Cell Energy

Cell Energy The ultimate source of energy for all life is the sun. Autotrophs are organisms that can make their own food ex. plants, algae, cyanobacteria

Cell Energy Heterotrophs are organisms that have to consume food to get energy ex. animals, fungi

ATP (adenosine triphosphate) ATP is the form of energy used by cells 3 parts: adenine ribose sugar three phosphate groups

ATP Energy is stored in the bond between the 2nd and 3rd phosphate group. What molecule is made when the energy is released from the ATP? ADP

Photosynthesis

carbon dioxide + water + light  glucose + oxygen Photosynthesis 6CO2 + 6H2O + light  C6H12O6 + 6O2 carbon dioxide + water + light  glucose + oxygen What kind of organisms carry out photosynthesis? autotrophs

Photosynthesis Autotrophs have pigments – molecules that trap specific wavelengths of light Examples: Chlorophyll Carotene Xanthophyll

Photosynthesis Where in the cell does photosynthesis take place? Chloroplast

Light Reactions (light-dependent reactions) Where does it happen? thylakoid membrane What goes in? light & water What comes out? oxygen, ATP, electron carriers

Calvin Cycle (light-independent or dark reactions) Where does it happen? stroma What goes in? CO2, ATP, electron carrier What comes out? glucose sugar

Cell Respiration

oxygen + glucose  carbon dioxide + water + ATP Cellular Respiration 6O2 + C6H12O6  6CO2 + 6H2O + energy oxygen + glucose  carbon dioxide + water + ATP This is an aerobic process which means it requires oxygen

3 stages of aerobic respiration Step 1: Glycolysis Starts with glucose Produces ATP, electron carrier, & pyruvate Occurs in cytoplasm

3 stages of aerobic respiration Step 2: Krebs cycle (citric acid cycle) Starts with pyruvate (changed to acetyl-CoA) Produces CO2 , ATP, & electron carriers

3 stages of aerobic respiration Krebs cycle cont. Occurs in matrix of the mitochondria

3 stages of aerobic respiration Step 3: Electron Transport Chain Starts with electron carriers & oxygen

3 stages of aerobic respiration Produces water & ATP Occurs on inner membrane

3 stages of aerobic respiration

Fermentation This happens when NO oxygen is present. This is anaerobic, meaning . . . no oxygen is required

Alcoholic Fermentation Occurs in cytoplasm of bacteria & yeast Starts with pyruvate (from glycolysis) Produces ethyl alcohol & carbon dioxide Uses: makes alcohol & bread

Lactic Acid Fermentation Occurs in cytoplasm of muscle cells & bacteria Starts with pyruvate (from glycolysis) Produces lactic acid

Lactic Acid Fermentation Causes . . . burning sensation after vigorous exercise Uses: makes sauerkraut & yogurt