respiration exam questions Flashcards
describe the process of glycolysis (4)
-glucose phosphorylated to glucose phosphate using ATP
-triose phosphate oxidised to pyurvate
-NAD reduced
-net gain of ATP
malonate inhibits a reaction in the krebs cycle.
explain why malonate would decrease the uptake of oxygen in a respiring cell. (2)
-oxygen is the final electron acceptor
-less reduced coenzymes.
describe how acetylcoenzyme a is formed in the link reaction. (2)
addition of coenzyme a
-hydrogen is oxidised and carbon dioxide is released.
a scientist investigated the effect of the enzyme inhibitor malonate on this reaction. the structure of malonate is very similar to the structure of succinate.
the scientist added malonate and the respiratory substance, pyruvate to a suspension of isolated mitochondria.
she also bubbled oxygen through the suspension.
explain why the scientist did not use glucose as the respiratory substance for these isolated mitochondria. (2)
-glucose cannot cross mitochondrial membrane/pyurvate can.
-glucose is used in glycolysis.
ATP is useful in many biological processes. Explain why. (4)
-phosphorylates compounds
-making them more reaction
-immediate energy source
-releases energy in small, manageable amounts
Describe how ATP is made in mitochondria. (6)
-substrate level phosphorylation
-during krebs cycle
-electrons released by reduced coenzymes
-transported through electron transport carrier chain
-release energy
-ADP +pi
-protons move into intermembrane space
-ATP synthase.
explain why converting pyruvate to lactate allows the continued production of ATP during aerobic respiration. (2)
-produces NAD
-NAD used in glycolysis.
in muscles some of the lactate is converted to pyruvate when they are well supplied with oxygen. Suggest the advantage of this. (1)
-pyruvate used in aerobic respiration/can enter the link reaction.
yeast can also respire aerobically. the student repeated the experiment with a fresh sample of yeast in glucose solution but without the oil. All other conditions remained the same.
Explain what would happen to the volume of gas in the syringe if the yeast were respiring anaerobically.
-stays the same
-oxygen uptake is the same as carbon dioxide release.
respiration produces more ATP per molecule of glucose in the presence of oxygen than it does when oxygen is absent. Explain why. (2)
-oxygen is the terminal electron acceptor
-oxidative phosphorylation.
the scientist measured the uptake of oxygen by the mitochondria during the investigation. the uptake of oxygen decrease when malonate was added. Explain why (2)
-krebs cycle inhibited
-co enzymes not reduced
-hydrogen ions not passed through electron transport chain
-oxygen is not final electron acceptor.
the scientist measured the uptake of oxygen by the mitochondria during the investigation. the uptake of oxygen decrease when malonate was added. Explain why (2)
-krebs cycle inhibited
-co enzymes not reduced
-hydrogen ions not passed through electron transport chain
-oxygen is not final electron acceptor.
sodium azide is a substance that inhibits the electron transport chain in respiration. The student repeated the investigation but added sodium azide after 4 hours.
Suggest and explain how the addition of sodium azide would affect oxygen uptake and the production of ethanol (3)
-reduced uptake of oxygen
-oxygen is termainal electron acceptor
-more ethanol produced
the student repeated experiement one using seeds which are respiring anaerobically.
what would happen to the level of coloured liquid in the right hand side of the manometer tube. explain your answer (2)
-stays the same
-no oxygen used
descrbe role of inner mitochondrial membrane in producing ATP. (3)
-electrons transferred through electron transport chain
-energy used to pump hydrogen ions into inner mitochondrial membrane
-energy used to combine ADP + pi to produce ATP.
explain how temperature would affect the rate of carbon dioxide production. (2)
-less enzyme activity
-fewer enzyme substrate complexes form.
the rate of co2 production was higher when the apples were in nitrogen compared to when in air. Explain why (3)
-anaerobic respiration
-anaerobic respiration is less efficient/produces less ATP
-so higher rate of anaerobic respiration to produce the same amount of ATP
both experiemnts were carried out at the same temperature. explain why (2)
-affects enzymes
-affects respiration
the level of coloured liquid in the right hand side of the manometer tube went down during the experiment. Explain why (2)
-oxygen used by seeds
-carbon dioxide given out absorbed by potassium hydroxide
-decrease in volume/pressure
plants produce ATP in their chloroplasts during photosynthesis. They also produce ATP during respiration.
Explain why it is important for plants to produce ATP both during respiration and photosynthesis. (6)
-plants use more ATP than produced during respiration
-ATP used for protein synthesis
-ATP used for active transport.
-ATP cannot be stored
-some tissues do not produce ATP
-in the dark- no photosnythesis- no ATP produced.
what measurements should the student have taken to calculate the rate of aerobic respiration? (2)
-diameter of tubing
-distance moved by drop and time
-mass of woodlouse.
apart from respiration, give three uses of ATP in a liver cell (3)
-active transport
-protein synthesis
-source of energy/phosphate
human skeletal muscles can respire both aerobically and anaerobically. Describe what happens to pyruvate in anaerobic respiration and explain why anaerobic respiration is advantageous to human skeletal muscles (4)
-lactate is produced
-NAD regenerated
-glycolysis can continue
-can still release energy/form ATP
explain why converting pyruvate to ethanol is important in allowing the continued production of ATP in anaerobic respiration. (2)
-NAD regenerated
-glycolysis can continue
2 ways in which anaerobic respiration of glucose is different in yeast cell compared to muscle cell (2)
yeast cell produces ethanol/muscle cell produces lactate
only yeast cell produces carbon dioxide
explain why the concentration of oxygen and amount of ATP fell during the investigation (2)
ADP + Pi form ATP/substrate level phosphorylation
oxygen is terminal electron acceptor
without oxygen , less ATP is produced by respiration. Explain why (2)
-only glycolysis can occur
-oxygen is terminal electron acceptor
-no electron transfer chain
why did the coloured liquid move to the right (2)
-carbon dioxide produced by aerobic respiration
-increase in pressure/volume.
3 uses of ATP in a liver cell (3)
protein synthesis
active transport
cell division/mitosis
phagocytosis
source of energy/phosphate
how respiration in a muscle cell and yeast cell are similar (2)
ATP formed
NAD reduced
why was the apparatus left for 10 minutes (3)
allow rate of respiration of seeds to stabilise
equillibrium reached
allow for pressure changes in apparatus
how is NADP reduced? (2)
by electrons
from photolysis
the role of chlorophyll in photolysis (3)
absorbs light energy
loses electrons
accepts electrons from water
