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Describe the Process of Anaerobic Respiration

In this worksheet, students will describe the process of anaerobic respiration.

'Describe the Process of Anaerobic Respiration' worksheet

Key stage:  KS 4

GCSE Subjects:   Biology: Single Subject, Biology: Combined Science

GCSE Boards:   Pearson Edexcel

Curriculum topic:   Exchange and Transport in Animals

Curriculum subtopic:   Exchange and Transport in Animals

Difficulty level:  

Worksheet Overview

QUESTION 1 of 10

Did you know that Usain Bolt is currently the fastest sprinter in the world? He ran 100 metres in a record 9.58 seconds! 

 

Image of athletes running

 

In order to do this, Usain Bolt’s muscles need to respire super quick. He needs all that energy to sprint so fast. But his body can’t keep up with these demands - it can’t respire fast enough. This is where anaerobic respiration steps in.

 

 

Image of females exercising

 

 

Anaerobic respiration is where glucose breaks down but without oxygen. Energy is released, but not as much as in aerobic respiration. Lactic acid is produced instead of carbon dioxide and water. Lactic acid can cause painful cramps - something we feel in our muscles that stops us from carrying on. To get rid of the lactic acid, the person must breathe in deeply in order to get a good supply of oxygen. You have to keep breathing hard for a while after you stop exercising to get oxygen into your muscles. This will convert the painful lactic acid which has built up, to harmless carbon dioxide and water. The amount of oxygen needed to do this is called the oxygen debt.

Anaerobic respiration can be represented by the word and symbol equation: 


glucose → lactic acid 

C6H120 → 2C3H6O3

 

The reactant in anaerobic respiration is glucose. The product is lactic acid. A small amount of energy is also released.

Anaerobic respiration occurs in the cytoplasm of the cell rather than the mitochondria, as in aerobic respiration.

 

In the following activity, you will describe the process and uses of anaerobic respiration.

Fill in the blanks below describing anaerobic respiration.  

 

When athletes train hard they can respire anaerobically. 

 

Which of the following statements about anaerobic respiration is true?

Lactic acid and carbon dioxide are produced

Lactic acid can build up, causing cramp

Water and carbon dioxide are produced

What is meant by the term oxygen debt? 

The amount of oxygen needed to break up glucose into carbon dioxide and water

The amount of oxygen needed to break up lactic acid into carbon dioxide and water

The amount of oxygen needed to break up lactic acid into energy

What are two differences between anaerobic and aerobic respiration? 

 

Note that ATP is the name for the molecule in cells that carries energy.

 

 1

  ATP is released in both anaerobic and aerobic respiration

 2

 Less ATP is released in anaerobic respiration than in aerobic respiration

 3

 Carbon dioxide isn't produced in anaerobic respiration but is in aerobic respiration

 4

 Glucose is a reactant in aerobic and anaerobic respiration

1 and 4

2 and 3

3 and 4

What is the name of X and Y in the equation below?

 

Image of anaerobic respiration equation

Lucy says the equation for anaerobic respiration in the human body is

glucose → lactic acid + ATP


Terri disagrees and says it's

glucose → carbon dioxide + ATP 

 

Who's correct?

 

 

Karl is at the gym exercising. After a while on the treadmill, he gets cramp in his legs.

 

What must he do to get rid of this cramp?

Karl has to stop exercising and breathe hard to get rid of the lactic acid that has built up in his leg muscles

Karl has to carry on exercising to get rid of the lactic acid that has built up in his leg muscles

Karl needs to get used to the pain and carry on

Why is less energy released from anaerobic respiration than during aerobic respiration?   

It's harder to release energy for anaerobic respiration

The glucose molecules are fully broken down to release energy

The glucose molecules aren't fully broken down to release energy

What do aerobic and anaerobic respiration have in common?

Glucose is a reactant

Oxygen is a reactant

Energy is released

Water is released

John and George are doing laps around the playground for PE. George's legs start to hurt. He tells John that it's lactic acid building up in his muscles. John thinks that this is just an excuse to stop!

 

What do you think?

John is correct, George wants to stop

George is correct, lactic acid is building up from anaerobic respiration

They both really should be doing laps and not talking

  • Question 1

Fill in the blanks below describing anaerobic respiration.  

CORRECT ANSWER
EDDIE SAYS
This activity is useful for making revision notes. Have a few tries if you didn't get it correct the first time around.
  • Question 2

 

When athletes train hard they can respire anaerobically. 

 

Which of the following statements about anaerobic respiration is true?

