4. Bioenergetics

What is the word equation for photosynthesis?

Carbon dioxide + water → (light) → glucose + oxygen

What type of reaction is photosynthesis?

Endothermic (energy absorbed by chloroplasts from light)

Name four factors that affect the rate of photosynthesis.

Temperature, light intensity, carbon dioxide concentration, amount of chlorophyll

What is a limiting factor in photosynthesis?

A factor that slows the rate of photosynthesis when in short supply

What is the purpose of the pondweed practical?

To investigate the effect of light intensity on the rate of photosynthesis

List five uses of glucose produced in photosynthesis.

Respiration, starch storage, fat/oil storage, cellulose production, amino acids for protein synthesis

What type of reaction is cellular respiration?

Exothermic (energy released continuously in cells)

Write the word equation for aerobic respiration.

Glucose + oxygen → carbon dioxide + water

What is the word equation for anaerobic respiration in muscles?

Glucose → lactic acid

Why does anaerobic respiration release less energy than aerobic respiration?

Because glucose is only partially broken down (incomplete oxidation)

What is the word equation for anaerobic respiration in yeast?

Glucose → ethanol + carbon dioxide

Why is fermentation in yeast economically important?

It is used in the manufacture of bread and alcoholic drinks

How does the body respond to exercise in terms of respiration?

Heart rate, breathing rate, and breath volume increase to supply muscles with more oxygen

What causes oxygen debt after exercise?

Lactic acid build-up from anaerobic respiration that needs oxygen to be broken down

What is metabolism?

The sum of all chemical reactions in the body

Name some metabolic processes involving glucose.

Conversion to starch, glycogen, cellulose; formation of lipids from glycerol and fatty acids; synthesis of amino acids and proteins; respiration; protein breakdown to urea

What is the inverse square law in relation to photosynthesis?

Light intensity decreases with the square of the distance from the light source, affecting photosynthesis rate