Week 13: Fate of pyruvate Flashcards
Are there limited amounts of NAD+ in a cell?
YES
what is NAD+ derived from?
Niacin (vitamin)
What does glycolysis reduce NAD+ to?
NADH + H+
What must happen to NADH to allow glycolysis to continue?
re-oxidised
NAD+ regenerated through metabolism of pyruvate
What two conditions can glycolysis be in?
aerobic & anaerobic
What 2 processes occur in aerobic conditions?
glycolysis and cellular respiration
What 2 processes occur in anaerobic conditions?
glycolysis and fermentation
What 2 products occur with aerobic conditions?
CO2 & H20
What 2 products occur with anaerobic conditions?
alcohol & lactate
What 2 types of anaerobic pathways are there?
lactic acid fermentation
alcohol fermentation
What is the pathway of lactic acid fermentation?
Pyruvate————> 2X lactate
lactate
dehydrogenase
NADH—–> NAD+ (reduced)
What is the pathway of alcohol fermentation?
Pyruvate————> acetaldehyde ———–> ethanol
(CO2) alcohol
dehydrogenase
NADH—>NAD+
How much ATP does lactate fermentation produce?
2ATP
What causes muscle soreness?
Lactate produced due to low pH
Where is lactate elimninated?
liver, heart and resting
What are the products of alcohol fermentation?
2 ethanol + 2CO2 + 2ATP
Steps in aerobic respiration?
(Glycolysis) glucose–> pyruate 3C –> pyruvate ox –>
2 x acetyl groups as acetyl-Co-A (2C) —> citric acid cycle
—> electron transport/ATP synthase
What are the 2 acetyl groups in the form of?
Acetyl-Co-A
How much ATP is produced by glycolysis?
2ATP
How much ATP is produced by Citric acid cycle?
2 ATP
How much ATP is produced by the electron transport chain?
28 ATP
Where are enzymes for TCA found?
Matrix
Where is pyruvate oxidised?
Matrix to ACoA
How does pyruvate enter the mitochondrial matrix?
Specific transporter
What complex catalyses pyruvate to Acetyl-Co-A?
Pyruvate dehydrogenase complex (PDC)
What does PDC do?
catalyses the oxidative decarboxylation of pyruvate to acetyl-Co-A
What 3 enzymes are involved in the actual reaction mechanism of PDC?
E1, E2, E3
What 2 enzymes are involved in the control of PDC?
kinase & phosphatatse
What 5 Co-enzymes are involved in PDC?
thiamine, lipoic acid, coenzyme A, FAD, NAD+
Is pyruvate to acetyl-Co-A irreversible?
YES