Unit 1 - Key Area 6 - Respiration

Question 1

What is aerobic respiration?

Answer 1

The chemical energy stored in glucose must be released by all cells through a series of enzyme-controlled reactions called respiration

Question 2

What is the word equation for aerobic respiration?

Answer 2

Glucose + Oxygen –> Carbon dioxide + Water + energy (ATP)

Question 3

What is the energy released from the breakdown of glucose used for?

Answer 3

Used to generate ATP. The energy transferred by ATP can be used for cellular activities.

Question 4

What cellular activities use energy transferred by ATP?

Answer 4

Muscle Contraction

Cell Division

Protein Synthesis

Transmission of Nerve impulses

Active Transport

Question 5

Describe the breakdown of glucose

Answer 5

Glucose is broken down into 2 molecules of pyruvate releasing enough energy to yield 2 molecules of ATP

Question 6

Describe aerobic respiration

Answer 6

If oxygen is present, aerobic respiration takes place. Each pyruvate molecule is broken down to carbon dioxide and water releasing enough energy to yield a large number of ATP.

Question 7

Describe fermentation in different cells

Answer 7

In absence of oxygen the fermentation pathway takes place.

In animal cells the pyruvate molecules are converted to lactate:
Pyruvate –> Lactate + Energy (no ATP)

In plant and yeast cells, they are converted to carbon dioxide and ethanol:
Pyruvate –> Carbon dioxide + ethanol + energy (no ATP)
The fermentation pathway yields only the initial 2 molecules of ATP.

Question 8

Where does each stage of respiration take place?

Answer 8

Respiration begins in the cytoplasm. The process of fermentation is completed in the cytoplasm.
The process of aerobic respiration is completed in the mitochondria.
Cells which require a lot of energy have many mitochondria.

Question 9

Is oxygen required in fermentation?

Answer 9

No

Question 10

Where does fermentation take place?

Answer 10

Cytoplasm

Question 11

Does fermentation breakdown glucose?

Answer 11

Partial breakdown

Question 12

Is energy produced in fermentation?

Answer 12

A small amount (from initial 2 ATP molecules).

Question 13

What are the end products of fermentation in an animal cell?

Answer 13

Lactate

Question 14

What are the end products of fermentation in plant and yeast cells?

Answer 14

Carbon dioxide and ethanol

Question 15

Is oxygen required in aerobic respiration?

Answer 15

Yes

Question 16

Where does aerobic respiration take place?

Answer 16

Stage 1 - Cytoplasm

Stage 2 - Mitochondria

Question 17

Does aerobic respiration breakdown glucose?

Answer 17

Complete breakdown

Question 18

Is energy produced in aerobic respiration?

Answer 18

Large amount

Question 19

What are the end products of aerobic respiration in an animal cell?

Answer 19

Carbon dioxide + water

Question 20

What are the end products of aerobic respiration in plant and yeast cells?

Answer 20

Carbon dioxide and water

Question 21

What is a respirometer and how is it used?

Answer 21

A respirometer measures the rate of respiration in a small organism (living thing)

The organism will use up oxygen during respiration, reducing the pressure and making the coloured liquid move up the tube.

The distance the liquid moves up the tube during a certain period of time gives a measurement of the respiration rate of the organism.

A control is set up as a comparison to the organism being investigated. It will have a non-living substance instead.

The experiment is repeated and an average is taken to obtain reliable results.

Question 22

What does ATP stand for?

Answer 22

Adenosine triphosphate

Question 23

What does ADP + P stand for?

Answer 23

Adenosine diphosphate + phosphate