B4 - Respiration

Question 1

Where does energy come from?

Answer 1

Food

Question 2

How is energy from food transferred?

Answer 2

By respiration

Question 3

What is respiration?

Answer 3

The process of transferring energy from the breakdown of glucose

Question 4

How do plants get glucose?

Answer 4

They make it through photosynthesis.

Question 5

How do animals produce glucose?

Answer 5

By breaking down the biomass they get when they eat other organisms

Question 6

What do organisms need to survive?

Answer 6

The energy transferred by respiration.

Question 7

How frequently does respiration happen?

Answer 7

Continuously in every cell in all living organisms.

Question 8

What happens to the energy transferred from respiration?

Answer 8

The energy transferred form respiration can’t be used directly by cells.

So it is used to make a substance called ATP

Question 9

What does ATP do?

Answer 9

It stores the energy needed for essential processes

Question 10

What essential processes does ATP store energy for?3

Answer 10

Breaking and making molecules
Active transport
Contracting muscles

Question 11

What controls the chemical reactions in cellular respiration?

Answer 11

Enzymes

The overall rate of respiration is affected by both temperature and pH

Question 12

Is cellular respiration endothermic or exothermic?

Answer 12

Exothermic - it transfers energy to the environment by heat

Question 13

What do cells use as a substrate in respiration?

Answer 13

Glucose

But organisms can break down other organic molecules to use as substrates for respiration such as other carbohydrates, proteins and lipids.

Question 14

Name the two types of respiration

Answer 14

Aerobic

Anaerobic

Question 15

What is needed for aerobic respiration to happen?

Answer 15

Plenty of oxygen

Question 16

Which is the most efficient way to transfer energy from glucose?

Answer 16

Aerobic respiration

Question 17

What happens in aerobic respiration?

Answer 17

Breaks down glucose and combines the products with oxygen to make carbon dioxide (a waste product) and water.

Question 18

What is a waste product of aerobic respiration?

Answer 18

Carbon dioxide

Question 19

How much ATP is produced by aerobic respiration?

Answer 19

32 molecules per molecule of glucose.

Question 20

Equation for aerobic respiration

Answer 20

Glucose + oxygen. —>carbon dioxide +water

C6 H12 O6 + 6O2 -> 6CO2 + 6H2O

Question 21

Where does aerobic respiration mostly take place in eukaryotic cells?

Answer 21

In subcellular structure called mitochondria

Question 22

Why does most aerobic respiration in eukaryotic cells take place in the mitochondria?

Answer 22

The mitochondria contains most of the enzymes needed to control aerobic respiration reactions.

Question 23

Where does aerobic respiration take place in prokaryotic cells?

Answer 23

In the cytoplasm

Question 24

What does anaerobic mean?

Answer 24

Without oxygen

Question 25

How much ATP is produced in anaerobic respiration?

Answer 25

2 molecules

Question 26

Where does anaerobic respiration take place ?

Answer 26

In the cytoplasm

Question 27

Explain why anaerobic respiration happens in human cells during vigorous exercise.

Answer 27

Your body can’t supply enough oxygen to your muscles cells for aerobic respiration so they have to start respiring anaerobically as well.

Question 28

Explain why anaerobic respiration happens in plant root cells, in waterlogged soil.

Answer 28

If the soil is water logged there will be no oxygen available for the roots, so the root cells will have to respire anaerobically

Question 29

Explain why anaerobic respiration happens in bacterial cells when they enter a puncture wound.

Answer 29

Bacteria get under your skin through puncture wounds and there is very little oxygen under the skin, so only bacteria that respire anaerobically can survive there.

Question 30

What is lactic acid?

Answer 30

During anaerobic respiration, glucose is only partially broken down and lactic acid is formed as a waste product.

Question 31

Lactic acid is formed as a waste product from anaerobic respiration in what organism?

Answer 31

Animals and some bacteria

Question 32

What do plants and some microorganisms produce instead of lactic acid?

Answer 32

Ethanol and carbon dioxide.

Question 33

Comparing aerobic and anaerobic respiration -conditions

Answer 33

Aerobic - oxygen present Anaerobic - not enough oxygen present (eg during vigorously exercise, in water logged soils)

Question 34

Comparing aerobic and anaerobic respiration - inputs

Answer 34

Aerobic - glucose (or another organic molecule) and oxygen Anaerobic - glucose (or another organic molecule)

Question 35

Comparing aerobic and anaerobic respiration - outputs

Answer 35

Aerobic - carbon dioxide and water Anaerobic - lactic acid (animals and some bacteria) Ethanol and carbon dioxide (plants and some microorganisms such as yeast)

Question 36

Comparing aerobic and anaerobic respiration - ATP yield

Answer 36

Aerobic - high 32ATP made per molecule of glucose Anaerobic - lower 2ATP mad3 per molecule of glucose

Question 37

Name the product(s) of anaerobic respiration in plants. (1 mark)

Answer 37

Ethanol and carbon dioxide

Question 38

Why is it advantageous for organisms to respire aerobically rather than anaerobically?

Answer 38

Aerobic respiration produces much more ATP than anaerobic respiration