4.3 Anaerobic and aerobic respiration

Question 1

Whats respiration

Answer 1

Respiration is the release of energy from sugar molecules such as glucose.

Question 2

Is respiration an exothermic or endothermic reaction?

Exothermic

Endothermic

justify your answer

Answer 2

Respiration is an exothermic reaction

because it involves the release of energy.

Question 3

Which process in plants produces the glucose required for respiration?

Answer 3

photosynthesis

Question 4

Give two examples of how cells use the energy from respiration.

Answer 4

To combine small molecules to make larger molecules

To break large molecules into smaller molecules

For muscle contraction

To maintain our body temperature

To move substances around the cell

Question 5

What is metabolism?

Answer 5

Metabolism is the set of chemical processes that occur within a living organism

Question 6

What is the word equation for aerobic respiration?

Answer 6

Glucose + Oxygen → Carbon dioxide + Water + Energy

Question 7

What is glucose converted to during anaerobic respiration in animals?

Answer 7

lactic acid.

Question 8

Complete the word equation for anaerobic respiration in plants and fungi:

Answer 8

Glucose → Ethanol + Carbon dioxide + Energy

Question 9

What are the two reasons animals cells prefer aerobic respiration to anaerobic respiration?

Answer 9

It produces much more energy (ATP) per glucose molecule.

It doesn’t produce harmful byproducts like lactic acid, which can cause muscle fatigue.

Question 10

Where does aerobic respiration occur in a cell?

Answer 10

mitochondria

Question 11

Where does anaerobic respiration occur in a cell?

Answer 11

cytoplasm

Question 12

Aerobic is respiration _____ the presence of oxygen

Answer 12

with

Question 13

Anaerobic is respiration _____ the presence of oxygen

Answer 13

without

Question 14

Why do we prefer not to use anaerobic resp?

Answer 14

1) glucose is only partially broken down which makes it inefficient as we are not unlocking all the energy in it

2) causes muscle fatigue because lactic acid is produced, its toxic

Question 15

Word equation of anerobic respiration

Answer 15

Glucose —> lactic acid + energy

Question 16

How does the liver break down
lactic acid?

Answer 16

Lactic acid is produced in muscles during anaerobic respiration (when there’s not enough oxygen).

Lactic acid enters the bloodstream and is transported to the liver.

In the liver, lactic acid is converted into simpler substance

that can be used to make sugar as it cannot be changed directly into it.

Pyruvate ( the simpler sub ) is then used to make glucose through a process called gluconeogenesis.

The new glucose can either be stored in the liver or sent back to the muscles for energy use.

This process helps stop lactic acid from building up and keeps your muscles energized.