B4: Bioenergetics

Question 1

What is the word equation for photosynthesis?

Answer 1

Carbon Dioxide + Water > Glucose + Oxygen

Question 2

What is the balanced symbol equation for photosynthesis?

Answer 2

6CO2 + 6H2O > C6H12O6 + 602

Question 3

Why is photosynthesis important for the survival of plants?

Answer 3

Because it allows plants to produce glucose, which can be broken down in respiration into energy needed for processes such as protein synthesis and cell division.

Question 4

Why should plants be de-starched before photosynthesis experiments?

Answer 4

So you know that any starch present at the end of the experiment has been produced during the experiment.

Question 5

How do you de-starch a plant?

Answer 5

By placing it in the dark for 48 hours.

Question 6

How do you find out if a leaf contains starch?

Answer 6

Using an iodine starch test. (See RPA)

Question 7

What are the limiting factors of photosynthesis?

Answer 7

• Low temperature.
• Shortage of CO2.
• Shortage of light.
• Shortage of chlorophyll.

Question 8

What are the 4 ways in which conditions of a greenhouse can be optimised for plant growth?

Answer 8

To create the optimum conditions for photosynthesis,
- The temperature can be controlled with heaters (expensive).
- The amount of carbon dioxide can be monitored.
- The amount of light can be controlled using UV lamps.
- The amount of chlorophyll can be increased by using nutrient-rich soil.

Question 9

What are the benefits of artificially manipulating plant growth?

Answer 9

Faster growth and increased yield lead to more profit.

Question 10

What is the glucose produced in photosynthesis used for?

Answer 10

• Respiration.
• Converted into starch for storage.
• To produce cellulose to strengthen cell walls.
• To produce amino acids for protein synthesis.

Question 11

What are nitrates used for in plants?

Answer 11

To make proteins.

Question 12

Food tests: what solution is used to test for starch?

Answer 12

Iodine Solution.

Question 13

Food tests: what solution is used to test for protein?

Answer 13

Buiret Solution.

Question 14

Food tests: what solution is used to test for sugars?

Answer 14

Benedict’s Solution.

Question 15

What is the word equation for aerobic respiration in animals?

Answer 15

Glucose + Oxygen > Carbon Dioxide + Water.

Question 16

What is the balanced symbol equation for aerobic respiration in animals?

Answer 16

C6H12O6 + 6O2 → 6CO2 + 6H2O.

Question 17

Is respiration an endothermic or exothermic reaction?

Answer 17

Exothermic. (Releases energy)

Question 18

Is photosynthesis an endothermic or exothermic reaction?

Answer 18

Endothermic. (Takes IN light energy)

Question 19

What is aerobic respiration?

Answer 19

Respiration using sufficient oxygen.

Question 20

What 3 things do organisms need the energy from respiration for?

Answer 20

• Chemical reactions.
• Movement.
• Keeping warm.

Question 21

What is anaerobic respiration?

Answer 21

Respiration using insufficient oxygen.

Question 22

What is the word equation for anaerobic respiration in animals?

Answer 22

Glucose > Lactic Acid.

Question 23

What is the balanced symbol equation for anaerobic respiration in animals?

Answer 23

C6H12O6 > 2C3H6O3.

Question 24

What are the products of anaerobic respiration in animals vs plants/yeast?

Answer 24

Animals: Lactic Acid.
Plants/Yeast: Ethanol + Carbon Dioxide.

Question 25

What are the consequences of anaerobic respiration?

Answer 25

Much less energy is released than aerobic respiration.

Question 26

What is the word equation for anaerobic respiration in plants/yeast cells?

Answer 26

Glucose > Ethanol + Carbon Dioxide.

Question 27

What is the balanced symbol equation for anaerobic respiration in plants/yeast cells?

Answer 27

C6H12O6 > 2C2H5OH + 2CO2

Question 28

What is anaerobic respiration in yeast cells called?

Answer 28

Fermentation.

Question 29

Which industries is fermentation used in?

Answer 29

The manufacture of bread and alcoholic drinks.

Question 30

Why is anaerobic respiration of yeast used to make bread and alcoholic drinks?

Answer 30

- The bubbles of carbon dioxide produced make bread rise. - The ethanol produced creates alcohols.

Question 31

What happens to heart and breathing rates during exercise?

Answer 31

They increase.

Question 32

Why do heart and breathing rates increase during exercise?

Answer 32

To supply oxygen to muscle cells faster.

Question 33

What happens when there isn't enough oxygen in the muscles?

Answer 33

They respire anaerobically and produce lactic acid.

Question 34

What is oxygen debt?

Answer 34

The amount of oxygen needed to oxidise the lactic acid in the body.

Question 35

What happens to breath volume during exercise?

Answer 35

It increases.

Question 36

How does the body get rid of lactic acid?

Answer 36

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

Question 37

What does lactic acid cause in muscles?

Answer 37

Muscle fatigue.

Question 38

What is metabolism?

Answer 38

The rate of chemical reactions in the body.

Question 39

Give 3 examples of metabolic reactions in the body.

Answer 39

the conversion of glucose to starch, glycogen and cellulose the formation of lipids the formation of amino-acids and proteins respiration the breakdown of excess proteins to form urea for excretion.

Question 40

Describe the formation of urea.

Answer 40

Urea is produced from the breakdown of excess protein/amino acids in the liver.

Question 41

What are glucose and nitrate ions used to do in animals?

Answer 41

Create amino acids that are used to make proteins.