Energy and Life

Energy Pyramids:

Autotrophs Characteristics: Use light energy from sun to produce food (convert sunlight energy to chemical energy) Requires chlorophyll Examples: plants, bacteria, some protozoa, algae

Heterotrophs Characteristics: Consume other organisms for energy source Examples: Animals, fungi, protists

Sun’s light energy Autotrophs: use pigments to absorb light energy and convert to chemical energy (unusable directly to cells) Heterotrophs and Autotrophs: convert chemical energy in food to cellular energy a cell can use

Adenosine Triphosphate ATP: the form of chemical energy that can be used directly by cells for functioning

ATP It’s an RNA nucleic acid with two extra phosphate groups

How ATP is used by cells:

How do plants make glucose needed by cells for ATP? In order for plant cells to make glucose that can be systematically broken down to make ATP, plant cells need a way to trap the sun’s light energy. They do this with the pigments they contain.

Pigments Q: What is their purpose? Answer: Give substances color Q: How do they function? Answer: They absorb or reflect light waves (energy). The reflected light waves are the ones we see. So, a red sweatshirt looks red because the pigments in the sweatshirt reflect red light waves and absorb all the others.

Q: Why do plants look green? Answer: Because they reflect the green light waves and absorb all the others.

Plant Pigments Two main types: 1. Chlorophyll (green and greenish-yellow) Chlorophyll a and chlorophyll b 2. Carotenoids (carotene; orange, red)

What happens in the fall? To conserve energy, plants lose their leaves by severing the connection between its branches and leaves. The first pigment to be broken down is chlorophyll. So, the other pigments can shine through.