B9.3- Anaerobic Respiration

Question 1

What is Anaerobic Respiration? (1)

Answer 1

= Anaerobic Respiration take place without oxygen

Question 2

What is Anaerobic Respiration? (2)

Answer 2

=less energy is released per molecule in anaerobic respiration because glucose is only partially broken down.

Question 3

Why can’t muscle cells continuously carry out aerobic respiration? Why do they revert to anaerobic respiration?

Answer 3

=When you exercise quite hard your heart may not be able to pump oxygenated blood to your respiring cells quickly enough to carry out aerobic respiration.
In the mean time, to still supply your body with energy your muscle cells can revert to anaerobic respiration, where glucose is broken down in the absence of oxygen.

Question 4

Do animals respire?

Answer 4

=Yes, When an animal cell is getting enough oxygen and glucose, it carries out aerobic respiration.

Question 5

What happens when the animal cell does not have the necessary oxygen to break down glucose molecules?
And where does this occur?

Answer 5

=When the animal cell does not have the necessary oxygen to break down glucose molecules, it has to carry out anaerobic respiration. This can occur in muscle cells during strenuous exercise.

Question 6

During which type of exercise do animals usually start to carry out anaerobic respiration?

Answer 6

= Intense of strenuous exercise.

Question 7

What is the generalised equation for anaerobic respiration?

Answer 7

=Glucose —–> Lactic Acid + Energy

Question 8

Is more or less energy released during anaerobic respiration?

Answer 8

=Less.

Question 9

What effect does lactic acid build up have on the muscles?

Answer 9

=Lactic acid build up in the muscles causes muscle fatigue, eventually this can lead to muscle cramps and the muscle stops working.

Question 10

How can lactic acid be cleared from the muscle?

Answer 10

=By an increase in oxygen concentration, replacing the oxygen debt by breathing more deeply.

Question 11

What is the word equation for anaerobic respiration in plants?

Answer 11

=Glucose ——> Ethanol + Carbon Dioxide + Energy

Question 12

What does the incomplete breakdown of glucose during anaerobic respiration produce?

Answer 12

=Lactic acid

Question 13

How is lactic acid produced?

Answer 13

=The incomplete breakdown of glucose during anaerobic respiration produces lactic acid.

Question 14

What can the build up of lactic acid cause?

Answer 14

=The build-up of lactic acid can cause fatigue, pain and cramping.

Question 15

What happens to the lactic acid after vigorous exercise?

Answer 15

=the body needs to remove lactic acid before it damages cells.

Question 16

Where is the lactic acid broken down ?

Answer 16

=Some lactic acid is broken down in the muscles. Some passes into the bloodstream and is taken to the liver to be broken down there.

Question 17

What is needed to break lactic acid?

Answer 17

=Oxygen

Question 18

What is lactic acid broken into?

Answer 18

=Water and carbon dioxide.

Question 19

What happens after strenuous exercise?

Answer 19

=an individual breathes heavily and maintains an elevated heart rate. This moves lactic acid to the liver and supplies liver and muscle cells with the necessary oxygen to break down lactic acid.

Question 20

Why do you need to continue breathing heavily after strenuous exercise?

Answer 20

= in order to repay the oxygen debt to your body. You will need to also use this oxygen to break down the lactic acid to avoid muscle cramps.

Question 21

What is oxygen debt?

Answer 21

=the amount of oxygen needed to break down lactic acid into carbon dioxide and water.

Question 22

What is the word equation with demonstrates how oxygen repayment occurs?

Answer 22

=Lactic acid + oxygen —-> carbon dioxide + water

Question 23

What are the differences between the breathing rate of a fit person and an unfit person?

Answer 23

=breathing rate of an unfit person increases more quickly than that of a fit person

Question 24

Do plants and some micro-organisms carry out anaerobic respiration?

Answer 24

=Yes if necessary.

Question 25

Where does anaerobic respiration take place in plants and some micro-organisms?

Answer 25

=waterlogged root cells or in bacteria infecting deep puncture wounds.

Question 26

Plant cells respiring anaerobically to produce?

Answer 26

=ethanol and carbon dioxide as well as energy.

Question 27

What do some microorganisms, such as bacteria used to make yoghurt, produce?

Answer 27

= They produce lactic acid via anaerobic respiration.

Question 28

Other microorganisms, like yeast, form what?

Answer 28

=Ethanol and carbon dioxide and energy this is known as fermentation.

Question 29

Respiring micro-organisms are used in the commercial production of many different products such as?

Answer 29

=Bread, alcohol and biofuels.

Question 30

What is the type of fungus in bread?

Answer 30

=Yeast

Question 31

What does (the fungus) yeast do during fermentation?

Answer 31

=Yeast digest the carbohydrates in the flour and releases carbon dioxide

Question 32

What does the carbon dioxide released in the bread fermentation process do?

Answer 32

=The carbon dioxide causes the bread to rise also creates gas pockets to give bread spongy texture.

Question 33

What happens (converts) during fermentation ?

Answer 33

=During fermentation, anaerobic respiration in the yeast cells converts the glucose into ethanol.

Question 34

Compare anaerobic respiration in a yeast cell with anaerobic respiration in an animal cell

Answer 34

• Yeast produces ethanol but muscles produce lactic acid
• Yeast produces carbon dioxide but muscles do not
• Both release small amounts of energy

Question 35

What does anaerobic respiration produce in animals?

Answer 35

=produces lactic acid in animals

Question 36

What does anaerobic respiration produce in plants?

Answer 36

=In plants produces ethanol and carbon dioxide.