Presentation on theme: "Energy in a Cell Terms Chemosynthetic Organisms that obtain cellular energy by breaking down inorganic chemicals Autotroph creates their own food through."— Presentation transcript:
Energy in a Cell
Terms Chemosynthetic Organisms that obtain cellular energy by breaking down inorganic chemicals Autotroph creates their own food through photosynthesis or chemosynthesis. These organisms are producers. Heterotroph depends upon other organisms for nutrition. These organisms are consumers. Some organisms, such as the Euglena, will be photosynthetic in the presence of light and heterotrophic without light.
Energy Carriers ATP temporary energy storage molecule in all cells NADH H + and e - carrier molecule NAD + + H + + e - NADH FADH 2 H + and e - carrier molecule FAD + 2H + + e - FADH 2 Think of NADH and FADH 2 as taxi cabs!
NADH and FADH 2
All Cells Need Energy Cells need energy to do a variety of work: Making new molecules Building membranes and organelles Moving molecules in and out of the cell Movement
Where Does A Cell Get Energy? Food is broken down to a form the cell can use. Extra energy is stored in an ATP molecule, a nucleotide.
What Is ATP? ATP – adenosine triphosphate is a molecule made up of an adenine, ribose, and 3 phosphate groups. Adenine Ribose
A Simple Review What basic unit of what organic compound is pictured to the right? Adenine Ribose P
How Does ATP Work? Energy is stored in the bond between the second and third phosphate group. When the bond is broken, energy is released and ADP is formed. Adenine Ribose
ATP – Energy Currency Within a cell, formation of ATP from ADP and phosphate occurs over and over, storing energy each time. As the cell uses energy, ATP breaks down repeatedly to release energy and form ADP and phosphate.
Making Energy Cells make energy in two ways: Photosynthesis – takes place in the chloroplasts. Respiration – takes place in the mitochondria.
Photosynthesis Autotrophs make their own food by trapping light energy and converting it to chemical energy (carbohydrates).
Photosynthesis Using light from the sun, plants combine water and carbon dioxide to make sugar. General Equation: 6CO 2 + 12H 2 O C 6 H 12 O 6 + 6O 2 + 6 H 2 O Reactants Products light
Chemosynthesis Some autotrophs can convert inorganic substances to energy. Most are adapted to live in conditions where there is no oxygen. Marshes Lake sediments Digestive tracts of mammals Deep in the ocean
Cellular Respiration The process of breaking down food molecules to release energy. Aerobic respiration occurs in the mitochondria. Two types: Aerobic – requires oxygen. Anaerobic – requires an absence of oxygen.
Cellular Respiration – Chemical Equation C 6 H 12 O 6 + 6 O 2 _ CO 2 + _ H 2 O + 36-38 ATP enzymes
Cellular Respiration Cellular Respiration Steps Glycolysis Citric Acid Cycle Electron Transport Chain
1. Glycolysis Glucose is split to form pyruvate. Takes place in the cytoplasm of the cell. ATP and NADH are byproducts. Glycolysis Chemical Equation Glucose + 2 NAD + + 2 ADP + 2 Pi 2 pyruvate + 2 NADH + 2 ATP + 2 H 2 O Enzymes
Glycolysis C 6 H 12 O 6 C3H3O4C3H3O4 + NAD + NADH 2 ATP
Review What are the inputs for Glycolysis? Glucose 2 ATP C 6 H 12 O 6 (6 carbon molecule) 2 NAD + (coenzyme) 2 ADP+P What are the outputs for Glycolysis? 2 pyruvic acid (3 carbon molecules) 2 NADH 2 ATP (makes 4 but 2 are needed in the process)
Anaerobic Respiration Two types of anaerobic respiration: Fermentation Occurs when bacteria break down plants (vegetables and fruit) and release alcohol or vinegar. Lactic Acid Fermentation Occurs in muscles – a buildup of lactic acid causes soreness.
Aerobic Respiration 2. Citric Acid Cycle A.K.A. Krebs Cycle Pyruvate is used to build citric acid (a carbon compound), which is broken down to release ATP. (# Net 2 ATP) Takes place in the cristae (the folded membrane in the mitochondrion) CO 2 is released, and NADH & FADH 2 carry electrons and hydrogen ions to the electron transport chain. Each glucose molecule takes two trips around the cycle!
Inputs Pyruvate NAD+ FAD ADP + P i Outputs 4 NADH 1 FADH 2 1 ATP 3 CO 2 Each glucose molecule takes 2 turns through the cycle! Outputs 8 NADH 2 FADH 2 2 ATP 6 CO2
3. Electron Transport Chain Electron Transport Chain Electrons are reduced, and that energy forms large amounts of ATP. (#32-34 ATP) Takes place in the inner membrane of the mitochondrion The used ions are combined with oxygen to form H 2 O.
Electron Transport System 36-38 ATP NADH NAD+ FADH 2 FAD H2OH2O O2O2
Review What are the inputs for the Krebs cycle? 1 Pyruvate (3 carbon molecule) 4 NAD+ 1 FAD 1 ADP + P i What are the outputs for the Krebs cycle? (Per 1 pyruvate – 1 glucose yields 2X) 4 NADH 1 FADH 2 1 ATP 3 CO 2
Review What are the inputs for the ETS per one molecule of glucose? 10 NADH: 8 from Krebs, 2 from glycolysis 2 FADH 2 : from Krebs cycle O2O2 What are the outputs for the ETS? 32-24 ATP molecules H2OH2O
Total ATP Production 36 -38 ATP molecules C 6 H 12 O 6 + 6 O 2 6 CO 2 + 6 H 2 O + 36-38 ATP enzymes
MITOCHONDRION CO 2 H2OH2O O2O2 ATP NADH FADH 2 Heat Electron Transport System ATP NAD + FAD Pyruvate Glucose ATP
Sunlight Photo- System I Photo- system II NADP + ADP NADPH ATP Calvin CO 2 H2OH2O O2O2 ATP NAD + FAD NADH FADH 2 Electron Transport System Cycle Citric Acid Heat CHLOROPLASTMITOCHONDRION ATP Glycolysis Glucose Pyruvate Cycle
Citric Acid Sunlight Photo- System I Photo- system II NADP + ADP NADPH ATP Cycle Calvin CO 2 H2OH2O O2O2 ATP NAD + FAD NADH FADH 2 Electron Transport System Heat CHLOROPLASTMITOCHONDRION Glucose ATP Pyruvate Glycolysis
Cellular Respiration C 6 H 12 O 6 + O 2 CO 2 + H 2 O + 36-38 ATP 666
Oxidation - Reduction Oxidation is the loss of elecrons from an atom or molecule. It is also the loss (removal) of hydrogen atoms from a molecule. A loss of energy is associated with the loss of electrons or hydrogen atoms. Reduction is the gain of electrons or the gain of hydrogen atoms. This process stores energy.
Oxidation - Reduction Oxidation and reduction occur together. When a atom or molecule is oxidized, another must be reduced. Example: Na + Cl ® Na + Cl - - The Na is oxidized; the Cl is reduced.