Energy Metabolism

Question 1

Meaning of Catabolism

Answer 1

Metabolic processes that break down big complex molecules into smaller molecules

Question 2

Meaning of Anabolism

Answer 2

Synthesis of big complex molecules from smaller ones

Question 3

What happens in glycolsis? (brief description)

Answer 3

Splitting of glucose (6C) to produce 2 pyruvate molecules (3C)

Question 4

Describe what happens in Glycolysis all the way until DHAP and GAP is made

Answer 4

1. Glucose is phosphorylated to make glucose 6 phosphate
   -hexokinase
   -ATP into ADP
   -irreversible step
2. Glucose 6 phoshate is phosphorylated to make fructose 6 phosphate
   -phosphate isomerase
   -ATP into ADP
3. Fructose 6 phosphate is phosphorylated to make fructose 1,6 bisphosphate
   -phosphofructokinase 1
   -ATP into ADP
   -rate-limiting step of glycolysis
4. Fructose 1,6 bisphosphate is cleaved to form dihydroxyacetone phosphate and glyceraldehyde 3 phosphate
   -aldose

Question 5

What happens when glucose tries to leave the cell after being phosphorylised?

Answer 5

Phosphorylated glucose can no longer exit the cell: helping to maintain the glucose gradient

Question 6

Why are two different products produced when Fructose 1,6-bisphosphate is cleaved?

Answer 6

This is because Fructose 1,6-bisphosphate is not symmetrical

Question 7

Triose phosphate Isomerase

Answer 7

Enzyme that converts dihydroxyacetone phosphate into glyceraldehyde 3-phosphate

Question 8

In detail describe what happens from GAP to the formation of pyruvate

Answer 8

1. Glyceraldehyde 3 phosphate is dehydrogenated and dephosphorylated to form phosphoenol pyruvate
   -NAD+, H+ into NADH
   -ADP, Pi into ATP

2.Phosphenol pyruvate is dephosphorylised to make pyruvate
-Pyruvate Kinase
-ADP, Pi into ATP

Question 9

What 3 things regulated enzymes catalysing irrevisible reactions?

Answer 9

Reversible binding of allosteric effectors

Covalent modification

Transcription

Question 10

The rate determining step in glycolysis is a …. regulated

Answer 10

major site

Question 11

Is AMP and H+ regulated negatively or positively in the liver?

Answer 11

H+ -negatively
AMP - positively