B9 - Respiration

Question 1

What is cellular respiration?

Answer 1

An exothermic reaction that occurs continously in the mitochondria of living cells to supply the cells with energy.

Question 2

Respiration can take place aerobically and anaerobically. What’s the difference between the two?

Answer 2

Aerobic uses oxygen and anaerobic doesn’t use oxygen.

Question 3

What is the equation for aerobic respiration?

Answer 3

Glucose + oxygen -> Carbon dioxide + water
C₆H₁₂O₆ + 6O₂ -> 6CO₂ + 6H₂O

Question 4

What is the equation for anaerobic respiration?

Answer 4

Glucose -> Lactic acid
C₆H₁₂O₆ -> 2C₃H₆O₃

Question 5

Where does anaerobic respiration take place?

Answer 5

The muscles.

Question 6

What is anaerobic respiration in plant and yeast cells called?

Answer 6

Fermentation.

Question 7

What is fermentation represented by (in an equation)?

Answer 7

Glucose -> Ethanol + Carbon dioxide

Question 8

Explain the human body’s response to exercise.

Answer 8

• The muscles require more oxygenated blood
• To supply this, heart rate, breathing rate and breath intake all increase.
• If oxygen is insufficient, anaerobic respiration takes place leading to a build up of lactic acid
• During long periods of exercise, the muscles become fatigued and stop contracting efficiently.
• To rid the body of lactic acid, it must react with oxygen.

Question 9

What is oxygen debt?

Answer 9

The amount of oxygen needed to react with the lactic acid to remove it from the body.

Question 10

How is lactic acid removed?

Answer 10

• Lactic acid in the muscle
• Transported to the liver in the blood
• Converted back to glucose (through a reaction with oxygen)

Question 11

What is metabolism?

Answer 11

The sum of all reactions in a cell or the body.

Question 12

What do organisms need energy for?

Answer 12

• Reactions of respiration
• Reactions of photosynthesis
• Breakdown of excess proteins to form urea
• Conversion of glucose to starch, glycogen and cellulose.

Question 13

When all respiration reactions occur, what is released?

Answer 13

Energy.

Question 14

Why does anaerobic respiration take place in the muscles?

Answer 14

Because they need a lot of energy to contract. Energy is supplied through respiration. Sometimes, blood is not transported quick enough to transport enough oxygen to the muscles to allow the muscles to aerobically respirate.