chapter 18 - respiration Flashcards
What are the differences between aerobic respiration and anaerobic respiration?
Aerobic respiration
- needs oxygen
- more efficient (more atp per molecule of glucose)
- complete breakdown of glucose
- slow
Anaerobic respiration
- doesn’t need oxygen
- less efficient
- incomplete breakdown of glucose
- makes harmful waste products (lactic acid and ethanol)
- fast
What are the stages of aerobic and anaerobic respiration?
Aerobic
- glycolysis
- link reaction
- Krebs cycle
- oxidative phosphorylation
Anaerobic
- glycolysis
Where does glycolysis, link reaction, Krebs cycle and oxidative phosphorylation take place?
- glycolysis, cytoplasm
- link reaction, matrix
- Krebs cycle, matrix
oxidative phosphorylation, inter membrane
What is the process of glycolysis?
- glucose(6C) is phosphorylated into hexose biphosphate(6C)
- hexose biphosphate is unstable and so splits into two molecules of TP(3C)
- TP is then oxidised into pyruvate(3C)
What is the net yield gained after the glycolysis stage of respiration?
- 2 ATP
- 2 NADH
What happens after glucose is finally converted into pyruvate?
- pyruvate is actively transported into the matrix for the link reaction
What happens in the process of the link reaction?
- pyruvate is decarboxylated and dehydrogenated into acetate
- acetate combines with coenzyme A to form acetyl coenzyme A
What are the products of the link reaction per reaction and per glucose
per reaction
- 1 CO2
- 1 NADH
per glucose
- 2 CO2
- 2 NADH
What is the process of the Krebs cycle?
- Acetyl coenzyme A delivers an acetyl group to the Krebs cycle and the coenzyme is recycled (goes to the Krebs cycle)
- acetyl group combines with oxaloacetate(4C) to form citrate(6C)
- citrate is then decarboxylated and dehydrogenated producing one NADH and one CO2 forming a 5 carbon compound
- The 5 carbon compound is then further decarboxylated and dehydrogenated to eventually regenerating oxaloacetate
- during the regeneration 1 CO2, 2 NADH, 1 FADH and 1 ATP is produced(atp via substrate level phosphorylation)
What is substrate level phosphorylation?
- is the creation of ATP without ATP synthase instead phosphate is added to ADP via another molecule
What is the process of oxidative phosphorylation?
- electrons and protons are provided from the reduced coenzymes(NADH,FADH)
- electrons move down the electron transport chain in a series of redox reaction
- this releases energy which is used to create a proton gradient
- protons diffuse down their electrochemical gradient thorough ATP synthase (chemiosmosis)
- this provided energy for ADP + Pi = ATP
- oxygen is the final electron acceptor and combines with electrons and protons to form water
What is chemiosmosis?
- its where protons move down their electrochemical gradient through ATP synthase
What are the similarities and differences between mammals and plants respiring anaerobically?
similarities:
- NAD is recycled
differences:
- in plants the pyruvate is decarboxylated
- in plants pyruvate is converted into ethanal then into ethanol whereas in mammals pyruvate is converted into lactate
why does anaerobic respiration produce less ATP than aerobic respiration?
- the products of anaerobic are not totally respired, they still have chemical energy
- no oxygen as the final acceptor meaning there is no link reaction, Krebs cycle or oxidative phosphorylation
What is a respiratory substrate?
- Any biological molecule that can be respired to release energy (carbohydrates, lipids and proteins)
