Photosynthesis…it doesn’t involve taking photo All cells need energy to carry out their functions such as making proteins and transporting substances into and out of the cell. All cells need energy to carry out their functions such as making proteins and transporting substances into and out of the cell. Photosynthesis—the process by which a cell captures energy in sunlight and uses it to make food. Photosynthesis—the process by which a cell captures energy in sunlight and uses it to make food. Photo—Greek for “light” and syntithenai means “putting together” Photo—Greek for “light” and syntithenai means “putting together”

More Photosynthesis Nearly all living things obtain energy either directly or indirectly from the energy of sunlight that is captured during photosynthesis. Nearly all living things obtain energy either directly or indirectly from the energy of sunlight that is captured during photosynthesis. – This happens due to the food chain

Producers & Consumers Autotroph (producer)—an organism that makes its own food Autotroph (producer)—an organism that makes its own food – i.e. plants Heterotroph (consumer)—an organism that can’t make it’s own food Heterotroph (consumer)—an organism that can’t make it’s own food – i.e. zebras lions, humans They eat other organisms (some absorb food from other organisms (fungi)) They eat other organisms (some absorb food from other organisms (fungi))

The Process of Photosyn. During photosynthesis, plants and some other organisms absorb energy from the sun and use the energy to convert carbon dioxide and water into sugars and oxygen During photosynthesis, plants and some other organisms absorb energy from the sun and use the energy to convert carbon dioxide and water into sugars and oxygen – Happens in two stages Stage 1 (capturing energy) Stage 1 (capturing energy) – Captures energy from the sunlight in the leaves – Chlorophyll—the main pigment for photosynthesis in chloroplasts Think of solar cells in a solar-powered calculator Think of solar cells in a solar-powered calculator water in chloroplasts is split into hydrogen and oxygen water in chloroplasts is split into hydrogen and oxygen – Oxygen is a waste product while hydrog. is used

Stage 2: Energy used to make food Stage 2 cells produce sugar Stage 2 cells produce sugar Cells use hydrogen and carbon dioxide (CO 2 ) from the air which enters on underside of leaves Cells use hydrogen and carbon dioxide (CO 2 ) from the air which enters on underside of leaves – Two gases react and produce sugars One important type is glucose…which cells use to carry out vital functions One important type is glucose…which cells use to carry out vital functions – Oxygen gas exits a leaf through the openings on its underside – Almost all the oxygen in the atmosphere comes from this process

Photosyn. Equation Raw materials on left…products on left Arrow means “yields” Energy not a raw material