respiration

Question 1

what is the first stage of aerobic respiration

Answer 1

glycolysis

Question 2

describe the process of glycolysis

Answer 2

phosphorylation of glucose
oxidation of triose phosphate into pyruvate
NAD reduced
net gain of ATP (4 made)
less NADH (2 made)
oxygen is terminal electron acceptor

Question 3

describe the process of the link reaction

Answer 3

pyruvate produced from glycolysis enters the mitochondrial matrix
pyruvate is oxidised to acetate reducing NAD in the process
acetate combines with coenzyme A to produce acytyl to acetyl coenzyme A

Question 4

why is pyruvate converted to lactate in muscle cells during anaerobic respiration

Answer 4

to regenerate NAD
so glycolysis can continue without oxygen

Question 5

investigating rate of respiration:why is the apparatus left for one hour after culture has reached constant temp

Answer 5

so that oxygen is absorbed

Question 6

investigating rate of respiration: why would coloured liquid move to the right in respiration of yeast

Answer 6

anaerobic respiration produces CO2
this causes an increase in gas volume/ pressure

Question 7

describe the part played by the inner mitochondrial membrane in making ATP

Answer 7

site of the electron transport chain
electrons tranferred down the elecrton transport chain
this provides energy to move protons into spaces between membrames
prptons move back into matrix through ATP synthase
emnergy used to combine ADP and Pi

Question 8

anaerobic respiration

Answer 8

glycolysis in cytoplasm same as aerobic
phosphorylation of glucose to glucose phosphate using ATP
production of triose phosphate
oxidation of triose phosphate to pyruvate with a net gain of ATP and NADH.
pyruvate is then converted to ethanol or lactate using NADH
NAD is produced which can be used in further glycolysis.

Question 9

aerobic respiration

Answer 9

pyruvate is oxidised to acetate producing NADH in the process
acetate combines with coenzymeA to form acetyl coenzymeA
acetylcoenzyme A reacts with 4 carbon releasing coenzyme A and producing a 6 C molecule that enters the krebs cycle
in a series of redox reactions the krebs cycle generates reduced coenzymes and ATP by substrate level phosphorylation and carbon dioxide is lost
synthesis of ATP by oxidative phosphorylation is associated with the transfer of electrons down the etc and passage of protons across inner mitochondrial membrane catalysed by ATP synthase embedded in membrane (chemiosmosis)

Question 10

give two advantages of ATP as an energy storage molecule within a cell

Answer 10

cannot pass out of cell
quickly hydrolysed