Bio Ch. 8

Two stages of photosynthesis

1. Light reactions

2. Calvin Cycle

In plants, glucose is made with

Carbon dioxide + water + light = glucose + oxygen + water

Oxygen exists the leaf through the

Stomata

Photosynthesis occurs in the

Mesophyll

Light Reactions produce

ATP, NADPH, and O2

The Calvin Cycle occurs in the

Stroma (of chloroplasts)

Leaves are green. They best absorb — and reflect —-.

Red/violet. Green.

Photosystem 2 occurs — Photosystem 1.

Before

PS II occurs in the

Granum

PS I occurs in the

Stroma

The main function of PS II is

Split water into O2, H+ to make electrochemical gradient and ETC

The main function of PS I is

make NADPH

Steps of PS I

1. Light enters P700

2. Ferredoxin accepts 2 high energy electrons and transfers them to NADP+ and produces NADPH

Three ways an H+ electrochemical gradient is created in plants?

1. Splitting of water in the thykaloid lumen

2. ETC pumps H+ into lumen

3. Stroma accepts H+ to form NADPH

Where is O2 produced during the light dependent reactions of photosynthesis? (PS I and PS II)

Thykaloid lumen (by oxidizing water during PS II)

Where is NADPH produced during light dependent reactions of photosynthesis?

Stroma during PS II and PS I

Where is ATP produced in the light dependent reactions of photosynthesis?

Stroma using the H+ electrochemical gradient

Cyclic electron flow is used by photosystem(s) —. It is favored by — NADP.

1. Low.

Cyclic electron flow produces —, while acyclic electron flow produces —.

Only ATP; ATP and NADPH

Components of PS II

Light harvesting (antenna) and Reaction Center

Name the three phases of the Calvin Cycle.

1. CO2 → 3PG

2. 3PG + ATP → (1,3-BPG) + NADPH → G3P

3. 10 G3P + 6 ATP → 6 RuBP

How much ATP and NADPH are used in the Calvin Cycle?

18 ATP and 12 NADPH

Purpose of RuBP in the Calvin Cycle

RuBP

Rubisco serves two functions in the Calvin Cycle.

1. To attach CO2 to RuBP

2. To attach O2 to RuBP

When is Rubisco more likely to attach to oxygen rather than carbon dioxide?

Hot and dry environments

C4 plants differ from C3 plants because they

Make 4 carbon molecule (Oxaloacetate) instead of 3-PGA in first step of Calvin Cycle

Why do some plants close the stomata during the day? This is also called the Crassulean Acid metabolism!

To preserve water