Topic 2 - Respiration

Question 1

What does aerobic respiration have that anaerobic respiration (in animals) doesn’t?

Answer 1

Oxygen

Question 2

How much of the energy transferred is needed for living processes?

Answer 2

The energy transferred supplies all the energy needed for living processes.

Question 3

How can respiration in cells take place?

Answer 3

Respiration in cells can take place aerobically (using oxygen) or anaerobically (without oxygen) to transfer energy.

Question 4

Where does aerobic respiration take place?

Answer 4

Aerobic respiration takes place in the mitochondria

Question 5

What do organisms need energy for?

Answer 5

• chemical reactions to build larger molecules
• movement
• keeping warm.

Question 6

What equation does this represent: glucose + oxygen → carbon dioxide + water + energy release

Answer 6

Aerobic respiration

Question 7

What is the chemical symbol for Glucose?

Answer 7

C6H12O6

Question 8

What is the chemical symbol for Carbon Dioxide?

Answer 8

CO2

Question 9

What is the chemical symbol for Oxygen?

Answer 9

O2

Question 10

What is the chemical symbol for Water?

Answer 10

H2O

Question 11

What is the equation for anaerobic respiration in muscle?

Answer 11

Anaerobic respiration in muscles is represented by the equation:
Glucose → lactic acid.

Question 12

Why is there less energy transferred in anaerobic respiration?

Answer 12

As the oxidation of glucose is incomplete in anaerobic respiration much less energy is transferred than in aerobic respiration.

Question 13

What is the equation for anaerobic respiration in plants and yeast?

Answer 13

Anaerobic respiration in plant and yeast cells is represented by the equation:
glucose → ethanol + carbon dioxide + energy release

Question 14

Why does the heart rate, breathing rate and breath volume increase during exercise? And what does this enable?

Answer 14

The heart rate, breathing rate and breath volume increase during exercise to supply the muscles with more oxygenated blood. This enables increased cellular respiration so more energy is transferred to met the demands of the muscle cells.

Question 15

What causes oxygen debt? How does this affect the muscles?

Answer 15

If insufficient oxygen is supplied anaerobic respiration takes place in muscles. The incomplete oxidation of glucose causes a build-up of lactic acid and creates an oxygen debt. During long periods of vigorous activity muscles become fatigued and stop contracting efficiently.

Question 16

What is oxygen debt?

Answer 16

Oxygen debt is the amount of extra oxygen the body needs after exercise to react with the accumulated lactic acid and remove it from the cells.

Question 17

What happens to lactic acid?

Answer 17

Blood flowing through the muscles transports the lactic acid to the liver where it is converted back into glucose.

Question 18

Compare the processes of aerobic and anaerobic respiration with regard to the need for oxygen, the differing products and the relative amounts of energy transferred.

Answer 18

Aerobic and anaerobic respiration are two different pathways of cellular respiration used by living organisms to generate energy from food molecules.

Aerobic respiration occurs in the presence of oxygen, while anaerobic respiration occurs in the absence of oxygen.

Need for Oxygen:
In aerobic respiration, oxygen is required as the final electron acceptor in the electron transport chain. In contrast, anaerobic respiration does not require oxygen as the final electron acceptor, instead, other inorganic molecules such as sulfate, nitrate or carbon dioxide may serve as electron acceptors.

Differing Products:
The final products of aerobic respiration are carbon dioxide, water, and a large amount of ATP (Adenosine triphosphate). In contrast, the final products of anaerobic respiration vary depending on the type of organism and the electron acceptor used, but may include lactic acid, ethanol, or other organic molecules.

Overall, aerobic respiration is a more efficient process for generating energy from food molecules as it produces more ATP per glucose molecule than anaerobic respiration.