Energy Generation in Mitochondria/Chloroplasts

Photosynthesis

process using energy in sunlight & CO2 to create the organic materials required of cells

Chloroplasts

• special organelle in plants

• similar to mitochondria

• proton pump creates ATP

• Stroma instead of matrix

• Has its own RNA, DNA, & ribosomes

• electron transport chain is in thylakoid membrane

Photosynthetic e- transfer reactions

• sunlight energizes e- in chlorophyll

• moves down e- transport chain

• e- from H2O makes O2 waste

• electrochemical gradient is made in the stroma

  • makes ATP

  • generates NADPH from NADP+

Carbon fixation reactions (light-independent)

• ATP & NADPH produced in light reaction used as energy

• reduces power to take CO2 & convert it to a carb

Chlorophyll

• green because it absorbs all but green light

• e- gains a higher energy level when wavelength is absorbed

Photosystem

• Chlorophylls are in a multiprotein complex

• antenna is many molecules of chlorophyll that capture sunlight

Reaction Center

• set of proteins in the thylakoid membrane

• special chlorophyll molecule that is an irreversible trap for excited e-

• transfers e- to a more stable environment

• replacement e- comes from splitting water

• when 4 e- removed O2 released

The light reaction makes what to synthesize the sugar

• ATP & NADPH

Electron from chlorophyll in photosystem 2 is donated to

a primary electron acceptor

Calvin Cycle goes around how many times?

3

Enzyme that catalyzes most reactions is

rubisco

• slow enzyme

• large quantity

• large compensation need

CO2 joins with ribulose 1.5 bisphosphate by…

carboxylase called rubisco

1 glyceraldehyde 3-phosphate in Calvin Cycle

• is generated & goes to make sugar

• large amount of energy goes to regenerate ribulose 1,5 bisphosphate

• 3 ATP & 2 NADH required per CO2

glyceraldehyde 3-phosphate

• converted to glucose

• can be shuttled into glycolytic pathway in the mitochondria

• eventually become pyruvate & ATP

• excess converted into starch in the stroma