Energy in the Cell

Energy Energy- the ability to do work or cause change All energy in living things is as chemical compounds Main energy source = THE SUN

Where Does Energy Come From? Energy is stored in food!!! Plants are autotrophs—they make their own food from sunlight. Animals are heterotrophs- cannot make their own food, must eat food for energy.

Chemical Energy 3 main chemical compounds for energy: ATP (adenosine tri-phosphate) ADP (adenosine di-phosphate) Glucose (C6H12O6)- sugar/carbs

ATP vs. ADP Break chemical bonds = RELEASE energy ATP becomes ADP by breaking a phosphate group (P) Break chemical bonds = RELEASE energy ADP becomes ATP by adding a phosphate group (P) Adding chemical bonds = STORE energy

Photosynthesis Photo: light Synthesis: make something The process by which plant cells use light energy to make food Where: chloroplasts Who: Chlorophyll- pigment that traps sun’s light energy

The Photosynthesis Reaction 6 CO2 + 6 H2O + light energy = C6H12O6 + 6 O2 trapped by chlorophyll Carbon Dioxide + Water + Sunlight = Glucose + Oxygen 2 stages: Light Reaction- needs light, oxygen released Dark Reaction- no light needed, makes sugar

Cellular Respiration The opposite of photosynthesis! Instead of making food, we break down food to release energy Takes place in mitochondria of all living things C6H12O6 + 6 O2 = 6 CO2 + 6 H2O + ATP

30 Seconds 10 Time’s Up! 3 Minutes 1 Minute 4 Minutes 1 2 5 2 Minutes Bellringer 11/112/09 In your next empty square on page 100: Write the equation for photosynthesis Write the equation for cellular respiration! Use your notes from Tuesday! Reminders: HW #10 due Fri! LAB FEE NOW! 30 Seconds 10 Time’s Up! 3 Minutes 1 Minute 4 Minutes 1 2 5 2 Minutes 8 9 7 6 4 3

Cellular Respiration Stages Glycolysis- anaerobic Citric Acid Cycle (Krebs Cycle)- aerobic ETC (Electron Transport Chain)- aerobic

Aerobic respiration -energy produced using oxygen Anaerobic respiration - also called Fermentation - a process producing energy without oxygen

Fermentation 1. Lactic Acid Fermentation- when there is no oxygen, ex: muscles while running 2. Alcoholic Fermentation - yeast, bacteria, this is how we make beer, cheese, bread, vinegar, wine and cider

Photosynthesis vs. Respiration Food made Food broken down Energy from sunlight stored in glucose Stored energy in glucose released CO2 taken in CO2 and H2O given off O2 given off O2 taken in Occurs in the presence of chlorophyll- plants only Occurs in all living organisms Light needed No light needed In Chloroplasts In Mitochondria

Photosynthesis vs. Respiration