Bio Chapter 8 Photosynthesis (Part 2)

Why is NADPH necessary?

The high-energy electrons produced by chlorophyll are highly reactive and require a special "carrier". Therefore plants use electron carriers (NADPH) to transport high-energy electrons from chlorophyll to other molecules.

What is NADP+?

NADP+ (nicotinamide adenine dinucleotide phosphate) is a carrier molecule.

How is NADP+ converted into NADPH?

NADP+ accepts and holds high-energy electrons, along with a hydrogen ion (H+). In this way, it is converted into NADPH.

After NADP+ is converted into NADPH, where do the high-energy electrons go?

After NADP is converted into NADPH, the NADPH can carry the high-energy electrons to light-independent reactions in the stroma of the chloroplast.

What 2 parts is photosynthesis divided into?

Light-dependent reactions (AKA light reactions/LDR) and light-independent reactions (AKA the Calvin cycle/LIR).

What is the location of light-dependent reactions?

Light-dependent reactions take place in the thylakoid membrane and ONLY in sunlight (hence they depend on light).

Describe the process of how light-dependent reactions work.

Light is first absorbed by the chlorophyll molecules, and then that energy generates molecules of ATP and NADPH.

What are the reactants of light-dependent reactions?

H2O (source of electrons/H+ ions), NADP+, and ADP.

What are the products of light-dependent reactions?

O2, NADPH, and ATP.

What is the location of light-independent reactions?

Light-independent reactions take place in the stroma.

True or false: Light-independent reactions are NOT regenerative.

False: Light-independent reactions ARE regenerative.

Instead of light, what do light-independent reactions need in order to take place?

Instead of light, light-independent reactions need the products of light reactions in order to take place.

What are the reactants of light-independent reactions?

CO2 (from the atmosphere), ATP, and NADPH+.

What are the products of light-independent reactions?

Glucose (C6 H12 O6), ADP, and NADP+.

What leaves as a byproduct of light-independent reactions (when ATP converts CO2 into carbohydrates/sugars such as glucose)?

O2 leaves as a byproduct.

What do animals do with the O2 that is left as a byproduct of plants' light-independent reactions?

Animals then take in O2 and energy from plants to drive cellular respiration, which is how animals make ATP.

What factors affect photosynthesis?

Temperature, light intensity, and water availability.