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Bioenergetic Reactions

Bioenergetic Reactions. Photosynthesis & Respiration. Bioenergetic Reactions. Bioenergetic reactions that occur in living things and involve the storing or the releasing of energy. The source of energy for all living things is the sun.

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Bioenergetic Reactions

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  1. Bioenergetic Reactions Photosynthesis & Respiration

  2. Bioenergetic Reactions • Bioenergetic reactions that occur in living things and involve the storing or the releasing of energy. • The source of energy for all living things is the sun. • However, most living things cannot use energy in this form. • Bioenergetic reactions create and use energy in the form of ATP.

  3. What is ATP and ADP? • The principal chemical compound that cells use to store and release energy is adenosine triphosphate, ATP. • ATP consists of a 5-carbon sugar called ribose, and three phosphate groups. • Those three phosphate groups are the key to ATP’s ability to store and release energy. • ADP is a compound that is very similar to ATP, except it has two phosphate groups instead of three. • ADP is constantly in search of a third phosphate to convert it to ATP. • ADP does not contain as much energy as ATP. • ADP is like a half charged battery and ATP is like a fully charged battery.

  4. Releasing • When the chemical bond is broken between the 2nd and 3rd phosphate group in ATP, a tremendous amount of energy is released. • ATP has enough energy to power a variety of cellular activities. • active transport across cell membranes • protein synthesis • muscle contraction

  5. Using Biochemical Energy • One way that cells use the energy provided by ATP is to carry out active transport. • ATP is also used for the synthesis of proteins and nucleic acids and responses to chemical signals at the cell surface. • ATP is a useful source of energy, but cells only have a small amount of ATP. • It is not a good molecule for storing large amounts of energy over the long term. • Cells can regenerate ATP from ADP as needed by using the energy in foods like glucose.

  6. Photosynthetic Organisms

  7. Photosynthesis • 6CO2 + 6H2O → C6H12O6 + 6O2 • Photosynthesis uses the energy of sunlight to convert H2O and CO2 into high energy sugars and oxygen.

  8. The Process • Photosynthesis takes place in the chloroplast of the plant. • The reactions of photosynthesis occurs in two parts: light dependent and light-independent (Calvin Cycle) reactions.

  9. Light Dependent Reaction • Light is required for these reactions to occur. • This segment occurs within the thylakoid membrane of the chloroplast. • In Photosystem II, the energy from light is absorbed by the chlorophyll and transferred to the electron to energize it. • These high-energy electrons are passed on to the ETC. • The energy in these electrons are used to break up water molecules into energized electrons, hydrogen ions, and oxygen. • The oxygen is given to the atmosphere. • This process is called hydrolysis. • In Photosystem I, pigments use energy from light to reenergize the electrons. NADPH is formed. • ATP is also formed at the end of this reaction.

  10. Light-Independent Reaction • The light-independent reaction is also known as the Calvin cycle. • This reaction occurs in the stroma of the chloroplast, which is the region outside the thylakoid membrane, and does not require light. • The ATP and NADPH from the light dependent reaction are used to produce high-energy sugars. • This phase works steadily to remove CO2 from the atmosphere and turn out energy rich sugars. • The plant uses the sugars to meet its energy needs and to build more complex macromolecules such as cellulose.

  11. Chemical Energy and Food • There is quite a bit of energy contained in the food that we eat. • The process of releasing the energy contained in the foods that we eat begins with a process called glycolysis. • Glycolysis releases only a small amount of energy. • If oxygen is present, glycolysis leads to two other pathways that release a great deal of energy. • If oxygen is not present, however, glycolysis is followed by a different pathway.

  12. Glycolysis • For glycolysis to begin, 2 ATP’s must be borrowed and repayed at the end. • Glycolysis is the process in which one molecule of glucose is broken in half, producing two molecules of pyruvic acid, a 3-carbon compound. • The energy yield from glycolysis is small: 2 ATP’s, but the process itself is quite fast. • Glycolysis does not require oxygen, so energy can still be supplied when oxygen is not available.

  13. Fermentation (No oxygen = Anaerobic)Occurs outside the mitochondriaThere are two types of fermentation.http://www.5min.com/Video/How-Fermentation-Works-83226972 • Alcoholic Fermentation • Used by yeast and a few other microorganisms • Produces ethyl alcohol and carbon dioxide as wastes. • Pyruvic acid + NADH → alcohol + CO2 + NAD+ • This process is used by the beer & wine industries for the production of their products. • Lactic Acid Fermentation • Used by multicellular organisms and some unicellular organisms. • Lactic acid is produced in your muscles during rapid exercise when the body cannot supply enough oxygen to the tissues. • The buildup of lactic acid in your muscles will make them sore!! • Prokaryotes are used in the production of a wide variety of foods and beverages such as cheese, yogurt, buttermilk, and sour cream. • Pyruvic acid + NADH → lactic acid + NAD+

  14. Organisms that do aerobic cellular respiration

  15. Aerobic Cellular Respiration • This reaction releases energy from the chemical bonds of carbohydrates. • This is an aerobic process which means it requires oxygen. • This reaction takes place in an organelle called the mitochondria. • Equation: 6O2 + C6H12O6 6H20 + 6CO2 + 36ATP

  16. The Kreb’s Cycle • When oxygen is present at the end of glycolysis, the pyruvic acid passes to the 2nd stage of cellular respiration which is referred to as aerobic respiration. • This takes place inside the mitochondria. • Pyruvic acid enters the mitochondria and is broken down into CO2, NADH, ATP, & FADH2.

  17. Electron Transport Chain & Products of Krebs and ETC • Electron Transport Chain • The electrons from NADH and FADH2 are passed on to ETC. • The electrons convert ADP to ATP. • This mechanism creates the needed energy supply. • Products of Kreb’s & ETC • The Kreb’s Cycle and ETC generate 34 ATP’s. • Remember 2 molecules of ATP were produced by glycolysis. • Cellular respiration creates 36 ATP’s for every 1 sugar molecule that is processed.

  18. Used by plants and some bacteria. Photosynthesis captures energy. Reaction occurs in the chloroplast. Reactants are CO2 + H2O. Products are C6H12O6 + O2. Equation: 6CO2 + 6H2O → C6H12O6 + 6O2 Used by all organisms. Respiration releases energy. Reaction occurs in the mitochondria. Reactants are C6H12O6 + 6O2. Products are ATP + CO2 + H2O Equation: C6H12O6 + 6O2 → 6CO2 + 6H2O Photosynthesis & Respiration Comparison

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