7 May 2020
Response to exercise.
Complete the table in your book to show the
similarities and differences between aerobic and
anaerobic respiration:
Similarities between aerobic
and anaerobic respiration
Release energy
Uses glucose
Happens in cells
How is anaerobic respiration
different to aerobic?
Produces lactic acid
Does not require oxygen
Produces less energy
Creates an oxygen debt
Lesson Objective:
To develop an understanding of how the body
responds to exercise.
Learning outcomes
Be able to describe the immediate effect of exercise on
the body.
Be able to explain the importance of repaying the “oxygen
debt” for getting rid of lactic acid.
Be able to analyse graphical data to compare levels of
fitness in individuals.
How do cells get oxygen and energy?
How do cells get oxygen and energy?
During exercise
During exercise what are the changes that occur in the
body?
 the heart rate increases
 the rate and depth of
breathing increases
 the arteries supplying
the muscles dilate.
Exercise
increases
muscle
contraction.
Why do these
changes
occur?
These changes increase blood flow to the muscles,
which increases the supply of oxygen and glucose for
respiration and removes carbon dioxide more quickly.
Exercise
During vigorous exercise, your body can’t supply oxygen
to your muscles quickly enough, so they will respire
anaerobically.
This causes a lactic acid build up, which is painful.
Long periods of exercise will also deplete glycogen
stores and cause muscle fatigue – muscles get tired and
stop contracting efficiently.
Anaerobic respiration will leave you with
an oxygen debt.
Oxygen debt
(F)
The oxygen debt is:
The amount of extra oxygen your body
needs after exercise
You need to “repay” the oxygen that you didn’t get to
your muscles in time, because you lungs, heart and blood
couldn’t keep up wit the demand
Your breathing rate will remain high to get more oxygen
into the blood and your heart rate will remain high to
transport the oxygen to your muscles.
Oxygen debt
(H)
The extra oxygen that “repays” the oxygen debt is
needed to react with the lactic acid in the muscles to
form carbon dioxide and water.
The amount of extra oxygen your body
needs after exercise to react with
(oxidise) the build up of lactic acid and
remove it from the cells
Lactic acid + oxygen
Carbon dioxide + water
Your breathing rate and your heart rate will remain
high whilst there are high levels of lactic acid and
carbon dioxide to deliver more oxygen to the cells and
remove the carbon dioxide.
Removing lactic acid
Lactic acid can also be removed by being transported to
the liver in the blood and being converted back to
glucose.
How does exercise affect HR?
Recovery period
During the time that the oxygen debt is being paid back,
the heart rate and breathing rate are high.
This is known as the recovery period.
Spirometer
A spirometer can be used to measure the air capacity of
the lungs.
Effect of exercise
Complete the exam questions
Check your learning
Check your learning
1
50
1.25
Check your learning
• increases at first and levels off
ignore subsequent decrease
1
• suitable use of numbers eg rises to 10 / by 9 (dm3 per min)
or
increases up to 1.5 (min) / levels off after 1.5 (min) (of x axis
timescale)
allow answer in range 1.4 to 1.5
or
after the first minute (of the run)
1
Check your learning
• supplies (more) oxygen
• supplies (more) glucose
1
1
need ‘more/faster’ once only for full marks
allow removes (more) CO2 / lactic acid / heat as an
alternative for either marking point one or two, once
only
• for (more) respiration
• releases (more) energy (for muscle contraction)
do not allow energy production or for respiration
1
1
Check your learning
Check your learning
a)
(before exercise) – 9 to 11 and (after exercise) – 12 or 13
both correct
(b)
0.75 to 0.90
ignore working or lack of working
1
eg. 2.35 – 1.55 or
or other suitable figures
for 1 mark
2
Check your learning
any four from:
still need to remove extra carbon dioxide
still need to remove heat / to cool
(some) anaerobic respiration (in exercise)
lactic acid made (in exercise)
oxygen needed to break down lactic acid or suitable
reference to oxygen debt
• lactic acid broken down to CO2 and water or lactic
acid changed into glucose
•
•
•
•
•
Lesson Objective:
To develop an understanding of how the body
responds to exercise.
Learning outcomes
Be able to describe the immediate effect of exercise on
the body.
Be able to explain the importance of repaying the “oxygen
debt” for getting rid of lactic acid.
Be able to analyse graphical data to compare levels of
fitness in individuals.
Long term effects of exercise
What are the long term effects of regular
exercise on the body?
Heart
Heart contracts more
powerfully – increased
stroke volume, which
is the volume of blood
pumped from heart
with each beat.
Breathing
Increase in Vital
Capacity
(amount of air that can
be forcibly exhaled
after breathing in as
much as possible)
Long term effects of exercise
Complete the exam questions
Check your learning
Check your learning
Check your learning
Check your learning
• increased aerobic respiration
or
decreased anaerobic respiration
allow correct equation for aerobic respiration
accept don’t have to respire anaerobically
1
• increased energy supply / need
1
• less lactic acid formed or to breakdown lactic acid or less O2
debt
1
• can do more work or can work harder / faster / longer
accept muscle contraction for work
or less fatigue / cramp / pain
1
Check your learning
Person 1 sends more blood (to muscles / body / lungs)
1
(which) supplies (more) oxygen
1
(and) supplies (more) glucose
1
(faster rate of) respiration or transfers (more) energy for use
ignore aerobic / anaerobic
allow (more) energy release
allow aerobic respiration transfers / releases more energy
(than anaerobic)
do not allow makes (more) energy
1
• removes (more) CO2 / lactic acid / heat
allow less oxygen debt
or less lactic acid made
or (more) muscle contraction / less muscle fatigue
if no other mark awarded, allow person 1 is fitter (than
person 2) for max 1
mark
1
•
•
•
•