADP ration is low but concentration of AMP and ADP are. glycolysis rate will ___

Answer 12

increase

Question 13

hexokinase inhibited by ___

Answer 13

Glucose 6-phosphate

Question 14

PFK1 inhibited by ____ and activated by ___

Answer 14

- = ATP and citrate
\+ = AMP and F2,6-bisphosphate

Question 15

pyruvate kinase inhibited by ___ and activated by ____

Answer 15

- = ATP
\+ = F1,6-Bisphosphate

Question 16

Hexokinase vs Glucokinase Km

Answer 16

glucokinase high

hexokinase low

Question 17

Hexokinase vs Glucokinase affinity for glucose

Answer 17

glucokinase low

hexokinase high

Question 18

Glucokinase found in ____ while hexokinase found in ____

Answer 18

glucokinase: liver and pancreatic beta cells
hexokinase: all other cells

Question 19

Hexokinase vs Glucokinase Vmax

Answer 19

glucokinase higher

hexokinase lower

Question 20

Hexokinase vs Glucokinase induced by insulin?

Answer 20

glucokinase yes

hexokinase no

Question 21

Hexokinase vs Glucokinase feedback inhibited by glucose-6-P?

Answer 21

glucokinase no

hexokinase yes

Question 22

PFK1 is a tetramer and has 6 binding sites that are:

Answer 22

2 substrates: ATP and Fructose 6-P

4 allosteric modulators: inhibitors are ATP and citrate while activators are AMP and Fructose 2,6 bisphosphate

Question 23

what enzyme senses hormonal signaling by insulin and glucagon

Answer 23

PFK1

Question 24

how is PFK acting in muscle cells during activity?

Answer 24

AMP high, ATP low so glycolysis is promoted

Question 25

After a meal, insulin is high. what happens with PFK1, FBPase-2, and PFK2?

Answer 25

PFK2 is active generating F2,6BP which activates PFK1. glycolysis is stimulated

Question 26

In a fasting state. what happens with PFK1, FBPase-2, and PFK2?

Answer 26

FBPase-2 is active causing F2,6BP levels to fall which inactivates PFK1. glycolysis is inhibited

Question 27

pyruvate kinase allosteric activators and inhibitors

Answer 27

- = ATP
\+ = F1,6BP

Question 28

pyruvate kinase activation by F1,6BP is example of ____

Answer 28

feed forward activation

Question 29

When glucose is low, glucagon is ___, PKA is (active or inactive), liver PK gets phosphorylated, and is turned off. This is the switch to _____

Answer 29

high. active

gluconeogenesis

Question 30

reduced pyruvate kinase: glycolysis is inhibited, PEP enters _____

Answer 30

gluconeogenesis

Question 31

Fate of pyruvate: aerobic, fed conditions:

Answer 31

pyruvate to acetyl CoA or alanine

Question 32

Fate of pyruvate: anaerobic, fed condition:

Answer 32

pyruvate to lactate

Question 33

Fate of pyruvate: aerobic, fasting:

Answer 33

pyruvate to oxaloacetate

Question 34

what inhibits Glyceraldehyde 3-P dehydrogenase?

Answer 34

mercury and arsenate

Question 35

how does mercury inhibit Glyceraldehyde 3-P dehydrogenase?

Answer 35

inactivates the enzyme

Question 36

how does arsenate inhibit Glyceraldehyde 3-P dehydrogenase?

Answer 36

substitutes with inorganic P in the reaction and forms 1-arseno-3 phosphoglycerate which is an unstable molecule

Question 37

Pyruvate kinase adds phosphate to what molecule

Answer 37

ADP

Question 38

Partial lack of ____ or _____ activity depletes cells of ATP

Answer 38

pyruvate kinase

phosphoglycerate kinase

Question 39

Cells need ATP to

Answer 39

export electrolytes and to maintain proper osmotic balance between cytosol and extracellular compartment.

Question 40

No ATP leads to

Answer 40

swelling and destruction of RBCs which leads to hemolytic anemia

Question 41

Hereditary fructose intolerance is a defect in what enzyme

Answer 41

aldolase B

Question 42

Hereditary fructose intolerance causes

Answer 42

cellular phosphate to accumulate in Fructose 1-P form which depletes cell of inorganic P. inorganic P becomes too low for glyceraldehyde 3P dehydrogenase to function. ultimately, lack of aldolase B activity prevents liver cell from making ATP