Glucose as fuel 2

Question 1

How can the pathway of glycosylis be distrupted to be energetically neutral

Answer 1

If AsO43- is present then this can bind to G-3-P instead of PO43-, meaning 1,3,BPG will not be formed -
This means when AsO3 is cleaved instead of the PO3 group the energy is not used to posphorylate ADP -> means that the process only produces 2 ATP and uses 2 ATP - Doesnt produce NADH

No energy gained

Question 2

What are the two phases of glycolysis

Answer 2

The energy investment phase - burns 2 ATP to phosphorylate glucose twice

Energy return phase - Hydrolysise Phosphates + oxidation to create 2 ATP and NADH, both 3c molecules undergo the same process

Question 3

What are the properties of NAD

Answer 3

Is a B3 dirrivative
- low conc in cell
- has 2 states - NAD+ -> NADH/H+
- holds 2 reduction equivilants

Question 4

What is the overall reaction for glycolysis

Answer 4

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

Overall negative Gibbs energy -> energetically favourable

Question 5

What are the properties of CoA

Answer 5

B5 dirrivative
- 2 phases, CoASH -> Acyl-COA
- Carrys an acyl group of 2C-> any length C
- Thiol group oxidised to carry acyl group

Question 6

What are the two methods which can produce ATP

Answer 6

1. Substrate level phsophorylation - Energy from bond clevage of substrate used to phosphrylate ADP->ATP
2. Oxidative phosphorylation

Question 7

How do chemical gradients + coupled reactions assist reaction pathways

Answer 7

Chemical gradients can be used when a reaction is two way to drive substrate-> product down pathway. Assuming product is being used to progress the pathway

Reaction coupling can be done to enable a non-spontaneous reaction to spontaneous occur by pairing it with a second substrate (normally ATP) - when deta G summed must be negative overall

Question 8

How is pyruvate processed in arobic conditions

Answer 8

Undergoes oxidative decarboxylation
removal of carbon + oxidising NAD
Products: Acetyl-CoA, NADH, CO2

occur in mitochondrial matrix

Question 9

How is pyruvate processed in anarobic conditions

Answer 9

Pyruvate reduced to lactate - Enables oxidation of NADH to regenerate NAD+
Enables gycolysis to continue working as coenzyme is regenerated
- Common in muscles during arobic excersis + RBC