Respiration

Question 1

What is respiration?

Answer 1

The chemical reaction which releases the energy from glucose for cells to use.

Question 2

Where does aerobic respiration take place?

Answer 2

in the mitochondria of the cells

Question 3

What is the main difference between aerobic and anaerobic respiration?

Answer 3

Aerobic respiration uses oxygen and anaerobic does not.

Question 4

What is the word equation for aerobic respiration?

Answer 4

energy (out)
(
glucose + oxygen —> carbon dioxide + water

Question 5

What is the symbol equation for aerobic respiration?

Answer 5

energy (out)
(
C6H1206 + 6O2 —> 6CO2 + 6H20

Question 6

What type of reaction is aerobic respiration?

Answer 6

It is an oxidation reaction because it uses oxygen

Question 7

Respiration is an exothermic reaction, what does this mean?

Answer 7

It means that it gives out thermal (heat) energy.

Question 8

The energy released from respiration has two main functions- describe them.

Answer 8

1. Thermal energy to keep an organism warm- especially important for warm blooded creatures such as birds and mammals.
2. Chemical energy which can be stored or used for reaction and processes such as movement.

Question 9

What is the word equation for anaerobic respiration?

Answer 9

5% energy (out)
)
glucose ————————–> lactic acid

Question 10

When does our body get energy using anaerobic rather than aerobic respiration

Answer 10

During intense, heavy exercise such as sprinting our body cannot get enough oxygen to use aerobic respiration so it uses anaerobic instead.

Question 11

Lactic acid is a by product of anaerobic respiration, what effect does it have on the body?

Answer 11

Lactic acid causes muscle cramps and fatigue. This builds up in the muscles and stops it from working effectively, our body tells us to stop.

Question 12

Explain the term oxygen debt.

Answer 12

During anaerobic respiration lactic acid builds up in the muscles. Oxygen is needed to oxidise the lactic acid, the oxygen debt is the amount of oxygen needed to break down the lactic acid.

Question 13

Explain how the body repays oxygen debt.

Answer 13

1. After vigorous exercise the heart rate and breathing rate remain high for a few minutes in order to keep the muscles supplied with oxygen and glucose.
2. The lactic acid which has built up in the muscles from anaerobic respiration diffuses from a high concentration in the muscles to a lower concentration in the blood.
3. It then diffuses again from the higher concentration in the blood into the liver which has a lower concentration..
4. In the liver the lactic acid is oxidised back into glucose which diffuses back into the blood to be used in the body.

Question 14

Do plants respire anaerobically or aerobically?

Answer 14

Plants respire during the day during photosynthesis and also overnight.
They usually use aerobic respiration but sometimes use anaerobic if they do not have enough oxygen such as if their roots become waterlogged.

Question 15

Which organisms use anaerobic respiration as their main source of energy.

Answer 15

Yeasts use anaerobic respiration to produce energy.

                      energy (out)
                               )
     glucose --------------------> ethanol + carbon dioxide

Question 16

What is the name of the breakdown of glucose in yeasts?

Answer 16

It is called fermentation
The production of ethanol (alcohol) is used in brewing and the production of a range of alcoholic drinks.
The production of carbon dioxide is used in the baking of bread.

Question 17

How do we use fermentation commercially?

Answer 17

1. In the production of bread

2. In the production of alcoholic drinks

Question 18

What is metabolism?

Answer 18

It is the sum of all of the chemical reactions that occur in an organism.
it includes respiration, digestion & photosynthesis, ie all breakdown and synthesis reactions