Respiration Study Guide with Accurate
Solutions
Glucose -pyruvate-ethanol and co2
stage 1 stage 2
Where in a cell does stage 1 occur?
(ii) Explain how stage 2 enables stage 1 to continue. - ANS-Cytoplasm/cytosol;
Regenerates/produces NAD / oxidises reduced NAD;
NAD reduced in stage 1/glycolysis / NAD accepts hydrogen
in stage 1/glycolysis;
Note: penalise use of NADP for first marking point obtained.
Do not accept NAD accepts only protons but allow accepts protons and electrons.
Aerobic respiration produces more ATP per molecule of glucose than anaerobic
respiration. Explain why. - ANS-Oxygen is final/terminal (electron) acceptor / oxygen
combines with electrons and protons;
(Aerobic respiration) oxidative phosphorylation / electron transfer chain;
Anaerobic (respiration) only glycolysis occurs / no Krebs / no link reaction;
(b) Other substances are produced in the Krebs cycle in addition to the carbon
compounds shown in the diagram. Name three of these other products. - ANS-reduced
NAD / NADH / NADH2; reduced FAD / FADH / FADH2; ATP;
In respiration in cells,
(i) where does glycolysis take place
.............................................................................................................
(ii) where, exactly, is the electron transfer chain found? - ANS-Cytoplasm (of cell);
Accept sarcoplasm/cytosol
In membranes/cristae (of mitochondria);
Reject matrix of mitochondria
Explain the effect of nitric oxide. - ANS-NO stops uptake/use of oxygen (by cells);
Stops (electron transport chain of) respiration;
Accept ‒ stops oxidative phosphorylation
NO changes shape of protein (in chain);
Oxygen no longer required as final electron acceptor (however stated);
, Accept ‒ protein denatured or description
As oxygen conc. gets lower effect of NO lasts longer, because NO more likely to
interact with protein;
During respiration where, exactly, in a cell does each of the following occur?
(i) Glycolysis - ANS-Cytoplasm;
During respiration where, exactly, in a cell does each of the following occur
Electron transfer chain - ANS-Inner membrane of mitochondrion Icristae;
Without oxygen, less ATP is produced by respiration. Explain why. - ANS-Oxygen is the
termina/ acceptor;
(No) electron transfer chain / proton transfer / no oxidative phosphorylation;
Accept ETC abbreviation
Which produces most of the ATP (in aerobic respiration); Only glycolysis takes place;
Pyruvate used to make lactate;
Accept lactic acid
Only produces (net) 2 ATP (per molecule of glucose);
The diagram shows apparatus used to measure the oxygen uptake of snails that live on
the seashore. The apparatus was kept at a constant temperature.
Explain the purpose of the strip of filter paper in the potassium hydroxide solution. -
ANS-to increase surface area (for carbon dioxide absorption);
The level of liquid in the right-hand side of the manometer went down during the
experiment. Explain why. - ANS-oxygen is used / carbon dioxide emitted is absorbed;
so decrease in volume / pressur
What measurements are needed to calculate the rate of oxygen uptake by the snails in
mm3 g-1 h-1? - ANS-change of level of (manometer) liquid over time; bore of tube;
mass of snails;
time interval
(ii) Explain why valid conclusions cannot be drawn about the trends in oxygen uptake at
temperatures of 25 °C and above. - ANS-standard deviations high; means unreliable;
When glucose is respired what happens to the energy which is not incorporated into
ATP? - ANS-released as heat;
When one mole of glucose is respired anaerobically, only 2 moles of ATP are produced.
Explain why less energy is released in anaerobic respiration. - ANS-glucose only partly
broken down / only broken down to lactate;
Solutions
Glucose -pyruvate-ethanol and co2
stage 1 stage 2
Where in a cell does stage 1 occur?
(ii) Explain how stage 2 enables stage 1 to continue. - ANS-Cytoplasm/cytosol;
Regenerates/produces NAD / oxidises reduced NAD;
NAD reduced in stage 1/glycolysis / NAD accepts hydrogen
in stage 1/glycolysis;
Note: penalise use of NADP for first marking point obtained.
Do not accept NAD accepts only protons but allow accepts protons and electrons.
Aerobic respiration produces more ATP per molecule of glucose than anaerobic
respiration. Explain why. - ANS-Oxygen is final/terminal (electron) acceptor / oxygen
combines with electrons and protons;
(Aerobic respiration) oxidative phosphorylation / electron transfer chain;
Anaerobic (respiration) only glycolysis occurs / no Krebs / no link reaction;
(b) Other substances are produced in the Krebs cycle in addition to the carbon
compounds shown in the diagram. Name three of these other products. - ANS-reduced
NAD / NADH / NADH2; reduced FAD / FADH / FADH2; ATP;
In respiration in cells,
(i) where does glycolysis take place
.............................................................................................................
(ii) where, exactly, is the electron transfer chain found? - ANS-Cytoplasm (of cell);
Accept sarcoplasm/cytosol
In membranes/cristae (of mitochondria);
Reject matrix of mitochondria
Explain the effect of nitric oxide. - ANS-NO stops uptake/use of oxygen (by cells);
Stops (electron transport chain of) respiration;
Accept ‒ stops oxidative phosphorylation
NO changes shape of protein (in chain);
Oxygen no longer required as final electron acceptor (however stated);
, Accept ‒ protein denatured or description
As oxygen conc. gets lower effect of NO lasts longer, because NO more likely to
interact with protein;
During respiration where, exactly, in a cell does each of the following occur?
(i) Glycolysis - ANS-Cytoplasm;
During respiration where, exactly, in a cell does each of the following occur
Electron transfer chain - ANS-Inner membrane of mitochondrion Icristae;
Without oxygen, less ATP is produced by respiration. Explain why. - ANS-Oxygen is the
termina/ acceptor;
(No) electron transfer chain / proton transfer / no oxidative phosphorylation;
Accept ETC abbreviation
Which produces most of the ATP (in aerobic respiration); Only glycolysis takes place;
Pyruvate used to make lactate;
Accept lactic acid
Only produces (net) 2 ATP (per molecule of glucose);
The diagram shows apparatus used to measure the oxygen uptake of snails that live on
the seashore. The apparatus was kept at a constant temperature.
Explain the purpose of the strip of filter paper in the potassium hydroxide solution. -
ANS-to increase surface area (for carbon dioxide absorption);
The level of liquid in the right-hand side of the manometer went down during the
experiment. Explain why. - ANS-oxygen is used / carbon dioxide emitted is absorbed;
so decrease in volume / pressur
What measurements are needed to calculate the rate of oxygen uptake by the snails in
mm3 g-1 h-1? - ANS-change of level of (manometer) liquid over time; bore of tube;
mass of snails;
time interval
(ii) Explain why valid conclusions cannot be drawn about the trends in oxygen uptake at
temperatures of 25 °C and above. - ANS-standard deviations high; means unreliable;
When glucose is respired what happens to the energy which is not incorporated into
ATP? - ANS-released as heat;
When one mole of glucose is respired anaerobically, only 2 moles of ATP are produced.
Explain why less energy is released in anaerobic respiration. - ANS-glucose only partly
broken down / only broken down to lactate;
