B4-Bioenergetics

Question 1

What type of reaction is photosynthesis?

Answer 1

An endothermic reaction-requires energy

Question 2

What is the word and symbol equation for photosynthesis?

Answer 2

Carbon dioxide + Water (+light ) –> Glucose + Oxgyen
6CO₂ + 6H₂O (+light ) –>C₆H₁₂0₆ + 6O₂

Question 3

What factors affect the rate of photosynthesis?

Answer 3

• Increase light intensity = increased photosynthesis
• Increased temperature = increased photosynthesis up to a point until the enzymes become denatured
• Increased carbon dioxide concentration = increased photosynthesis

Question 4

How does light intensity relate to the distance from light?

Answer 4

Light intensity∝1/distance²

Question 5

What does ∝ mean

Answer 5

Proportional to

Question 6

What are the uses of glucose in plants?

Answer 6

• For storage-fats, oils or starch
• To produce cellulose for the cell walls
• To create amino acids
• For respiration

Question 7

What are limiting factors in respiration?

Answer 7

Factors such as light intensity, temperature or carbon dioxide concentration that limit the rate of respiration

Question 8

What type of reaction is respiration?

Answer 8

Exothermic-releases energy

Question 9

What is the word and symbol equation for aerobic respiration?

Answer 9

Glucose + Oxgyen –> Carbon dioxide + Water (+energy )
C₆H₁₂0₆ + 6O₂ –> 6CO₂ + 6H₂O (+energy )

Question 10

Where does respiration take place?

Answer 10

The mitochondria

Question 11

Why is respiration needed?

Answer 11

• So living cells can carry out basic functions
• So muscles can work
• To regulate internal body temperatures in the body
• For active transport

Question 12

What is anaerobic respiration?

Answer 12

Respiring without oxygen

Question 13

What is the word equation for anaerobic respiration in humans?

Answer 13

glucose–>lactic acid (+energy )

Question 14

How many times less efficient is anaerobic respiration than aerobic respiration?

Answer 14

19 times
2 compared to 38 units of atp

Question 15

What is the word equation for anaerobic respiration in plants?

Answer 15

glucose –> ethanol + carbon dioxide (+energy )

Question 16

What is the body’s response to exersise? (6)

Answer 16

• An increase in heart rate
• Glycogen stores in mucles are depleted
• Lactic acid levels build up
• The flow of oxygenated blood to the muscles increases
• Breathing rate increases
• Sweat for cooling down the body

Question 17

What does the build up of lactic acid produce?

Answer 17

Oxygen debt

Question 18

What is oxygen debt?

Answer 18

When lactic acid is taken directly to the liver by the blood and is either oxidised into carbon dioxide and water or converted to glucose then glycogen-this requires oxygen.

Question 19

What is metabolism?

Answer 19

The sum of all chemical reactions in the body

Question 20

What does metabolism include? (What are some of the reactions that take place?)

Answer 20

• The conversion of glucose to starch, glycogen and cellulose
• The formation of lipid molecules
• The use of glucose and nitrate ions to form amino acids
• The breakdown of excess proteins to form urea