ENERGY

Energy in Living Things The immediate source of energy for living things is adenosine triphosphate (ATP).

Structure of ATP An adenine molecule is bonded to ribose which is bonded to 3 phosphate groups.

Adenosine Triphosphate

The bonds holding the phosphate groups together can be broken and releases energy. An ATP that loses 1 phosphate group is called adenosine diphosphate (ADP).

With the addition of energy to ADP and an available phosphate group, ADP can reform ATP.

ATP – ADP CYCLE

ENERGY FLOW IN LIVING THINGS

Plants and algae use the sun’s energy during photosynthesis to make glucose (sugar)

Living things use the stored energy from glucose to make ATP during cellular respiration

How does energy flow in ecosystems?

A food chain is how energy moves through populations in an ecosystem

The first trophic level is the producer (autotrophs)

The second trophic level is primary consumers (heterotrophs); primary consumers are often herbivores

The third trophic level is secondary consumers; usually carnivores

The fourth trophic level (if there is one) is the tertiary level; also usually carnivores

The fifth trophic level (rare) is the quaternary level

SOME CONSUMERS ARE OMNIVORES!!!

Some heterotrophs decompose dead organisms, returning the nutrients to soil, water and air; they’re detritivores or decomposers (fungi for example live on dead matter, secrete digestive enzymes on it, and absorb the digested molecules)

A food web is many interconnected food chains

Ecology pyramids are models to show how energy flows through ecosystems

Pyramids can also show numbers of individuals in each populations

A biomass pyramid represents the total mass of living matter at each trophic level