2. B2.6 Aerobic and anaerobic respiration
Respiration in cells can take place
aerobically or anaerobically. The energy
released is used in a variety of ways.
The human body needs to react to the
increased demand for energy during
exercise.
3. Candidates should use their skills,
knowledge
and understanding to:
■ interpret the data relating to the effects
of exercise on the human body.
5. Respiration
Respiration is the process of transferring energy
from food molecules in every living cell.
There are two main types of respiration:
aerobic and anaerobic
Aerobic respiration - uses oxygen
Anaerobic respiration - uses no oxygen
All chemical reactions inside cells are
controlled by enzymes.
6. Aerobic Respiration
Words – breathing, energy, respiration, food, bonds
Every life process (e.g. growth) needs ENERGY. __________
is the process our bodies use to produce this energy:
Glucose + oxygen water + carbon dioxide + ENERGY
The glucose we need comes from _____ and the oxygen from
________. Water and carbon dioxide are breathed out. The
MAIN product of this equation is ______. This energy is used
to synthesise a chemical called adenosine triphosphate (ATP),
which transfers energy from chemical _____ to cells in the
body.
7. Aerobic Respiration
Words – breathing, energy, respiration, food, bonds
Every life process (e.g. growth) needs ENERGY. Respiration
is the process our bodies use to produce this energy:
Glucose + oxygen water + carbon dioxide + ENERGY
The glucose we need comes from food and the oxygen from
breathing. Water and carbon dioxide are breathed out. The
MAIN product of this equation is energy. This energy is used
to synthesise a chemical called adenosine triphosphate (ATP),
which transfers energy from chemical bonds to cells in the
body.
8. Anaerobic respiration
Unlike aerobic respiration, anaerobic respiration is when energy is
provided WITHOUT needing _________:
This happens when the body can’t provide oxygen quick enough
for ________ respiration to take place.
Anaerobic respiration produces energy much ______ than aerobic
respiration but only produces 1/20th as much.
Lactic acid is also produced, and this can build up in muscles
causing ______ and an oxygen ______.
This “debt” then needs to be “repaid” by deep breathing to
________ the lactic acid.
Word bank: debt, oxygen, fatigue, oxidise, aerobic, quicker
Glucose lactic acid + a bit of energy
9. Anaerobic respiration
Unlike aerobic respiration, anaerobic respiration is when energy is
provided WITHOUT needing oxygen:
This happens when the body can’t provide oxygen quick enough
for aerobic respiration to take place.
Anaerobic respiration produces energy much quicker than aerobic
respiration but only produces 1/20th as much.
Lactic acid is also produced, and this can build up in muscles
causing fatigue and an oxygen debt.
This “debt” then needs to be “repaid” by deep breathing to
oxidise the lactic acid.
Word bank: debt, oxygen, fatigue, oxidise, aerobic, quicker
Glucose lactic acid + a bit of energy
10. Differences between anaerobic and
aerobic respiration
Aerobic respiration
• Requires oxygen
• Occurs in the
mitochondria of cells
• Produces a lot of ATP
per glucose molecule
• Used when heart rate
and breathing rate
rise
Anaerobic respiration
• Occurs in the
cytoplasm of cells
• Doesn’t require
oxygen
• Used during the first
1-2 minutes of
exercise
• Produces less ATP
per glucose molecule
16. 1 (a) In the summary of aerobic respiration shown below,
choose a word from each of the boxes that best completes the
equation.
(b) (i) State two ways in which the energy released during
respiration is used in all animals.
Build larger molecules
Heat
Movement – muscles contract
17. (ii) How else might the energy released be used in
mammals and birds only?
(iii)Give a further use of the energy released that applies to
plants rather than animals.
Heat
Movement – muscles contract
Plants to build up sugars, nitrates and other
nutrients into amino acids which in turn are
built into proteins
