lec 14 slide 15

what do plant cells have again

chloroplasts AND mitochondria

What is photosyntehsis in the chloroplasts linked with

oxidative phosphorylation in the miotchondria

Why do plant cells have both chloroplasts and mitochondria?

Chloroplasts perform photosynthesis (make sugars/ATP in stroma) while mitochondria perform oxidative phosphorylation (make ATP for cellular reactions outside chloroplasts).

How are photosynthesis and oxidative phosphorylation linked?

The byproducts of one process are the reactants of the other:

• Photosynthesis: CO₂ → O₂

• Oxidative phosphorylation: O₂ → CO₂

why do plant cells need mitochondria

the ATP prudced in the chloroplasts are not transported out of the stroma

Why can’t the ATP made in chloroplasts be used for all cellular reactions?

ATP in the chloroplast stroma is only used for the Calvin cycle and cannot be transported out

How do plant cells produce ATP for reactions outside the chloroplast?

Mitochondria produce ATP via oxidative phosphorylation and export it to the cytosol using the ADENINE NUCLEOTIDE TRANSPORTER (ANT)

What happens to sugars made in the chloroplast?

Sugars can be:

• Stored as starch or fat in the stroma

  • Exported to the cytosol as glyceraldehyde-3-phosphate (G3P) to make pyruvate in the cytosol

What happens to G3P in the cytosol

Converted to pyruvate through glycolysis.

What happens to pyruvate after glycolysis in plant cells?

pyruvate is transported into the mitochondrial matrix, then decarboxylated into acetyl CoA, producing 1 NADH.

What does acetyl CoA do in mitochondria?

Enters the TCA cycle → generates:

• 3 NADH

• 1 FADH₂

• 2 CO₂

then what happens to the NADH and the FADH2

donate electrons to the respiratory chain to pump protons into the crista space

after donating electrons to the respiratory chain to pump protons into the crista space what does ATP synthase do

uses that proton gradient to make ATP which is used to power all the cellular reactions outside the chloroplast

How are chloroplasts and mitochondria arranged in leaf cells?

They cluster together to optimize the coupling between photosynthesis and oxidative phosphorylation.

What is the key concept of chloroplast-mitochondria coupling?

Photosynthesis provides sugars for mitochondria → mitochondria produce ATP for the rest of the cell.