Glycolysis

Question 1

Aerobic Glycolysis

Answer 1

O2 dependent, reoxidising NADH to NAD+ to generate ATP.

Question 2

Anerobic Glycolysis

Answer 2

O2 independent, producing ATP and NADH.

Question 3

How much ATP do the two types of glycolysis produce?

Answer 3

Anaerobic produces 2 ATP whilst Aerobic produces 32 ATP.

Question 4

Why is the final step of glycolysis is ATP produced?

Answer 4

As phosphoenolpyruvate is unstable, pyruvate kinase catalysed removal of its phosphoate group, forming two pyruvate.

Question 5

What is the fate of pyruvate determined by?

Answer 5

The cells microenvrionment; lacking mitochondria means energy demand increases to exceed rate that OP provides sufficient ATP, so LDH converts pyruvate into lactate.

Question 6

How is lactate utilised?

Answer 6

The conversion of pyruvate into lactate regenerates NAD+ from NADH, NAD+ being a cofactor necessary to maintain flow of glucose through glycolysis.

Question 7

What is the destiny of pyruvate?

Answer 7

Translocation intro mitochondria as a fuel input for CAC, driving ATP production of OP and other pathways

Question 8

Where does pyruvate derive from?

Answer 8

Glycolysis.

Question 9

What is pyruvate critical for?

Answer 9

Mitochondrial ATP generation, and driving various pathways that intersect the CAC.

Question 10

What are the three pathways generating Pyruvate?

Answer 10

Lactate oxidation, transamination of alanine and glycolysis.

Question 11

How is passage of pyruvate into the mitochondria mediated?

Answer 11

The Mitochondrial Pyruvate Complex on the inner and outer membranes.

Question 12

What two substrates are pyruvate converted into in the mitochondrial matrix?

Answer 12

Acetyl-COA or Oxaloacetate

Question 13

Oxaloacetate

Answer 13

A CAC intermediated reacting with Acetyl-COA to form citrate via citrate synthase.

Question 14

What is the function of oxaloacetate after conversion from pyruvate?

Answer 14

Entry into the CAC or conversion to phosphoenolpyruvate as a part of gluconeogenesis.

Question 15

What facilitates conversion of oxolacetate to phosphoenolpyruvate?

Answer 15

Phosphoenolpyruvate Carboxykinase

Question 16

What is the major cytosilic fate of pyruvate produced from PK?

Answer 16

Reversible reaction into lactate.

Question 17

What is a characertisitc of intense exercise?

Answer 17

Increased energy requirements for continued muscle contraction that exceeds mitochondrial capacity for ATP production by OP.

Question 18

How does the cell cope when energy requirements exceed mitochondrial ATP capacity?

Answer 18

Glycolytic ATP production is hindered when NAD+ levels diminish and NADH accumulates, as glycolysis required NAD+; so LDH supports glycolysis by NAD+ regeneration, where glycolysis supports energy demands quicker than OP can.

Question 19

What is the major form of ATP production during exercise for muscles?

Answer 19

Anaerobic glycolysis as oxygen is low and ATP is high.. opposed to the slower OP.

Question 20

What does LDH do in anaerobic glycolysis during exercise?

Answer 20

Oxidises pyruvate, coupled with NADH to yield NAD+ and lactate.

Question 21

What does lactate formed from LDH do?

Answer 21

It can be exported from the cell to liver for conversion to glucose, or convert back to pyruvate.

Question 22

What does LDH do to lactate in the liver?

Answer 22

LDH converts it back into pyruvate, so it can support glycolysis and gluconeogenesis in the Cori Cycle.

Question 23

The Cori Cycle.

Answer 23

Here, liver lactate is reconverted into pyruvate, and used gluconeogenesis, where resulting glucose resupplies energy-deficient muscle.

Question 24

How might lactate alternatively be supplied?

Answer 24

Alanine aminotransferase catabolises amino acids

Question 25

Cahill Cycle

Answer 25

A primary method of riddigng muscle tissue of ammonium ions, providing glucose to energy deprived muscles.