ap biology ch 10

no offense to sedky but i hate this class lowkey why is this shit so goddamn hard

photosynthesis

Captures light energy from the sun and convert it to chemical energy stored in sugars and other organic molecules. Photosynthesis nourishes almost all the living world directly or indirectly.

Autotrophs

produce organic molecules from CO2 and other inorganic raw materials obtained from the environment.

Heterotrophs

live on organic compounds produced by other organisms. ( also fungi and prokaryotes)

Major sites of photosynthesis in most plants

Leaves

Mesophyll

The interior of the leaf, where most chloroplasts are found

Stomata

microscopic pores in the leaf

Parts of a chloroplast

inner, outer, and inter membrane, lamella, lumen, thylakoid, stroma, grana/granum

Chlorophyll

Green pigment in the chloroplasts

6CO2 + 12H2O + light energy  C6H12O6 + 6O2+ 6H2O

process of photosynthesis

light reactions

convert solar energy to chemical

Calvin cycle

uses energy from light reactions to make CO2 into sugar

photophosphorylation.

generating ATP using chemiosmosis

Do light reactions produce sugar?

No, that only happens in the Calvin Cycle

carbon fixation

beginning of carbon cycle, involves incorporating CO2 into organic molecules

light-independant/dark-cycle

metabolic reactions that don't intrinsically require light

light

form of electromagnetic energy or radiation

electromagnetic spectrum.

entire range of electromagnetic radiation

visible light

narrow band between 380 and 750 nm, visible to human eye

photon

particle of light

Visible light

radiation that drives photosynthesis

spectrophotometer

measures the ability of a pigment to absorb various wavelengths of light.

absorption spectrum

plots a pigment’s light absorption versus wavelength.

Chlorophyll a

which participates directly in the light reactions, absorbs best in the red and violet-blue wavelengths and absorbs least in the green.

Chlorophyll b

has a slightly different absorption spectrum and funnels the energy from these wavelengths to chlorophyll a

Carotenoids

can funnel the energy from other wavelengths to chlorophyll a and also participate in photoprotection against excessive light

photosystem

composed of a reaction-center complex surrounded by several light- harvesting complexes.

reaction-center complex

organized association of proteins holding a special pair of chlorophyll a molecules.

light-harvesting complex

pigment molecules (which may include chlorophyll a, chlorophyll b, and carotenoids) bound to proteins.

primary electron acceptor,

accepts an excited electron from the reaction center chlorophyll a.

Photosystem naming

in order of discovery, not in order of when they work

PSII(Photosystem 2)

has a reaction-center chlorophyll a known as P680, with an absorption peak at 680 nm.

PSI(Photosystem 1)

has a reaction-center chlorophyll a known as P700, with an absorption peak at 700 nm.

Linear electron flow

Drives synthesis of ATP and NADPH

light reactions part 1

look at the picture

light reactions part 2

look at the picture

ATP Synthase

used same as in a normal cell

Where do the protons for the gradient come from?

water

G3P

actual product of Calvin Cycle

carbon fixation phase,

Each CO2 molecule is attached to a five-carbon sugar, ribulose bisphosphate (RuBP)

rubisco

Rubisco is the most abundant protein in chloroplasts and probably the most abundant protein on Earth. Used to catalyze carbon fixation

reduction

3-phosphoglycerate receives another phosphate group from ATP to form 1,3-bisphosphoglycerate. These are then reduced into 6 G3P, which ends up into a net gain of carbohydrates. Other five are recycled to regenerate RuBP

regeneration

carbon skeletons of five molecules of G3P are rearranged by the last steps of the Calvin cycle to regenerate three molecules of RuBP. 3 more molecules of ATP are spent, it makes RuBP prepared to receive CO2

What is a main issue for plants?

dehydration

main site of water loss

stomata

What do plants do with stomata on dry days, and what does this lead to?

They close their stomata, and it leads to a large buildup of oxygen and less increase in CO2 taken in

photorespiration.

consumes ATP and doesnt produce sugar. Originally thought to be some kind of evolutionary baggage.

C4

fix CO2 in a four-carbon compound

Bundle-sheath cells

arranged in tightly packed sheaths around the veins of the leaf

C4 photosynthesis does what?

minimizes photorespiration and improves sugar production

CAM

crassulacean acid metabolism,

CAM plants

store the organic acids they make during the night in their vacuoles until morning, when the stomata close

Differences between CAM plants and C4 plants

In C4 plants, carbon fixation and the Calvin cycle are structurally separated. In CAM plants, carbon fixation and the Calvin cycle are temporally separated. Both use Calvin Cycle