Photosynthesis Lecture Notes

Flashcards about Photosynthesis

Key knowledge of Photosynthesis

The inputs, outputs, and locations of the light dependent and light independent stages of photosynthesis in C3 plants.

C3 Plants

Majority of plants (optimal temperatures 20-25 C) – e.g. potato, wheat.

C4 and CAM Plants

Found in hot and arid regions (30-45 C) – e.g. corn, sugarcane. These plants have different photosynthetic processes due to different water and oxygen needs.

Photosynthesis is:

Anabolic - Endergonic

Chloroplasts

Found in high concentration in cells of the mesophyll layer of leaves.

Thylakoid membranes

Located in stacks called grana (granum = single), is the site of the light dependent stage of photosynthesis

Stroma

Enzyme-rich fluid surrounding grana. Site of light independent stage of photosynthesis

Chlorophyll

Pigment molecules in thylakoids that absorb light energy from sun.

Photosynthesis – light dependent stage

Light-dependent stage: Inputs are Light energy, H2O, ADP, Pi (inorganic phosphate), NADP. Outputs are O2, ATP, NADPH2

Photosynthesis – light independent stage

Light-independent stage: Inputs are NADPH2, ATP, CO2. Outputs are H2O, glucose, ADP, Pi, NADP

Rubisco

Catalyses the Calvin Cycle

Factors affecting the rate of photosynthesis

↓ light intensity = reduces rate of photosynthesis; ↓ CO2 concentration = reduces rate of photosynthesis; ↓ temperature = reduces rate of photosynthesis; ↑ than optimal temperature = reduces rate of photosynthesis