HARVESTING ENERGY FROM FOOD Cellular Respiration

What is Cellular Respiration? Cellular Respiration is the process by which the energy stored in food (glucose) is released Energy for all life processes comes from the chemical energy stored in the bonds of organic compounds This process occurs in both plants AND animals Crash Course: Cell Respiration

Cell Respiration Equation Equation in Words: Equation Using Molecular Formulas

Complimentary Reactions Photosynthesis:  6CO2 + 6H2O + Light Energy  6O2 + C6H12O6 Cell Respiration:  C6H12O6 + 6O2  6CO2 + 6H2O + Energy (ATP) The Products of Photosynthesis are the Reactants of Cell Respiration! The Products of Cell Respiration are the Reactants of Photosynthesis!

Phase One Phase Two Also called glycolysis Occurs in the cytoplasm Glucose is split into two molecules of Pyruvic Acid Makes 2 ATPs OCCURS IN EVERY ORGANISM Occurs in the mitochondria Pyruvic Acid produced in glycolysis undergoes a series of chemical reactions to make 34 additional ATPs OCCURS ONLY WHEN OXYGEN IS AVAILABLE Two Phases of Cell Respiration

Anaerobic Organisms ONLY If NO OXYGEN is present, FERMENTATION occurs in the cytoplasm. If oxygen IS present, cell respiration will finish up in the mitochondria.

Aerobic Anaerobic Uses oxygen Completed in the mitochondria Complete break down of glucose Produces 36 ATP Very efficient but SLOW Does not use oxygen Completed in the cytoplasm Glucose is only partially broken down Produces only 2 ATP Inefficient but FAST Also called fermentation Types of Respiration

Alcohol Fermentation - ~Occurs in yeast and bacteria - ~Ethyl Alcohol and carbon dioxide are waste products - ~Used in making alcoholic beverages and in making bread dough rise! Glucose  2 Alcohol + 2 Carbon Dioxide + 2ATP

Lactic Acid Fermentation Occurs in muscle cells when oxygen is in very low supply Lactic acid is produced as a byproduct (causes your muscles to feel sore and tired) Used in bacteria that produce lactic acid in dairy products like cheese and yogurt Glucose  Lactic Acid + 2 ATP

ATP is a nucleic acid! It has a sugar, phosphate groups, and a nitrogenous base! ATP = Adenosine Triphosphate A form of energy used by all cells for all life processes (rather than glucose) An organic molecule containing high energy phosphate bonds

How Does ATP Give Us Energy? ATP contains three phosphate groups The bond between the second and the third phosphate is VERY IMPORTANT When it is broken, a lot of energy is released In this way, ATP gives us energy!

The ATP-ADP Cycle When our body needs energy, the special high energy bond between the second and third phosphate is broken. Now the molecule is called ADP (adenosine diphosphate) When our body needs to make more ATP, cellular respiration adds a phosphate back on to an ADP molecule, making ATP again

Uses of ATP

Cell Respiration Summary 1. What is cell respiration? 2. True or False: Only animals undergo cellular respiration 3. What is the formula for cell respiration? 4. What is the first phase of cell respiration called? Where does it occur and what does it make? 5. If oxygen is available, where does the second phase of cell respiration occur? What about if NO oxygen is available? 6. What are the products of the two types of fermentation? 7. How does ATP provide energy?

Answers: 1. Cellular Respiration is the process by which the energy stored in food is released 2. FALSE 3. C 6 H 12 O 6 + 6O 2  6H 2 O + 6H 2 O + 36ATP 4. Glycolysis- occurs in the cytoplasm, makes 2 pyruvic acids and 2 ATP 5. The Mitochondria, The Cytoplasm 6. Alcohol = CO2 and Alcohol. Lactic Acid = Lactic Acid 7. The high energy bond between the second and third phosphate is broken

Use the following diagram to explain how photosynthesis and cell respiration are complimentary reactions. Photosynthesis makes glucose and oxygen, which are the raw materials for cell respiration. Cell respiration makes carbon dioxide and water, which are the raw materials for photosynthesis. Plants release O2 into the atmosphere, to be used by animals during respiration. Animals release CO2 into the atmosphere, to be used by plants during photosynthesis