Cellular Energy

February 15, 2011

Homework

• Read pages 111-113, 116-118 in your textbook

• Quiz on this material tomorrow (2/16/11)

• KNOW ALL BOLD TERMS

http://www.dezinerfolio.com/taxonomy/term/29

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. Fermentation Step 2b. Krebs Cycle/Electron Transport Chain

OR

No oxygen around Oxygen 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:6H20 + 6CO2 + light C6H12O6 + 6O2

Part 1. Light reactions

What goes in

What comes out

Sunlight Oxygen gas

Water ATP

Other energy molecules

H20

ATP

O2

**Energy fixing: captureand make energy

Part 2. The Calvin Cycle

What goes in

What comes out

ATP (from part 1)

Glucose (sugar)

Carbon dioxide

ATP

CO2

Glucose**Carbon fixing: captureand fix carbon in glucose

ATP

CO2

Glucose

H20

O2

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

http://www2.mcdaniel.edu/Biology/botf99/photo/l4ightrx.html

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