1. Bioenergetics

2. The Big Picture
- energy flows through
- matter recycles

3. Producers = Autotrophs
- organisms which can make their food
- plants, algae, some bacteria
- most use photosynthesis
Consumers = Heterotrophs
- organisms which get their food from other organisms
- animals, fungi, most protists
- most use cellular respiration
ATP = Adenosine triphosphate
- normal molecule that cells use to store and release energy
- used to power all cellular work

4. 6CO2 + 6H2O ---light--> C6H12O6 + 6O2
- stores small amounts of usable energy
- cells must recycle it quickly
Photosynthesis
- process by which plants use the energy of sunlight to convert water and carbon dioxide into high-energy carbohydrates (sugars + carbs) and oxygen (a waste product)
6CO2 + 6H2O ---light--> C6H12O6 + 6O2
carbon dioxide + water ---light--> sugars + oxygen
- chlorophyll is the primary light-gathering pigment of plants
- chlorophyll reflects green light

5. See diagram page 209 in text

6. Photosynthesis happens in mesophyll cells of a leaf.
- contain chloroplasts which have thylakoids where reactions occur
- two sets of reactions:
1. Light-dependent reactions
2. Light-independent reactions = Calvin cycle
Light-dependent reactions
- require light
- happen in photosystems on thylakoid membranes
- sunlight splits water into H+ and O2
- also forms ATP and NADPH
-NADPH carries electrons (energy) to Calvin cycle

8. - excited electrons from photosystems give energy to pump H+ into thylakoid spaces and then form ATP

9. See diagram on page 211 of textbook.

10. - a concentration gradient of H+ in thylakoids is balanced by diffusion through ATP synthase
Light-Independent Reactions = Calvin Cycle
- occur in the stroma of the chloroplast
- use the ATP and NADPH from the light reactions to convert CO2 into C6H12O6
- six CO2 are needed to make one sugar molecule

11. Cellular Respiration – Ch. 9
- the energy captured in photosynthesis is released by organisms by several chemical pathways
- breaks down glucose and other food molecules in the presence of oxygen
6O2 + C6H12O CO2 +6H2O + Energy
Oxygen + glucose carbon dioxide + water + energy
- energy of food is measured in calories
- food Calorie = 1 kilocalorie (1,000 calories)
- energy of food must be released slowly and captured in the bonds of ATP

12. See page 222 in textbook

13. Glycolysis
- breaks a molecle of glucose into two pyruvic acids
- occurs in the cytoplasm of all cells with or without oxygen
- net gain of 2 ATP – not much, but very fast
- also produces 2 NADH’s which carry electrons and H+ to other reactions in the cell
Fermentation
- when oxygen is not available fermentation occurs
- yeasts and a few other organisms form alcohol
- in our muscles fermentation forms lactic acid

14. Kreb’s Cycle = Citric Acid Cycle (pg. 227)

15. Krebs Cycle = Citric Acid Cycle
- in the presence of oxygen, pyruvic acids are modified and taken into the mitochondria
- capture energy from bonds of pyruvates to form ATP, NADH, and FADH2
- occurs in mitochondrial matrix
- releases CO2
Electron Transport Chain (pg. 228)
- NADH and FADH2 from glycolysis and Krebs Cycle carry electrons (energy) to electron transport chains on inner membrane of mitochondria
- movement of electrons through E.T.C. pumps H+ into outer compartment of mitochondria to establish a concentration difference

16. - H+ can only diffuse out through ATP synthase and the energy of their diffusion is used to form ATPs
See page 228

17. Summary of ATP production in Cellular Respiration