3.5.2 Respiration Flashcards
Summarise the 4 stages of aerobic respiration (where they occur and net gains)
- glycolysis
- cytoplasm of cell
- 2 pyruvate, 2 reduced NAD, 2 ATP
- link reaction
- matrix of mitochondria
- 2 acetyl coenzyme A, 2 reduced NAD, 2 CO2
- krebs cycle
- matrix of mitochondria
- 6 reduced NAD, 2 reduced FAD, 2 ATP, 4 CO2 (2 cycles per glucose)
- electron transport chain
- cristae membrane of mitochondria
- 34 ATP (3x10 from reduced NAD, 2x2 from reduced ATP)
- 10 NAD and 2 FAD
- water
List the stages of anaerobic respiration and where they occur
- glycolysis
- cytoplasm of cell
- 2 pyruvate, 2 reduced NAD, 2 ATP
- anaerobic stage (fermentation)
- cytoplasm of cell
- plants and yeast - ethanol, carbon dioxide, NAD
- animals - lactate, NAD
Describe the process of anaerobic stage in plants and yeast
- pyruvate (3c) to ethanol (2c) and carbon dioxide (1c)
- reduced NAD to NAD - NAD regenerated so glycolysis can continue because NAD is reduced in glycolysis
Describe the process of anaerobic stage in animals
- pyruvate (3c) to lactate (3c)
- reduced NAD to NAD - NAD regenerated so glycolysis can continue
- lactate reoxidised back to pyruvate
- or carried to liver via blood and converted to glycogen
Describe the link reaction
- pyruvate actively transported to the matrix
happens twice for each pyruvate - pyruvate (3c) to acetate
- acetate combined with coenzyme A to make acetyle coenzyme A (2c)
- carbon dioxide (1c) produced
- NAD to reduced NAD
Describe glycolysis
- glucose activated by phosphorylation (2 Pi added) lowers activation energy into glucose phosphate
- splitting of glucose phosphate (low activation energy) into 2 triose phosphates
- oxidation of triose phosphate
- production of ATP, 2 pyruvates, 2 reduced NAD
Describe the krebs cycle
- goes round once for each pyruvate
- reduced NAD makes 3 ATP
- reduced FAD makes 2 ATP
- Decarboxylation, CO2 made
- reduced NAD made
- Decarboxylation, CO2 made
- reduced NAD made
- ATP made
- reduced FAD made
- reduced NAD made
- DeNa DeNa A Fa … Na
Explain the electron transport chain - oxidative phosphorylation
- reduced NAD is oxidised into NAD and the hydrogen atom it loses is split into protons and electrons
- as the electrons move along the electron transport chain, in a series of redox reactions, the energy they release is used to pump protons into the inter membrane space
- As the protons move back into the matrix down their concentration gradient, the energy they release is used to add ADP to Pi to make ATP
- Using ATP synthase
- oxygen is the terminal electron acceptor and combines with electrons and protons to produce water
Why does the drop of liquid in the respirometer move towards the woodlouse/plant?
- oxygen taken up and used by organism in aerobic respiration
- carbon dioxide given out is absorbed by potassium hydroxide solution
- decreases in volume, decrease in pressure
Why is temperature a control variable in the respirometer experiment?
- affects enzymes
- affects respiration
What measurements need to be taken in the respirometer experiment to find the rate of aerobic respiration
- mass of organism
- distance and time
- cross sectional area of capillary tube
Describe lipids as an alternative respiratory substrate
- hydrolysed into glycerol and 3 fatty acids
- glycerol is phosphorylated and converted to triose phosphate
- TP enters glycolysis pathway
- fatty acids broken down into 2 carbon molecule that’s converted to acetyle coenzyme A
- which enters Krebs cycle
Describe amino acids as an alternative respiratory substrate
- deaminated- amino group removed
- enter respiratory pathway at different points depending on number of carbon atoms they contain
- 3c - converted to pyruvate
- 4c and 5c - converted to kreb cycle intermediates
