Cell Energy Cell Energy The ultimate source of

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: 1. adenine 2. ribose sugar 3. three phosphate groups

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

Photosynthesis

Photosynthesis 6 CO 2 + 6 H 2 O + light C 6 H 12 O 6 + 6 O 2 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? CO 2, ATP, electron carrier �What comes out? glucose sugar

Cell Respiration

Cellular Respiration 6 O 2 + C 6 H 12 O 6 6 CO 2 + 6 H 2 O + 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-Co. A) �Produces CO 2 , 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