9.1 Section Objectives – page 221 1. How is each of these organisms using energy? 2. In what other ways do organisms use energy? 3. What are two ways in which organisms make/get energy? (organisms can either be ____ or _____) 9.1 Section Objectives – page 221

Energy in a Cell The Need for Energy All organisms require energy for: Active transport Cell division Movement Production of proteins

Energy in a Cell Plants and other green organisms are able to trap the light energy via sunlight and store it in bonds for later use Other organisms do not use the sun directly: They eat plants to obtain energy stored in plants

Energy in a Cell Energy is stored in the ATP molecule ATP: adenosine triphosphate Made up of adenosine + 3 phosphate groups

*This energy is released when the bond is broken* Energy in a Cell ATP Adenosine Phosphate High-energy bond: Stores a lot of energy *This energy is released when the bond is broken* ADP Energy Adenosine Phosphate

Energy in a Cell ADP: Adenosine diphosphate Cells recycle the ADP to make new ATP to store more energy for future use Many proteins have spots where ATP attaches to provide energy for the protein to do its job, then the ADP is released for recycling

Photosynthesis Process that uses the sun’s energy to make glucose Purpose is to trap sun’s energy and store it in glucose (food for the plant) Carried out by green plants and some bacteria Photosynthesis occurs in the chloroplast

Photosynthesis Structure of the chloroplast: Stroma: Space inside the chloroplast Thylakoid: Green disk in the chloroplast Granum stack: Stack of green thylakoids

Photosynthesis Thylakoids are green because they contain chlorophyll Chlorophyll: green pigment in plants that absorbs light energy Pigment: light-absorbing compound

Photosynthesis: The Chemical Equation 6CO2 + 6H2O + light energy  C6H12O6 + 6O2 carbon dioxide + water + sunlight  glucose + oxygen (Light Energy  Chemical Energy) http://www.pbs.org/wgbh/nova/nature/photosynthesis.html

Photosynthesis: The 2 Steps 1. Light reaction (Light-dependent reaction) - First step of photosynthesis that traps sunlight and makes electrons and ATP to run the dark reaction 2. Dark reaction (Light-independent reaction) - Second step of photosynthesis that uses ATP and electrons from the light reaction and carbon dioxide from the air to make glucose

Cellular Respiration Cellular respiration: process by which cells (animal and plant) break down food molecules into ATP (energy) http://www.sumanasinc.com/webcontent/animations/ content/cellularrespiration.html

Electron Transport Chain Animal Cell Citric Acid Cycle (Outer Membrane) Electron Transport Chain (Inner membrane) 2 Glycolysis (Cytoplasm) 1 3

Cellular Respiration THE POINT: SO YOU’RE PROBABLY THINKING…WHAT WAS THE POINT OF ALL THIS!!! THE POINT: ATP Totals for aerobic respiration: Glycolysis – 2 ATP Citric Acid Cycle – 2 ATP + Electron Transport Chain – 32 ATP 1 Glucose = 36 ATP in all for aerobic respiration

What happens when oxygen is NOT present? Glycolysis—Always Anaerobic Alcoholic fermentation Pyruvate  ethyl alcohol + carbon dioxide Lactic Acid fermentation Pyruvate  lactic acid Carried out by your muscles when you’re exercising hard (need ATP) and can’t get oxygen into you fast enough (can’t do aerobic respiration) Causes muscle cramps and soreness Carried out by yeast and some bacteria Used in brewing beer, making wine, and baking bread and cakes

Cellular Respiration Photosynthesis and respiration are the opposite of each other: Photosynthesis Plants use sunlight to make glucose take in carbon dioxide give off oxygen *carbon dioxide + water + sunlight  glucose + oxygen Respiration Animals and plants eat plants to get glucose take in oxygen give off carbon dioxide *glucose + oxygen  carbon dioxide + water + ATP