Unit 3

Topics 1 and 2

Topic 1: Cellular energy

Metabolism

The sum of all reactions of an organism.

Anabolic reactionsCatabolic reactions

Helps to maintain homeostasis.Requires energy

Cellular energy

Why do cells need energy?Cells carry out three kinds of energy-requiring work:

ChemicalMechanicalTransport

Energy Big Picture

ALL cells (plant and animal) need to make ATP to do work.

Photosynthesis (only plants)Cellular respiration (plants and animals)

6CO2 + 6 H2O C6H12O6 + 6O2

Photosynthesis: the “Big Picture”

QuickTime™ and a decompressor

are needed to see this picture.

Chlorophyll b and carotenoids are sometimes referred to as accessory pigments. Why does

this make sense?

Catalyst:

Leaf structure

Chloroplast structure

€

6CO2 + 6H2O enzymes & chlorophyll ⏐ → ⏐ ⏐ ⏐ ⏐ ⏐ C6H12O6 + 6O2

Stage 1:

Light-dependent reactions

Stage 2:

Calvin cycle

Light energy is converted to chemical energy (as NADPH and ATP).

Glucose is made from CO2 and hydrogens carried by NADPH using ATP energy.

Photosynthesis is a net __________________________________ reaction because there is more energy in the bonds of ______________________ than there are in the bonds of the ______________________________.

Catalyst:Which enzyme catalyzes the production of ATP?

Why is water split during the light reactions?

Where does the hydrogen come from to make glucose?

Calvin cycle

What factors might affect the rate of photosynthetic reactions?

SUMMARY

starch,sucrose,cellulose& more

1C CO2

Calvin cycle

5CRuBP

3C

RuBisCo

1. Carbon fixation

2. Reduction

3. Regenerationof RuBP

ribulose bisphosphateribulose

bisphosphate carboxylase

6 NADP

6 NADPH 6 ADP

6 ATP

3 ADP

3 ATP

usedto make

glucose

3C

3CG3Pglyceraldehyde-3-P

C C C C C

C C C C C

C C C C C

6C

C C C C C C

C C C C C C

C C C C C C

C C C

C C C

C C C

C C C

C C C

C C C

PGAphosphoglycerate

C C C

C C C

C C C

C C C

C C C

C C CC C C

CC

C

C C C= =

|H

|H

|H

|H

|H

|H

C C C– –

5C