B1.3 - Respiration

Question 1

What is meant by the term metabolic rate?

Answer 1

The speed in which chemical reactions in your cells transfer energy from its chemical stores in food

Question 2

what is the use of vitamins and minerals in the body?

Answer 2

A variety of roles - mainly to maintain overall good health

Ie. Maintain heartbeat, build strong boned, transmit nerve impulses

Question 3

Explain the importance of sugars in:

(a) the body

Answer 3

(a) they provide the body with energy

Question 4

Explain the importance of animo acids in the synthesis of proteins

Answer 4

animo acid monomers join together to make protein polymers

Question 5

when fungi respire anaerobically is it

• exothermic
• or endothermic

Answer 5

exothermic

Question 6

What enzyme breaks down carbohydrates?

Answer 6

carbohydrase

starch = amylase

Question 7

What determines the protein that is synthesised?

Answer 7

The order in which animo acids are joined together

Question 8

what enzyme breaks down protein molecules?

Answer 8

protease

Question 9

what enzyme breaks down lipid molecules?

Answer 9

lipase

Question 10

once food molecules are fully digested, what happens to them?

Answer 10

1) they are absorbed into your bloodstream

2) and then travel to the cells that need them

Question 11

state the word equation for aerobic respiration

Answer 11

oxygen + glucose ——> carbon dioxide + water

Question 12

state the chemical equation for aerobic respiration

Answer 12

C6H12O6 + 602 -> 6CO2 + 6H20

Question 13

why does aerobic respiration occur?

Answer 13

To react glucose with oxygen so energy can be released (or stored as ATP)

Question 14

What is ATP?

Answer 14

• Adenosine Triphosphate

- a chemical energy store in the body

Question 15

How is ATP used once produced during respiration? (3)

Answer 15

• to synthesise larger molecules from smaller ones (to make new cell material) - ie. larger substrates
• for movement
  ie. animals use ATP to contract muscle cells
• to stay warm
  ie. an increased rate of reaction allows more energy by heating (keep body warm)

Question 16

Where does respiration occur?

Answer 16

In the mitochondria of a cell

Question 17

what does the number of mitochondria in a cell show, and what does it mean for muscle cells?

Answer 17

how active the cell is

Since muscle cells have a lot of mitochondria, it means they are very active (as they contract very often and so have to transfer a lot of energy)

Question 18

how are mitochondria adapted to efficiently respire?

Answer 18

• they have folded inner membrane which gives a large surface area

Question 19

state the word equation for anaerobic respiration in animals

Answer 19

glucose —-> lactic acid

Question 20

state the word equation for anaerobic respiration in plants and bacteria

Answer 20

glucose ——> ethanol + carbon dioxide

Question 21

State one advantage of respiring aerobically compared to anaerobically

Answer 21

more ATP is produced during anaerobic respiration

Question 22

State one disadvantage of respiring anaerobically

Answer 22

lactic acid is produced - which causes pain and stops the muscle from contracting (known as fatigue)

Question 23

what is oxygen debt?

Answer 23

when extra oxygen inhaled is required to break down lactic acid (produced by anaerobic respiration)

Question 24

state one similarity and three difference between anaerobic respiration in plants and in animals

Answer 24

• both have glucose as a reactant
• Plants do not produce lactic acid, they produce ethanol
  or
• plants produce carbon dioxide as a product, animals do not in anaerobic respiration
  or
• buildup of ethanol can kill plants, build up of lactic acid cannot kill animals (only muscle cramps)

Question 25

state the difference between a monomer and a polymer

Answer 25

a monomer is made from single units and a polymer is made from multiple bonded units

Question 26

how many more molecules of ATP are produced by aerobic respiration compared to anaerobic respiration?

Answer 26

36

Question 27

Is cellular respiration exothermic or endothermic?

and why

Answer 27

Exothermic

- body heats up by itself (as respiration is constantly occurring)

Question 27

Give an example of anaerobic respiration in plants/bacteria

Answer 27

• fermentation

- yeast blooming