Chater 8 and 9 Energy in Living Organisms CELL METABOLISM Metabolism The chemical processes occurring within a living cell Necessary for maintaining life Uses _____________________materials the cell needs enzymes Breaks down or builds

Enzymes Are ____________ Required for every chemical reaction in an organism Without, would not be able to maintain ___________ Don’t make the reaction happen that couldn’t happen on its own Make the reaction occur much _____ proteins homeostasis faster

Function of Enzymes Serve as _________ Work by lowering the _______________  energy required to get the reaction started catalysts activation energy

Characteristics of Enzymes Work best in a narrow ______________________ They are not changed or used up in the reaction; can be _______________ again They are_______________; because of their_____ _________- surface to which the enzyme binds __________- where substrate binds and undergoes a chemical reaction pH & temperature range used over & over substrate-specific shape Substrate Active site

BREAKING DOWN MOLECULES

BUILDING MOLECULES

CELL ENERGY  Energy is the ____________________ ____________: Organisms that obtain energy from consuming food ____________: Organisms that use sunlight or chemicals to convert inorganic compounds into food for energy. Example: Plants – use the process of_____________, to make their own food. This process occurs in the ____________ The equation for photosynthesis:  ability to do work Heterotrophs Autotrophs photosynthesis chloroplasts CO2 + H2O + energy → C6 H12 O6 + O2

ATP Chemical Energy Stored in ______________ Potential energy When bonds are broken; converted to _____________ in the form of ____ Food molecules cannot be used directly The amount of energy released would be ________and __________ chemical bonds useable energy ATP ATP wasteful destructive

ATP ATP- Adenosine Triphosphate ____________composed of: Nitrogen base - ________ 5-carbon sugar- ________ __phosphate groups Nucleotide adenine ribose 3 ATP

Energy is stored in ________________________bonds. ATP works like a _____________________. Cells are able to use and recycle ATP by ____________ ________________a phosphate group phosphate – phosphate rechargeable battery breaking off or adding Energy is _________ when the phosphate bond is broken ATP is converted to _____________ ____________ ADP is like an “____________” battery Energy is _______ when phosphate bond is added to ADP making ATP ATP is “__________” like a fully charged rechargeable battery released ADP- adenosine diphosphate uncharged stored recharged

Like a Rechargeable Battery

ATP – ADP CYCLE Phosphate bonds

Cellular Respiration Aerobic energy production Breakdown of glucose in presence of oxygen Produces ATP Occurs in mitochondria of eukaryotic cells Equation for cellular respiration C6 H12 O6 + O2 → CO2 + H2O + energy (ATP)

CELLULAR RESPIRATION 2 2 2 34

3 STEPS TO CELLULAR RESPIRATION Glycolysis Occurs in cytoplasm Uses 1 glucose molecule and O2 Produces 2 Pyruvic acids, 2 ATP’s and high energy e- Krebs Cycle Occurs in outer membrane of mitochondria Produces CO2 as waste, 2 ATP’s and high energy e- Electron Transport Chain Occurs in the inner membrane of mitochondria Uses O2 and high energy electrons from first 2 steps Produces H2O and 32 ATP’s

GLYCOLYSIS

KREBS CYCLE

ELECTRON TRANSPORT CHAIN

2 32 STAGE WHERE # ATP KREBS CYCLE 1 GLUCOSE GLYCOYSIS CYTOPLASM OUTER MITOCHONDRIA ELECTRON TRANSPORT CHAIN INNER 32

TOTAL ATP GAIN IN CELLULAR RESPIRATION 36 ATP per MOLECULE OF GLUCOSE

Anaerobic Energy Production Fermentation Anaerobic Energy Production Occurs if oxygen is not available Glycolysis still takes place 2 ATP’s are made for 1 glucose 2 types: Lactic acid fermentation Alcoholic fermentation

Lactic Acid Fermentation: Produces Lactic acid Human Muscle Cells Occurs when muscles run out of oxygen Muscle switches to fermentation Lactic acid builds up; causes pain, soreness & fatigue Will switch back to Cellular Respiration when oxygen is re-supplied Lactic acid is sent to liver to be broken down Bacteria some bacteria during anaerobic conditions Utilized by dairy industry to produce yogurt & cheese

Alcoholic Fermentation: Produces alcohol and CO2 Occurs in Yeast during anaerobic conditions Important in brewing & baking industries

TOTAL ATP GAIN IN FERMENTATION 2 ATP per MOLECULE OF GLUCOSE

PHOTOSYNTHESIS Process in which energy of sunlight is used to convert water and carbon dioxide into high-energy carbohydrates (sugar and starches) and oxygen, a waste product Factors affecting photosynthesis Temperature photosynthesis depends on enzymes that function best between 0o and 35o C Availability of water Shortage of water can slow or even stop photosynthesis Amount of Light Increasing light intensity increases the rate of photosynthesis

Light and Pigments   In addition to water and carbon dioxide, photosynthesis requires light and chlorophyll, a molecule found in chloroplasts. Pigment: light absorbing molecule Principal pigment is chlorophyll 2 main types chlorophyll a chlorophyll b Energy absorbed by chlorophyll is transferred directly to electrons in the chlorophyll Makes photosynthesis possible These high-energy electrons are used to help build carbohydrates.

COMPARING PHOTOSYNTHESIS AND CELLULAR RESPIRATION Occurs in the chloroplast Uses sunlight to convert H2O and CO2 into high energy sugars and O2 uses water and light splits water and releases O2 produces O2 and glucose Cellular Respiration Occurs mostly in mitochondria Uses O2 and glucose to produce H2O, CO2 and ATP uses oxygen and glucose produces carbon dioxide, water and energy (36 ATP)