Lecture 24 - Glycolysis Flashcards
What is the driving force for this reaction?
ATP hydrolysis
Describe this reaction:
1st activation of glucose, phosphate group added
What type of reaction is this and how is it driven forwards?
Rearrangement, driven forwards when not under standard conditions.
Describe this reaction:
2nd activation of glucose, coupled to ATP hydrolysis
What is the result of this reaction?
G-3-P, 2 x 3C and 1P molecule
What drives the rearrangement of dihydroxyacetone phosphate to G-3-P?
Low conc. of G-3-P
What powers the addition of phosphate from solution?
Oxidation of G-3-P, no ATP required
What is the role of NAD+?
Reduction to NADH provides oxidising power
What feature of 1,3-BPG allows this reaction?
1st carbon is very reactive, allows phosphate to be easily removed.
What type of reaction is this and where is the energy coming from?
1st Substrate level phosphorylation, energy is released when phosphate cleaved and used for SLP, ATP released
What type of reactions are these and what is their purpose?
Rearrangement, gets molecule into a form that enables following reactions
What is the purpose of this reaction?
2nd Substrate level phosphorylation, energy captured in ATP
Where does aerobic oxidation occur?
Mitochondrial matrix
What is the role of NAD+ in aerobic oxidation?
Captures energy which is then used to add CoA to 2C chain to produce acetyl-CoA
What does the formation of lactate allow for?
Regeneration of NAD+, which means sufficient NAD+ for G-3-P dehydrogenase reaction and glycolysis can continue when no O2 present.
Why is the oxidation of glyceraldehyde-3-phosphate essential for glycolysis to make and ATP profit?
Results in 1,3-BPG which has a high energy phosphate bond, Conserves energy in NADH which is used in oxidative phosphorylation to produce ATP
What is substrate level phosphorylation?
Direct use of energy from a substrate molecule to drive synthesis of ATP. One way is through cleavage of phosphate ester bond.
What are the two types of reactions that involve energy conversions?
- Those involving ATP and ADP
- Redox reactions, fuel molecules are oxidised
What is this molecule?
NAD
What is NAD derived from?
Niacin, (vitamin B3)
What does NADH (reduced form) carry?
2 x e-
1 x H+
NAD undergoes a _________ reduction.
two-electron (accepts two reducing equivalents).
What is the overall reaction for glycolysis?
What is coenzyme A (Co-A) derived from?
Pantothenic acid (vitamin B5)
What does Co-A carry?
acyl groups, (2C - long C chains)
What are the two forms of Co-A?
Free coenzyme: Co-ASH
Acyl Group attached: Acyl-CoA (different to acetyl-CoA)
What stage glycolysis does arsenic effect?
1st Substrate level phosphorylation, so no energy captured and no net gain of APT
If arsenic present which molecule would be changed?
1,3-BPG for 1-arseno-3-phosphateglycerate. Arsenate substitutes for phosphate.
Why does arsenate prevent ATP profit being made?
Arsenate substitutes for phosphate on 1,3-BPG so no high energy bond to cleave, therefore no energy released, and no ATP made
