Cellular Resp. + Photosynthesis

Cellular Respiration

Using o2 to break down an organic fuel (ex. sugar)

Fermentation

partial breakdown of sugars w/o o2

Glycolysis

Breakdown of glucose, creating 2 pyruvates, 2 ATP and 2 NADH through phosphorylation. Located in cytosol.

Link Rxn

Pyruvate enters the mitochondrial matrix w/ transport proteins, carboxyl group is released, and the remaining acetyl group is attached to CoA. Produces 2 acetyl CoA, 2CO2, and 2NADH

Krebs Cycle

Acetly CoA joins w/ ocaloacatate to form citrate. Through a series of redox rxns, cycle “turns” twice for each glucose. Located in the mitochondrial matrix, occurs thru phosphorylation. Produces 2ATP, 6NADH, 2FADH2, and 4CO2

ETC

NADH and FADH2 put electrons into ETC, as e move they pump H+ ions creating a proton gradient. Ions spin the ATP synthase to catalyze ADP into ATP. Oxygen acts as final e acceptor, forming water. Occurs in the cristae. Produces ~28 ATP, 6H2O, and 10 NAD+ and 2FAD which are regenerated/oxidized.

C3 Photosynthesis

Normal photosynthesis

Light Dependent Reaction

Takes place in the thykaloid membrane, the flow of e through e acceptors pump H+ through the ATP synthase to make ATP, 9ATP and 6NADH for the Calvin cycle.

Photosynthesis 2

Occurs first in the light Dependent rxn, photolysis: H2O→ 2H+ +1/2 H2O (splits water to release oxygen, providing electrons.

Photoexcitation

Chlorophyll absorbs E, excites e into photosystem.

Photosynthesis 1

Occurs during the light Dependent Reaction, uses light to boost e to make NADPH

The Calvin Cycle

Occurs in the stroma where enzymes are, makes a 3-C sugar called triosephosphate (TP), 3ADP, and 2NADP+

Carbon Fixation

1st step of calvin cycle, CO2 combines w/ rubisco making 3 6-C sugars

Reduction

2nd step of Calvin cycle, 6 ATP and 6NADPH convert 6-C sugars into 6 3-C GP’s (Oxygen reduces to make GP)

Regeneration

3rd step of Calvin cycle, some GP make glucose, some are regenerated for RuBP accpetor

C4 Photosynthesis

Two parts of photosynthesis are separated: Light dep rxn occurs in mesophyll cell, which uses PEP (doesn’t stick to O2). Calvin cycle occurs in bundle sheath cell, isolating CO2 from O2

CAM Photosynthesis

CO2 is stored in mesophyll cell when stomata is open at night. When stomata is closed during day, light dep rxn uses stored CO2.