AP Biology - Unit 3: Cellular Energetics

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Photosynthesis

Conversion of light energy from the sun into chemical energy (Glucose).

Cellular Respiration

The breaking down of glucose into chemical energy (ATP).

Mitochondria

Organelle in both prokaryotic and eukaryotic cells where cellular respiration occurs

Chloroplast

Organelle found only in plant cells that is responsible for turning solar energy into glucose

Glycolysis occurs where?

cytoplasm or cytosol

Citric Acid Cycle occurs where?

mitochondrial matrix

Identify the structure

Electron Transport Chain (in respiration) occurs where?

Inner mitochondrial membrane

Electron transport chain (in photosynthesis) occurs where?

Within the thylakoid membrane of the chloroplast

What are granum?

A stack of thylakoids within the chloroplast

Cristae

Infoldings of the inner membrane of a mitochondrion that houses the electon transport chain and the enzyme catalyzing the synthesis of ATP.

What is Photosystem II?

A photosystem that contains a pair of P680 chlorophyll molecules.

What does Photosystem II use absorbed light energy for?

To split water into protons and oxygen.

What does Photosystem II produce?

ATP.

What is Photosystem I?

What prokaryote evolved into the chloroplast?

Cyanobacteria

Evidence of endosymbiosis in chloroplast and mitochondria

1. Chloroplasts & Mitochondria have their own circular DNA (similar to nucleoids in prokaryotes).

2. Prokaryote-like ribosomes

3. Double membranes

4. Both reproduce through binary fission

BE SURE TO LIST SEPARATELY ON AN FRQ!!! (i.e. Chloroplasts have DNA. Mitochondria have DNA.)

What prokaryote evolved into the mitochondria?

Alpha-proteobacteria

How do plants capture light?

pigments (most commonly chlorophyll)

Where are the pigments of a chloroplast found?

In the thylakoids

Produced molecules of LDR

O2, NADPH, ATP, Hydrogen ions

What pigment is in PS II?

P680

What pigment is in PS I?

P700

Where are water molecules split in photosynthesis?

First step in PS II

What photosystem occurs first?

PS II (Named PS II due to being discovered second its kinda dumb)

When sunlight hits electrons in a photosystem, it is called ____?

Photoexcitation

The ETC in photosynthesis pumps protons _ of the thylakoid membrane.

Inside. This creates a chemiosmotic gradient that will power ATP Synthase

The ETC in respiration pumps protons ____ of the mitochondrial inner membrane.

Outside. Same chemiosmoticgradient concept as photosynthesis, but in the opposite direction.

LEO the lion goes? (Loses Electrons = Oxidation)

GER (Gains Electons = Reduction)

What does NADP+ Reductase do?

Reduces NADP+ to NADPH (Sounds like the opposite)

First phase of the Calvin Cycle?

carbon fixation phase- traps carbon dioxide molecules

Second phase of the Calvin Cycle?

Energy investment and harvest phase - matter is pulled out and becomes part of the plant

Third phase of Calvin Cycle?

regeneration of the CO2 acceptor (RuBP)

CO2 is combined with RuBP using which enzyme?

RuBisCo

Carbon fixation phase ends with?

Two 3 carbon molecules resulting from adding carbon from CO2 to a five carbon molecule

Where does the Calvin Cycle take place?

Stroma

What does NADPH do in the Calvin Cycle?

Provides energy for the creation of glucose

What does rubisco do in the Calvin cycle?

Enzyme that attaches CO2 to 5 carbon RuBP, phosphorylyzing it into 3-phosphoglycerate

3-Phosphoglycerate (3-PGA)

2 Molecules yielded by the first stage of the Calvin cycle after the short-lived 6 carbon molecule dissociates

What turns 3-PGA into 3-BPG?

Phosphorylizing by ATP, which turns into ADP

3-Biphosphoglycerate (3-BPG)

First molecules of the 2nd stage of the Calvin cycle - receive energy from NADPH, produced by the LDR (turns into NADP + Pi). These molecules come from phosphorylation of 3-PGA

Glyceraldehyde 3-Phosphate (G3P)

Molecule involved in the third stage of the Calvin Cycle, some molecules leave to become part of the plant while the remainder is phosphorylated by ATP and is used to regenerate RuBP

Correct order of molecules in the Calvin Cycle?

3-PGA, 3-BPG, G3P

What molecule leaves the Calvin Cycle to become part of the plant?

Glyceraldehyde 3-Phosphate (G3P)

C3 Plants

Use RuBisCO as first carbon fixation enzyme, produced 3-PGA as first stable product, prone to using photorespiration in hot conditions.

C4 Plants

Uses PEP Carboxylase instead of RuBisCO, first product is oxaloacetate (4 carbons), CO2 fixation happens in mesophyll cells, and the Calvin Cycle happens in the bundle sheath cells

CAM Plants

Stomata opens at night, CO2 is fixed into organic acids at night, and CO2 is released during the day for the Calvin Cycle