CORRECT ANSWER
Lactic acid can build up, causing cramp
EDDIE SAYS
How did you do with this one? Remember that this question is asking about anaerobic respiration, so the only product is lactic acid. Lactic acid builds up in muscles causing painful cramps. The athlete would need to stop and breathe quickly and deeply to get rid of the lactic acid.
  • Question 3

What is meant by the term oxygen debt? 

CORRECT ANSWER
The amount of oxygen needed to break up lactic acid into carbon dioxide and water
EDDIE SAYS
The term debt means when you owe someone something, normally money! Here, the body owes oxygen, which is why you are forced to breathe quickly and deeply after exercising hard. As the oxygen gets into your system, the lactic acid in your muscles begins to break down and be converted to carbon dioxide and water.
  • Question 4

What are two differences between anaerobic and aerobic respiration? 

 

Note that ATP is the name for the molecule in cells that carries energy.

 

 1

  ATP is released in both anaerobic and aerobic respiration

 2

 Less ATP is released in anaerobic respiration than in aerobic respiration

 3

 Carbon dioxide isn't produced in anaerobic respiration but is in aerobic respiration

 4

 Glucose is a reactant in aerobic and anaerobic respiration

CORRECT ANSWER
2 and 3
EDDIE SAYS
This is one of those questions that needs to be read carefully to avoid getting it wrong! All the four options are giving correct details about both sorts of respiration. 1 and 4 are similarities between aerobic and anaerobic respiration, since both types of respiration need glucose as a reactant and release energy. We were looking for differences, so the answer was options 2 and 3. More energy is released in aerobic respiration than in anaerobic, and also carbon dioxide is only a product in aerobic respiration.
  • Question 5

What is the name of X and Y in the equation below?

 

Image of anaerobic respiration equation

CORRECT ANSWER
EDDIE SAYS
This equation is a very important one to know, so take some time to learn it if you weren't too sure. There is only one reactant (glucose) and one product (lactic acid) in anaerobic respiration. Carbon dioxide and water are the two products of aerobic respiration.
  • Question 6

Lucy says the equation for anaerobic respiration in the human body is

glucose → lactic acid + ATP


Terri disagrees and says it's

glucose → carbon dioxide + ATP 

 

Who's correct?

 

CORRECT ANSWER
Lucy
EDDIE SAYS
Good job if you went with Lucy! In mammals, look out for lactic acid as a clue that anaerobic respiration is occurring. In fact, it is the only product of anaerobic respiration.
  • Question 7

 

Karl is at the gym exercising. After a while on the treadmill, he gets cramp in his legs.

 

What must he do to get rid of this cramp?

CORRECT ANSWER
Karl has to stop exercising and breathe hard to get rid of the lactic acid that has built up in his leg muscles
EDDIE SAYS
You might have opted for Karl to stop complaining and get on with it, but this was not the official correct answer! Anaerobic respiration is useful because it enables our bodies to release energy that is needed, even if we don't have enough oxygen. However, it does often cause pain because of the build-up of lactic acid in our muscles. To get rid of this pain, it is necessary to keep breathing hard (or pant) for a while after you stop exercising. This will get oxygen into your muscles which can then convert the painful lactic acid to harmless carbon dioxide and water.
  • Question 8

Why is less energy released from anaerobic respiration than during aerobic respiration?   

CORRECT ANSWER
The glucose molecules aren't fully broken down to release energy
EDDIE SAYS
How did you get on? In anaerobic respiration, less energy is released as glucose isn't broken down fully. Clearly, oxygen is needed to complete the breakdown.
  • Question 9

What do aerobic and anaerobic respiration have in common?

CORRECT ANSWER
Glucose is a reactant
Energy is released
EDDIE SAYS
So, there were two correct answers this time. The two forms of respiration are similar to each other because they both use glucose as a reactant. Their products are different, but they both release energy. Energy is pretty much the whole point of respiration, although the amount of energy differs depending on the type of respiration that occurs.
  • Question 10

John and George are doing laps around the playground for PE. George's legs start to hurt. He tells John that it's lactic acid building up in his muscles. John thinks that this is just an excuse to stop!

 

What do you think?

CORRECT ANSWER
George is correct, lactic acid is building up from anaerobic respiration
EDDIE SAYS
Well, you could probably say that all three options are correct here! They should both be concentrating on their running instead of complaining! Also, it is highly likely that George does want to stop if he is in pain! However, those two answers were just a bit of a joke and the correct one is option two. George is most likely to be in pain due to the build-up of lactic acid in his leg muscles. He needs to pant for a while to get rid of it and then he should feel able to do some more laps! How do you feel about this topic now? Hopefully, you are more confident than before you started the activity!
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