photosynthesis study guide

Photosynthesis

The process by which plant cells and algae convert light energy into chemical energy, primarily in the form of glucose.

Chloroplast

The organelle in plant cells that is responsible for photosynthesis.

Thylakoids

Disc-shaped structures within chloroplasts that contain chlorophyll and are the site of light-dependent reactions.

Stroma

The fluid surrounding thylakoids in chloroplasts, where light-independent reactions (Calvin Cycle) take place.

Grana (Granum)

Stacks of thylakoids in chloroplasts that increase the surface area for light absorption.

Photosynthetic pigments

Molecules, such as chlorophyll, that absorb light energy crucial for converting light energy into chemical energy.

Light-dependent reactions

The first stage of photosynthesis that requires light to produce ATP and NADPH.

Light-independent reactions (Calvin Cycle)

The stage of photosynthesis that does not require light and uses ATP and NADPH to produce glucose.

Reactants of Photosynthesis

Carbon dioxide, water, and light energy that plants obtain from the air, soil, and sun, respectively.

Products of Photosynthesis

Glucose and oxygen; glucose is used for energy and growth, while oxygen is released into the atmosphere.

Calvin Cycle

Series of reactions that fix carbon dioxide and use ATP and NADPH to produce glucose.

Electron transport chain

A series of complexes that transfer electrons from chlorophyll to produce energy-rich molecules during light-dependent reactions.

Chemiosmosis

The process by which ATP is produced in the light reactions of photosynthesis.

Endothermic

A reaction that absorbs energy; the Calvin Cycle is endothermic because it requires ATP and NADPH.

Inorganic vs Organic substances

Inorganic substances, like carbon dioxide, do not contain carbon-hydrogen bonds, whereas organic substances, like glucose, contain carbon and are associated with living organisms.

Light intensity effect on photosynthesis

Higher light intensity increases the rate of photosynthesis until a certain point, after which it levels off.

Optimal temperature range

The temperature range in which photosynthesis occurs most efficiently; extreme temperatures can reduce the rate.

CO2 concentration effect

Higher CO2 concentrations can increase photosynthesis rates until other factors become limiting.

Best light colors for plant growth

Blue and red light are best absorbed by chlorophyll, making them effective for photosynthesis.