2.2.5 Respiration FMQuiz Homework Solution
Q. Yeast cells produce ethanol in fermentation. Is
this process affected by temperature? Explain your
answer.
A. Yes. Rate of enzyme action affected by
temperature
Q. Distinguish between aerobic and anaerobic
respiration.
A. Aerobic respiration requires oxygen or anaerobic
respiration does not
Q. Write a balanced equation to summarise
aerobic respiration.
A.
C6H12O6 + 6O2  ENERGY + 6CO2 + 6H2O
Q. To what is pyruvic acid converted under
anaerobic conditions in yeast?
A. Ethanol and CO2
Q. Under aerobic conditions pyruvic acid is
converted to an acetyl group and in the process a
small molecule is released. Name this molecule.
A. Carbon dioxide
Q. In respiration acetyl co-enzyme A enters a cycle
of reactions. What name is given to this cycle?
A. Kreb’s cycle
Q. To what is pyruvic acid converted under
anaerobic conditions in a human muscle cell?
A. Lactic acid
Q. Where in the cell does the first stage of
respiration occur?
A. Cytoplasm
Q. Is oxygen required for the first stage of
respiration?
A. No
Q. Give two industrial uses of the anaerobic
respiration of yeast.
A. Baking, brewing
Q. To what might pyruvic acid be converted, in the
absence of oxygen?
A. Lactic acid or Ethanol + CO2
Q. What is the final product of the first stage of
respiration under aerobic conditions?
A. Pyruvic acid (Pyruvate)
Q. Where in the cell does Kreb’s Cycle take place?
A. Mitochondrion
Q. Pyruvic acid is used for the second stage of
respiration. Where does this second stage take
place?
A. Mitochondrion
Q. What is the cytosol?
A. Cytoplasm minus organelles or liquid part of
cytoplasm
Q. If conditions in a human muscle cell become
anaerobic pyruvic acid is converted to another
substance. Name this other substance.
A. Lactic acid
Q. What is fermentation?
A. Anaerobic respiration or respiration that
produces lactic acid or ethanol CO2
Q. When lactic acid builds up in the blood, a person
is in oxygen debt. This debt must eventually be
paid. Suggest how the debt is paid.
A. Increased breathing (deeper or faster) or
oxidation of lactic acid
Q. What is the first stage process of respiration
called?
A. Glycolysis
Q. In the first stage of respiration there is a release
of ATP as glucose is converted to another
substance. Name this other substance.
A. Pyruvic acid (Pyruvate)
Q. Is oxygen required for the second stage of
aerobic respiration?
A. Yes
Q. Suggest a situation in which some cells in the
human body may not be able to engage in the
second stage of aerobic respiration.
A. Lack of oxygen or strenuous exercise or
restricted blood supply
Q. What term is used to describe respiration in
which only Stage 1 occurs?
A. Anaerobic or Fermentation
Q. Name an organism that is used in industrial
fermentation.
A. Yeast
Page 1 of 1