ENERGY FOR LIFE

Trapping and Using Energy

Metabolism The total of all chemical reactions in an

organism The chemical reactions of metabolism need

enzymes Enzymes help cause the chemical reaction to

take place The enzyme is not changed by the chemical

reaction Enzymes are reusable

Photosynthesis

Producers Organisms that can produce their own food Use the energy from sunlight to produce

sugar Usually green organisms (contain

chlorophyll) Consumers

Organisms that cannot produce their own food

Photosynthesis

Energy from the sun is used to drive chemical reactions to produce sugar

carbon dioxide + water sugar + oxygen (raw materials) (enzymes)

(products)

In plants, the raw materials come from the soil and air.

Storing Carbohydrates

Plants make more sugar during photosynthesis than they can use at the time. Changed into starch and stored Used to make other types of

carbohydrates

Carbohydrates

Plants use carbohydrates for: Growth Maintenance Reproduction

Consumers

Why is photosynthesis important to consumers? Consumers take in food by eating

producers or other consumers Photosynthesis is involved directly

or indirectly in producing food for consumers

Respiration

Chemical reactions that break down food into simpler substances that can be used by the cell

Uses oxygen to break down the food Stored energy is released when the food

is broken down Enzymes are needed for respiration Occurs in all living cells

Breaking Down Carbohydrates Carbohydrates are the easiest food to

break down Respiration takes place in the cytoplasm

of the cell Carbohydrates are broken down

into glucose molecules Glucose is further broken down into

simpler substances

Breaking Down Carbohydrates Those simpler substances are then

transported to the mitochondria Those substances are further

broken down More energy is released Produces carbon dioxide and water

as waste products

Fermentation

Takes place when there is not enough oxygen for respiration to occur

Chemical reactions occur in the cytoplasm only

Produces some energy and waste products Lactic acid Alcohol Carbon dioxide

Fermentation

Some microorganisms use fermentation Produce yogurt Some cheeses

Yeasts Breaks down sugar in bread

Carbon dioxide (makes the bread dough rise)

Alcohol

Related Processes

Comparing photosynthesis and respiration/fermentation What is produced in one process is

used in the other process to produce energy

The two processes are almost opposite of each other

Related Processes

Photosynthesis Produces sugar and oxygen These products used in respiration

Respiration Produces carbon dioxide and water These products used in

photosynthesis