Cellular Energy February 15, 2011

Homework Read pages , in your textbook Quiz on this material tomorrow (2/16/11) KNOW ALL BOLD TERMS

How do critters get their energy? Plants – Photosynthesis Animals – Glycolysis – Citric Acid/Krebs cycle (oxygen) OR fermentation (no oxygen) Energy molecule = ________

What happens when a chemical bond is broken? – Think ATP and our favorite membrane proteins So what do you think needs to happen in order to make a chemical bond? ENERGY IS RELEASED! NEED TO ADD ENERGY

How animals get their energy Basic idea: break down sugars (glucose) and use the energy in their bonds to make ATP Remember: what happens when you break chemical bonds?

Steps to making ATP Step 1: Glycolysis – Several steps that break down glucose Step 2a. FermentationStep 2b. Krebs Cycle/ Electron Transport Chain OR No oxygen aroundOxygen around

Photosynthesis What’s the point? Why do plants use it? MAKE MOLECULES THAT THE PLANTS CAN USE FOR ENERGY!!!!! – Sugar and starch – ATP

Photosynthesis: Two parts Part 1: Light reactions Part 2: The Calvin Cycle (also called the Dark Reactions) Overall reaction: 6H CO 2 + light  C 6 H 12 O 6 + 6O 2

Part 1. Light reactions What goes in What comes out SunlightOxygen gas WaterATP Other energy molecules H20H20 ATP O2O2 **Energy fixing: capture and make energy

Part 2. The Calvin Cycle What goes in What comes out ATP (from part 1) Glucose (sugar) Carbon dioxide ATP CO 2 Glucose **Carbon fixing: capture and fix carbon in glucose

ATP CO 2 Glucose H20H20 O2O2

Pigments What capture the light energy Chlorophyll a and Chlorophyll b – Why do leaves look green to us? (what light is being reflected/what light is being absorbed by the chlorophylls) – Magnesium, nitrogen Other pigments: carotenoids

Key things to know Purpose of photosynthesis Light Reaction and Calvin Cycle – What is the end product(s) in each? – What is the purpose of each step? Structure of the chloroplast – Thylakoid – Where are pigments found? Pigments used in photosynthesis – How pigments use light