Energy transfer in and between organisms - RESPIRATION Flashcards
Where does glycolysis occur?
Cytoplasm
Where does the link reaction occur?
Mitochondrial matrix
Where does the Krebs cycle occur?
Mitochondrial matrix
Where does oxidative phosphorylation occur?
Inner mitochondrial membrane
Give a summary of glycolysis
- Phosphorylation
- Splitting of glucose
Give a summary of the Link reaction
- Decarboxylation
- Dehydrogenation of pyruvate
Give the summary of the Krebs cycle
Cyclical pathway of enzyme controlled reactions
- complete oxidation and breakdown of pyruvate
Give a summary of oxidative phosphorylation
Production of ATP through the oxidation of hydrogen atoms
What is the first step of glycolysis?
- Glucose is phosphorylated using 2x ATP
- Converted into fructose bisphosphate
What is the second step of glycolysis?
Fructose bisphosphate converted into 2x triose phosphate
What is the third step of glycolysis?
- Triose phosphate converted into pyruvate
- NADH+ and 2x ATP produced
What is the net gain of products in glycolysis?
2x ATP and 2x NADH+
What are coenzymes?
Molecules which some enzymes need to function (NOT enzymes themselves)
What is the role of dehydrogenase enzymes?
Catalyses removal of H
What is NAD and what does it get reduced to?
- Coenzyme
- Hydrogen carrier
- Reduced into NADH+
How is pyruvate moved into the mitochondrial matrix?
Active transport
How many carbons does pyruvate have?
3
What is decarboxylation? (Link reaction)
Removal of CO2 from the pyruvate
What is pyruvate converted into during the link reaction?
3C -> 2C
Two carbon compound called Acetyl CoA
What type of reaction is the conversion of pyruvate to Acetyl CoA?
Oxidation reaction
How many times does the Krebs cycle turn during the aerobic respiration of glucose?
Twice
What carbon chains are produced during the Krebs cycle? (starting from 2C)
- Acetyl CoA (2C)
- Citrate (6C)
- Intermediate compound (5C)
- Oxaloacetate (4C)
Where does the electron transport chain occur?
Inner membrane/cristae
How many ATP does the electron transport chain produce?
34 ATP
Which coenzymes are involved in the ETC?
NADH and FADH
Why are electron transferred along a number of carrier molecules at slightly lower energy levels?
- Creates electrochemical gradient with H
- Used to pump H each time
How is substrate level phosphorylation different to oxidative phosphorylation?
Substrate level: Phosphate is provided by another phosphate
Oxidative: Requires ATP synthase to generate ATP
What enzyme removes H from the coenzymes in the ETC?
Dehydrogenase
What happens in the inner membrane stage of the ETC if there is not enough oxygen?
Oxygen is the final electron acceptor
- If there is no oxygen, protons build up
- No ATP is formed
Anaerobic word equations in plants and animals
Plants : Glucose -> Lactate
Animals : Glucose -> CO2 + ethanol
What happens if there is no oxygen?
- The ETC stops functioning
- No more ATP is produced via oxidative phosphorylation
- Reduced NAD and FAD aren’t oxidised by an ETC
- No oxidised NAD and FAD are available for dehydrogenation in the Krebs cycle
- Krebs cycle stops
