Carbohydrates 3 Flashcards
How many molecules of G-3-P enter the payoff phase?
2
How many ATP are used in the prepatory phase?
2
How many ATP are made during the payoff phase?
4
What is the first reaction of glycolysis?
Phosphorylation of glucose
How many ATP is used during the first stage of glycolysis? (phosphorylation of glucose) And what enzyme is used?
1 ATPHexokinase
What is the second stage of glycolysis? And what is the enzyme?
Conversion of G - 6 - P to F-6-P Phosphohexose Isomerase
Why does the second step of glycolysis proceed in both directions?
Reaction has a low free energy
What is the stage of glycolysis apart from step 1 (phosphorylation of glucose) that requires ATP?
Phosphorylation of F-6-P to F-1,6 - bisP (stage 3)
What is the catalyst for phosphorylation of F-6-P?
Phosphofructokinase -1
What is the splitting part of Glycolysis?
Step 4 - which is the cleavage F-1, 6-bisP, forms two different triose sugars Catalyst is aldolase
What is stage 5 of glycolysis?
Interconversion of triose sugarsEnzyme used it triose phosphate isomeraseDihydroxyacetone phosphate is converted to glyceraldehyde -3-phosphateForming 2 molecules of G-3-PG-3-P is the only molecule that can enter the payoff phase
Which stage in glycolysis produces 2 molecules of NADH?
Stage 6, the oxidation of G-3-P to 1,3-bisPGThe catalyst is glyceraldehyde - 3 - phosphate dehydrogenaseThe first payoff reaction in glycolysis
Reaction 6 (the oxidation of G-3-P to 1,3-bisPG) is coupled to which other reaction and why?
6 is coupled to 7 because 6 requires a lot of energy whilst 7 gives off a a lot of energy.
Describe reaction 7 and what is the substrate?
P transfer from 1,3-bisPhosphoglycerate to ADP, 2 ATP produced, phosphoglycerate kinase enzyme usedSpontaneous since highly exergonic
What is stage 8?
Conversion of 3, phosphoglycerate to 2, phosphoglycerateEnzyme is phosphoglycerate mutase
What step of glycolysis is enolase used in?
Dehydration 2-PG to PEP (phosphoenolpyruvate)
Where does the ADP in the last stage of glycolysis get the phosphate?
PEP
Describe the last stage of glycolysis
Transfer of P from PEP to ADP2 ATP produced, highly exergonic,Pyruvate producedEnzyme is pyruvate kinase
Where does NAD+ come from in the cell?
Niacin an essential vitamin
What is the difference between substrate level phosphorylation and respiration linked phosphorylation ?
Substrate level - requires soluble enzymes and chemical intermediatesRespiration linked means membrane bound enzymes and gradients of protons
What compound is used to replenish NAD+?
The different fates of pyruvate
What is NAD+ used for?
The reduction of various intermediate metabolites
What are the three fates of pyruvate?
Citric acid cycle, producing water and carbon dioxideFermentation to lactateFermentation to CO2 and Ethanol
How is pyruvate converted into ethanol?
Pyruvate + pyruvate carboxylase = AcetaldehydeAcetaldehyde + Alcohol dehydrogenase + NADH = Ethanol + NAD+
Why can’t we make ATP via oxidative phosphorylation during intense exercise?
Not enough oxygen
How is ATP made instead during intense exercise?
Substrate level phosphorylation producing lactate
Where is the lactate converted into glucose, and what is this process called?
Liver, gluconeogenesis
What is the interaction between the muscle and the liver called?
The cori cycle
What is pyruvate converted into in aerobic conditions?
Acetyl Co-A, in mitochindria, NADH is formed
