Respiration Flashcards
Describe the process of glycolysis? (5)
- Occurs in the cytoplasm
- Phosphorylation of glucose using ATP
- Oxidation of triose phosphate to pyruvate
- Net gain of ATP
- NAD is reduced
Describe the link reaction? (4)
- Occurs in the matrix (mitochondrion)
- Pyruvate is oxidised + decarboxylated into acetate
- Produces CO2 + NADH
- Acetate combines with coenzyme A to produce Acetyl CoA
Describe the Krebs cycle? (6)
- Acetyl CoA combines with a 4-carbon molecule to form a 6-carbon molecule
- 6-carbon molecule is decarboxylated, releasing CO2 so goes down to a 5-carbon molecule
- NAD gets reduced into NADH
- Being regenerated into 4C molecule
- ATP is produced due to substrate-level phosphorylation
- NADH and FADH is produced by oxidative phosphorylation
What is the electron transport chain? (5)
- NADH is oxidised so loses a H
- Electrons pass down the ETC
- Electrons lose energy for the proton pump or heat energy
- H+ diffuse down proton gradient via ATPsynthase by facilitated diffusion
- Oxygen is the final electron acceptor
Water is a waste product of aerobic respiration. Describe how water is formed at the end of aerobic respiration? (2)
- Oxygen is the final electron acceptor
- Combines with electrons and protons
What happens if oxygen is inhibited in the ETC? (2)
- Would be a backup of electrons along the ETC
- Respiration will stop
Describe the roles of coenzymes + carrier proteins in the synthesis of ATP? (3)
- Electrons transferred from through a series of redox reactions
- Energy is released as electrons passed along
- Energy used to synthesise ATP from ADP and Pi
Describe how ATP is made in mitochondria? (6)
- ATP produced in Krebs cycle
- Electrons released from NADH/FADH
- Electrons pass along through ETC
- Energy released
- ADP + Pi ———> ATP
- by ATPsynthase
Describe the events of oxidative phosphorylation? (6)
- NAD reduced to NADH
- ETC on inner membrane
- Electrons transferred through ECT by series of redox reactions
- Energy released as electrons passed on
- Protons pumped into intermembrane space
- Energy used to synthesise ATP from ADP + Pi
Describe how oxidation takes place in glycolysis + Krebs cycle?
- Removal of hydrogen/dehydrogenation
- By dehydrogenase
- H accepted by NAD
- In Krebs cycle, FAD used aswell
What are alternative respiratory substrates? Used for? (3)
- Glycerol is phosphorylated + converted to TP
- Fatty acids are broken down into 2C + converted into acetyl CoA
- Deamination of amino acids
What reactions stop if theres no oxygen? Why?
Link reaction, Krebs cycle, Electron transport chain
No oxygen to act as the final electron acceptor
Anaerobic respiration in animals?
Anaerobic respiration in plants, yeast + bacteria?
Explain how the amount of ATP is increased by reactions occurring inside a mitochondrion? (7)
Give 2 reasons why respirometer was left for 10 minutes when it was the first placed in the water bath?
- Equilibrium reached
- Allow for pressure change in apparatus
- Allow respiration rate to stabilise
Explain why the scientist didn’t use glucose as the respiratory substrate for these isolated mitochondria?
- Glucose is used in glycolysis
- Can’t cross the mitochondrial membrane
