Unit 3 Topics 1 and 2

Topic 1: Cellular energy Metabolism The sum of all reactions of an organism. Anabolic reactions Catabolic reactions Helps to maintain homeostasis. Requires energy

Cellular energy

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

Energy Big Picture ALL cells (plant and animal) need to make ATP to do work. Photosynthesis (only plants) Cellular respiration (plants and animals) 6CO H 2 O  C 6 H 12 O 6 + 6O 2

Photosynthesis: the “Big Picture”

Chlorophyll b and carotenoids are sometimes referred to as accessory pigments. Why does this make sense? Catalyst:

Leaf structure

Chloroplast structure

Stage 1: Light- dependent reactions Stage 2: Calvin cycle Light energy is converted to chemical energy (as NADPH and ATP). Glucose is made from CO 2 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 CO 2 Calvin cycle 5C RuBP 3C RuBisCo 1. Carbon fixation 2. Reduction 3. Regeneration of RuBP ribulose bisphosphate ribulose bisphosphate carboxylase 6 NADP 6 NADPH 6 ADP 6 ATP 3 ADP 3 ATP used to make glucose 3C G3P glyceraldehyde-3-P CCCCCCCCCCCCCCC 6C CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC PGA phosphoglycerate CCCCCCCCCCCCCCCCCCCCC C C C CCC == | H | H | H | H | H | H CCC –– 5C