AQA · GCSE · Combined Science

Course version: 8464 · Version from Sept 2018

Response to exercise: During exercise the human body reacts to the increased demand for energy.

Q: How do I revise Response to exercise: During exercise the human body reacts to the increased demand for energy. for GCSE?

Read the notes on Response to exercise: During exercise the human body reacts to the increased demand for energy., then test yourself without looking. Answering questions and checking what you missed builds recall faster than re-reading.

Q: Is this Response to exercise: During exercise the human body reacts to the increased demand for energy. guide aligned to the AQA specification?

Yes. This guide is linked to the Response to exercise: During exercise the human body reacts to the increased demand for energy. topic in the AQA GCSE specification.

Exercise raises the rate of respiration in muscle cells because more energy is needed for contraction.

Study notes

From the checked teaching notes for this specification point.

The idea

For example: When a student runs upstairs, breathing quickens and the pulse rises; the body is matching oxygen supply to the higher demand for energy rather than simply becoming tired.

What earns the marks

Exercise increases the rate of respiration in muscle cells, releasing more energy for muscle contraction.
Aerobic respiration needs glucose and oxygen and produces carbon dioxide and water.
The body detects the increased demand and responds with faster breathing, greater breath volume and a faster heart rate.
Blood flow is directed towards active muscles so that more oxygen and glucose arrive and carbon dioxide is removed.

Common mistakes and how to put them right

Saying that exercise creates energy.
Put it right: Energy is transferred, not created; respiration releases energy from glucose.
Confusing breathing with respiration.
Put it right: Breathing moves air into and out of the lungs, while respiration is the chemical process in cells.
Thinking the heart rate rises only to remove carbon dioxide.
Put it right: It also delivers more oxygen and glucose to muscles.

Exam tips

Link every response back to the demand for energy in muscle cells.
Use the terms aerobic respiration, oxygen, glucose and carbon dioxide accurately.
When describing a change, state what increases or decreases and why that helps the muscle cells.

Try the lesson

The start of the Response to exercise: During exercise the human body reacts to the increased demand for energy. lesson, made from checked teaching notes for this specification point.

Have a go first

Which change happens in the human body during exercise because muscles need more energy?

Tip: press 1 to 4 to choose

Listen

Exercise raises the rate of respiration in muscle cells because more energy is needed for contraction. This extra energy comes from aerobic respiration, which requires glucose and oxygen and releases carbon dioxide and water. The body therefore detects a change in its internal environment and responds with coordinated changes, including faster and deeper breathing, a faster heart rate and redistribution of blood towards active muscles. These responses increase the delivery of oxygen and glucose and the removal of carbon dioxide. For example, when a student runs upstairs, breathing quickens and the pulse rises; the body is matching oxygen supply to the higher demand for energy rather than simply becoming tired. A strong answer earns marks for these points. Exercise increases the rate of respiration in muscle cells, releasing more energy for muscle contraction. Aerobic respiration needs glucose and oxygen and produces carbon dioxide and water. The body detects the increased demand and responds with faster breathing, greater breath volume and a faster heart rate. Blood flow is directed towards active muscles so that more oxygen and glucose arrive and carbon dioxide is removed. Exam tip: Link every response back to the demand for energy in muscle cells.

See it

A top-down flowchart. Exercise leads to increased demand for energy in muscle cells. From there the rate of respiration in muscle cells increases, which releases more energy for muscle contraction; aerobic respiration needs glucose and oxygen and produces carbon dioxide and water. The increased demand also leads to the body detecting the change in its internal environment, which leads to three responses: faster and deeper breathing, a faster heart rate, and blood flow directed towards active muscles. All three responses lead to more oxygen and glucose delivered and carbon dioxide removed, which leads to a suitable internal environment being maintained while energy demand is high. — It shows how exercise raises the demand for energy in muscle cells and how breathing, heart rate and blood flow respond to deliver oxygen and glucose and remove carbon dioxide.

Label the diagram

Some boxes have lost their names. Pick the right name for each number.

The diagram again, with 3 boxes numbered instead of named. A top-down flowchart. Exercise leads to increased demand for energy in muscle cells. From there the rate of respiration in muscle cells increases, which releases more energy for muscle contraction; aerobic respiration needs glucose and oxygen and produces carbon dioxide and water. The increased demand also leads to the body detecting the change in its internal environment, which leads to three responses: faster and deeper breathing, a faster heart rate, and blood flow directed towards active muscles. All three responses lead to more oxygen and glucose delivered and carbon dioxide removed, which leads to a suitable internal environment being maintained while energy demand is high.

1Box 1
2Box 2
3Box 3

0 of 3 labelled

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