Bellringer 11/17 1. What is energy? 2. What do the following have in common? Reminders: HW Sec 9.1 vocabulary, pay lab fee

Photosynthesis and Respiration Energy in the Cell Photosynthesis and Respiration

Energy Energy- the ability to do work The energy for living things is stored in chemical compounds 2 organelles are responsible for making those compounds for cells: Chloroplasts- through photosynthesis in plants Mitochondria- through cellular respiration in animals

Where Does the Energy Come From? Energy is stored in food!!! Plants use sunlight to make their food. Plants are autotrophs (producers)—they make their own food. Animals and other organisms that cannot use the sun’s energy directly must consume food for energy. Animals are called heterotrophs (consumers)—they cannot make their own food.

Chemical Energy Energy in food is stored in chemical bonds Food must be digested (broken down) before this energy can be used There are 3 main energy molecules that cells use: ATP (adenosine triphosphate) ADP (adenosine diphosphate) Glucose (C6H12O6)- carbohydrates

ATP and ADP ATP is made of: ADP is made of: Adenine (a nitrogen compound) 5-carbon sugar 3 phosphate groups ADP is made of: 2 phosphate groups So what’s the only difference between the two? The phosphate groups! 2 vs. 3

The ATP – ADP Cycle

ATP vs. ADP ATP can become ADP by breaking a chemical bond and removing a phosphate group When you break chemical bonds you RELEASE energy The cell can store energy by ADDING a phosphate group to ADP to become ATP. ATP acts like a fully charged battery

ATP vs. Glucose ATP is NOT good for storing large amounts of energy long-term. The cell uses glucose because it can store 90 times as much energy as ATP.

Photosynthesis Photo: using light Synthesis: to put something together >>>The process in which cell use light energy to make carbohydrates (food) Reminder: takes place in chloroplasts Chlorophyll- pigment that traps light energy needed for photosynthesis (found in chloroplasts)

Basic Photosynthesis Plants absorb carbon dioxide from the air, pull water up through their roots and use light to make sugar. Plants use the sugar to grow. Plants give off oxygen as a by-product. The green parts of the plant makes the sugar and oxygen. Carbon dioxide + water + sunlight = sugar + oxygen 

Photosynthesis Summarized __ CO2 + __ H2O + light energy = __C6H12O6 + __O2 trapped by chlorophyll But, we need to balance this equation… So…. 6 CO2 + 6 H2O + light energy = C6H12O6 + 6 O2 This process contains light-dependent (requires sunlight) and light-independent reactions (no light needed) Can we guess which part is which?

Cellular Respiration The opposite of photosynthesis Instead of making food, we now break down that food to release energy Reminder: takes place in the mitochondria C6H12O6 + 6 O2 = 6 CO2 + 6 H2O + ATP (from plants) (for plants) (for our use)

Cellular Respiration Stages Glycolysis- takes place in the cytoplasm of the cell Citric Acid Cycle (Krebs Cycle)- in the mitochondria ETC (Electron Transport Chain)- in the inner membrane of the mitochondria To remember: Glycolysis: anaerobic (no oxygen needed) Citric Acid Cycle and ETC: aerobic (need oxygen to go) Total energy after Cellular Respiration: 38 ATP

Cellular Respiration

What happens w/o O? 2 kinds of Fermentation: When the cell needs energy (when you exercise heavily or run long-distance), but little or no O is available for proper respiration, the cell will enter an anaerobic process call fermentation 2 kinds of Fermentation: Lactic Acid- this is why muscles hurt Alcoholic - used by yeast, bacteria, this is how we make beer, cheese, bread, vinegar, wine and cider

Photosynthesis vs. Respiration 

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

The ATP – ADP Cycle

Basic Photosynthesis Plants absorb carbon dioxide from the air, pull water up through their roots and use light to make sugar. Plants use the sugar to grow. Plants give off oxygen as a by-product. The green parts of the plant makes the sugar and oxygen. Carbon dioxide + water + sunlight = sugar + oxygen