Ch. 8.1 & 9 ATP, Cellular Respiration and Photosynthesis

I. Living things need energy… Moving muscles B. Building essential molecules C. Transporting substances across cell membranes.

II. Where do we get energy? Food 1. to grow 2. to reproduce.

III. Sources of Energy A. Autotrophs (plants) B. Heterotrophs 1. can make own food 2. by process of photosynthesis 3. also called Producers B. Heterotrophs 1. get food from others 2. called consumers

Plants and animals need each other to survive.

IV. Chemical Energy Stored in chemical bonds of compounds. B. Compounds that store energy: ATP, NADH and FADH2. Building Bonds = stores energy Breaking Bonds = releases energy

So what does ATP stand for? Many Uses 1. Mechanical functions of cells 2. Carry out Active transport 3. Breakdown large molecules ATP Adenosine Triphosphate

The Three Components of ATP Adenine Ribose 3 Phosphate groups Go to Section:

How does ATP store energy? 1. Energy is stored in ATP’s high-energy phosphate bonds. Energy is released when the high energy phosphate bond between the 2nd and 3rd “P” is broken. Ribose Adenine P

How does ATP store energy? 2. When a free phosphate group is attached onto ADP, energy is stored in this bond to create ATP. Energy + ATP ADP + P + Energy

ADP P ATP Using ATP Energy Energy Released For the cell to release and use the energy in ATP, the bond between the 2nd and 3rd phosphate groups must break; leaving ADP and a free phosphate group. Energy Released Adenine Ribose P P P ADP P ATP

ATP /ADP Cycle Energy Stored Energy Energy Released Energy A working muscle recycles over 10 million ATPs per second!!! Energy Energy Stored ATP ATP ATP /ADP Cycle Bonds Formed to make ATP Energy Released ADP P P P ADP Energy Released to do work ADP ADP Bonds Broken

PHOTOSYNTHESIS

What is photosynthesis? A chemical reaction in which plants take the light energy from the sun and convert it to chemical energy to make their own food.

Plants cells contain organelles called CHLOROPLASTS Chloroplasts contain chlorophyll (green color) which makes photosynthesis possible. Carbon Dioxide enters the leaves through the stomata (openings) and combines with the stored energy in the chloroplasts to make glucose. Glucose is moved through the phloem to the rest of the plant.

Glucose is used as a food source for the plants to carry out life processes. Unused glucose is stored as a starch or becomes part of the plant’s tissue.

Chemical Equation-Photosynthesis Reactants Products 6 CO2+ 6 H2O + sunlight 6 O2 + C6H12O6 Carbon dioxide +water +sunlight (yields) oxygen + glucose How does this relate to Cellular Respiration?

Once plants change the energy from the sunlight into chemical energy during photosynthesis, organisms then have to change that chemical energy into a form that is usable by the organism’s cells during a process called Cellular Respiration.

What is cellular respiration? The release of chemical energy by breaking down glucose and other food molecules for use by the cells.

CELLULAR RESPIRATION Reactants Products C6H12O6 + 6O2 --> 6CO2 + 6H2O + 36 ATP (glucose + oxygen  carbon dioxide + water + energy) - 2 forms: Aerobic (with O2 - oxygen) Anaerobic (without O2- oxygen) Reaction is opposite of Photosynthesis

AEROBIC RESPIRATION takes place in the presence of oxygen: (3 steps) Glycolysis- occurs in the cytoplasm producing 2 ATPs and 2 pyruvates.

Krebs Cycle- takes place in the mitochondria. uses the 2 pyruvates from glycolysis and releases 2 ATPs, 6CO2 and many NADH & FADH2

Electron Transport- takes place in the mitochondria. Uses the NADH & FADH2 from Krebs and produces 32 ATPs and 6H2O

ANAEROBIC RESPIRATION (no oxygen present) Glycolysis- produces 2 ATP’s and 2 pyruvates Alcoholic Fermentation in yeast OR Lactic Acid Fermentation in muscles