Module 4 Bioenergetics

Photosynthesis

process by which plants make glucose using light energy

Word equation for photosynthesis

carbon dioxide + water → glucose + oxygen

Balanced equation for photosynthesis

6CO2 + 6H2O → C6H12O6 + 6O2

Chloroplast

organelle where photosynthesis takes place

Chlorophyll

green pigment that absorbs light energy

Light energy role

provides energy to convert carbon dioxide and water into glucose

Rate of photosynthesis

speed at which photosynthesis occurs

Limiting factor

factor that stops the rate of photosynthesis increasing

Limiting factors of photosynthesis

light intensity carbon dioxide temperature

Light intensity effect

increases rate of photosynthesis up to a maximum

Carbon dioxide effect

higher concentration increases photosynthesis rate

Temperature effect

increases rate up to optimum then enzymes denature

Greenhouse effect in plants

keeps temperature and CO2 levels high for growth

Greenhouse benefits

allows controlled conditions for maximum photosynthesis

Uses of glucose in plants

respiration, growth, storage as starch or cellulose

Starch function

energy storage in plants

Cellulose function

makes cell walls for support

Glucose for respiration

releases energy in cells

Limiting factor graph

shows how one factor limits rate of photosynthesis

Inverse square law (light)

light intensity decreases with distance from light source

Aerobic respiration

breakdown of glucose using oxygen to release energy

Word equation for aerobic respiration

glucose + oxygen → carbon dioxide + water

Balanced equation for respiration

C6H12O6 + 6O2 → 6CO2 + 6H2O

Site of respiration

mitochondria

Energy release in respiration

used for movement growth and active transport

Respiration in animals

continuous process in all living cells

Anaerobic respiration in muscles

occurs when oxygen is low during exercise

Lactic acid production

product of anaerobic respiration in animals

Oxygen debt

extra oxygen needed to break down lactic acid after exercise

Anaerobic respiration in yeast

produces ethanol and carbon dioxide

Fermentation

process of anaerobic respiration in yeast

Word equation yeast anaerobic respiration

glucose → ethanol + carbon dioxide

Oxygen debt recovery

deep breathing after exercise to repay oxygen debt

Effect of exercise on respiration

increases rate to supply more energy

Metabolism

sum of all chemical reactions in a cell or body

Energy use in body

movement maintaining temperature growth and repair

Homeostasis link

respiration provides energy for body regulation

Respiration comparison

aerobic releases more energy than anaerobic

Muscle fatigue

caused by build-up of lactic acid during intense exercise

Importance of oxygen

allows complete breakdown of glucose for maximum energy

ATP

energy currency used in cells (produced during respiration)