Energy for action topic 7/a=respiration Flashcards
What is the final product formed in glycolysis?
1
Pyruvate.
Glucose needs to be made more reactive before it can be split into two molecules, explain how this activation of glucose occurs.
(2)
- Phosphate is added/phosphorylation of glucose.
- from breakdown of ATP.
Describe the changes occurring in glycolysis during the conversion of intermediate compound 3C to pyruvate.
(2)
- Dehydrogenation/hydrogen released.
- Attaches to NAD.
- Forming reduced NAD.
- Formation of ATP/ via substrate level phosphorylation of ADP.
A glycogen molecule may contain 60,000 glucose units. If 60,000 glucose molecules undergo glycolysis,
- How many molecules of ATP would produced in total (at end of (glycolysis)?
- What would be the net gain of ATP?
- How many hydrogen atoms would be produced?
- How many pyruvate?
- 60,000 x 4 ATP = 240,000
- 60,000 x 2 ATP = 120,000 (2 used in activation of glucose)
- 60,000 x 2 H = 120,000
- 60,000 x 2 Pyruvate = 120,000
Why is the synthesis of ATP via the electron transport chain termed ‘oxidative phosphorylation’?
- Due to the series of redox reactions (oxidation-reduction) occurring as the electrons pass along the electron transport chain; the final electron acceptor is oxygen.
- Phosphate is added to ADP to form ATP, using ATPase, during chemiosmosis.
- Losing energy.
Suggest why the link reaction and the Krebs cycle take place inside the mitochondria.
-Since the electron carries, ETC and ATP synthase are situated inside the inner mitochondrial membrane. This arrangement allows for an organised and sequenced series of steps, resulting in mass production of ATP, than if the reaction took place in the cytoplasm.
Where does glycolysis occur?
Cytoplasm.
Where does the link reaction occur?
Mitochondrial matrix.
Where does the Krebs cycle occur?
Mitochondrial matrix.
Where is the electron transport chain?
Inner mitochondrial membrane.
Suggest what would happen to the Krebs cycle if acetyl coA became unavailable.
(3)
- Krebs cycle would stop.
- 6 carbon compound would not be synthesised.
- 5 carbon compound would not be synthesised.
- Co2 and H reduced.
Describe the fate of reduced NAD in aerobic respiration.
4
- Reduced NAD from glycolysis enters mitochondria.
- Moves to inner membrane of mitochondrion.
- Becomes oxidised NAD+.
- As electrons transferred to electron transport chain.
- Hydrogen ions pumped into membrane space.
- NAD returns to Krebs cycle/matrix.
What are the two types of anaerobic respiration?
- Ethanol fermentation- takes place in plants and yeast.
- Lactate fermentation- takes place in animals.
What stage do both types of respiration (aerobic and anaerobic) start with?
-Glycolysis.
What is the net gain of glycolysis?
-2ATP molecules and 2NADH molecules.