CH: 7 The Working Cell: Energy from Food
Compare: Both get energy from organic compounds Contrast: Autotrophs make their own organic compounds Heterotrophs get organic compounds by consuming autotrophs More Info: Autotrophs convert inorganic molecules into organic molecules On land= mostly plants In water= algae Autotroph=Producer Heterotroph=Consumer Compare and contrast how autotrophs and heterotrophs obtain food.
Cellular Respiration: Chemical Process Changes organic compound into ATP Requires oxygen ATP is used by cells for: energy Which cells? ALL CELLS perform cellular respiration Explain how cellular respiration harvests the energy in food.
Key Terms • autotroph • photosynthesis • producer • heterotroph • consumer • cellular respiration
Concept Check 7.1 • 1. Define autotroph and heterotroph, and give an example of each.2. Explain the role of food (glucose) in both photosynthesis and cellular respiration.3. Explain how life on Earth depends on the sun.
Distinguish between kinetic and potential energy. • Kinetic Energy: • Energy of anything that is in motion • Thermal Energy= energy from Moving particles (heat) • Potential Energy: • Stored energy due to position
Chemical energy= energy stored in the bonds of organic compounds Energy is released by: Cellular respiration Is a chemical reaction Requires oxygen Cells get 40% of energy from compound, 60% is lost as heat. More Info: Remember… Lipids lots of energy Carbs = Sugars= shorterm, small amounts of energy Starches= long term energy Explain what chemical energy is and how cells release it from food.
Calories amount of energy required to raise the temperature of 1 gram (g) of water by 1 degree Celsius (°C). Kilocalorie = 1000 calories More Info: “Calories” in conversation is usually a kilocalorie Define calories and kilocalories as units of energy.
7.2 Key Terms • kinetic energy • potential energy • thermal energy • chemical energy • calorie
Concept Check 7.2 • 1. Identify the types of energy you have at the top of a staircase and as you go down the stairs.2. Explain how your body uses chemical energy during exercise.3. If a food has 10 kcal of energy, how much could it increase the temperature of 100 g of water?
ATP = adenosine triphosphate The tail end of 3 P holds the energy When 1 P is removed, energy is released = ADP ATP is recycled by adding a P back to tail How ATP Packs Energy:
3 Major types of work Chemical Mechanical Transport ATP and Cellular Work
Cycle works super fast Like a rechargeable battery ATP Cycle
7.3 Key Term • ATP
Concept Check 7.3 • 1. In what way is ATP like a compressed spring?2. List three main types of cellular work.3. What is the source of energy for regenerating ATP from ADP?
Cellular Respiration • Aerobic process that releases chemical energy (from organic compounds) • Aerobic= requires oxygen • Respiration & “Breathing” • Breathing supplies cells with O2 and removes CO2 • Respiration uses the O2 and gives off CO2
Falling Electrons • As electrons fall from electron cloud (energy levels) towards nucleus- potential energy is release • Oxygen is a strong electron acceptor (pulls electrons towards its nucleus) • Hydrogen and Carbon and weak, lose electrons to Oxygen’s pull
Electron Transport Chain • Electron Transport Chain= series of atoms that transfer electrons • Each transfer releases a small amount of energy • Releases energy from large molecule in small, slow steps
7.4 Key Term • Aerobic • Electron Transport Chain
Concept Check 7.4 • Compare and contrast breathing and cellular respiration. • List the reactants and products in cellular respiration. • What is meant by the "falling" of electrons to oxygen? How does this process release energy? • How does an electron transport chain result in the gradual release of energy stored in glucose?
Structure of the Mitochondria • Mitochondria • Double membrane organelle • Inner membrane has many folds • Large surface area provides sites for C.R. • Middle contains matrix
Cellular Metabolism • Metabolism= all cellular processes combined together • C.R. , diffusion, photosynthesis, etc. • Cellular Respiration consists of a series of chemical reactions (3 Stages) • Glycolysis • Krebs Cycle • Electron Transport
Step 1: Glycolysis • Occurs outside mitochondria • Splits sugar (glucose) • Adds 2 ATPs to glucose • Energy to start the process • Results in: • 4 ATP • 2 Pyruvic Acid
Occurs inside mitochondria Pyruvic acid is converted to Acetyl CoA 1 cycle will produce 1 Acetyle CoA Cycles twice Produces 2 ATPs and 4 CO2 Step 2: Kreb’s Cycle
Step 3: Electron Transport Chain • Final Stage • 2 Parts • Electron Transport Chain • ATP Synthase- produces the ATP
ATP Synthase • Protein Structure • Converts up to 34 ATPs from each glucose molecule
Summary: • Cellular Respiration makes ATP • Glycolysis= 4 ATP – 2ATP = gain of 2 ATP • Krebs = 2 ATP • ATP synthase = 34 ATP • Total of 38 ATP per glucose molecule
7. 5 Key Terms • metabolism • glycolysis • Krebs cycle • ATP synthase
7.5 Concept Check • How is the mitochondrion's structure suited to its function? • Identify the three stages of cellular respiration, where in the cell each takes place, and how many ATP molecules it produces. • Summarize the use and production of ATP in one cycle of cellular respiration.
When does it occur? • When O2 is unavailable or supply is insufficient • ATP demand is higher that supply produced by Cellular Respiration
Fermentation in Muscle Cells • Produces ATP through glycolysis • Yields 2 ATPs • Lactic Acid is a waste product
Fermentation by Microorganisms • Occurs in anaerobic conditions • Produces ATP • Alcohol is waste product (instead of lactic acid) • Utilized by humans to make: • Bread • Wine/alcoholic drinks • Yogurt • Cheese • Soy sauce • sauerkraut
7.6 Key terms • fermentation • anaerobic
Concept Check 7.6 • 1. How is fermentation different from cellular respiration? 2. Describe one example of how fermentation in microorganisms produces human foods.3. What is the waste product of fermentation in your muscle cells?