Bioenergetics.pptx.credittotheownerofthepresentation

bioenergetics. credit to the owner

1. EARTH AND LIFE SCIENCE HUMSS GRADE 11

2. Lesson 2: BIOENERGETICS Prepared By: Manuel Parilla

3. Learning Goals: Explain how photosynthetic organism use light energy to form energy-rich compounds. Describe how organism obtain and utilize energy. Recognize that organisms require energy to carry out function required for life.

4. Exercise: JUMBLED LETTER

5. RYNEEG ENERGY

6. SINSYSTHEPOOHTE PHOTOSYNTHESIS

7. ELLURCAR TARIPNIOSER CELLULAR RESPIRATION

8. Bioenergetics Is the study of how energy flows through living cells. All energy comes from the sun Animals indirectly get the energy from the sun by eating fruits / plants Autotrophs such as plant absorbs energy from the sun and stored some of it in the form of glucose

9. Bioenergetics: Photosynthesis Photosynthesis is derived from the word photo means light and synthesis means the building of a complex substance from a simple substances. The simpler substances are water, carbon dioxide, light and chlorophyll are required in this process. Photosynthesis occurs in plants, algae, certain other protest and prokaryotes. Photosynthesis is a complex series of reactions that can be summarized as the following equation:

10. Two Stages of Photosynthesis Light-Dependent Reaction Light-Independent Reaction

11. Light-Dependent Reactions Light-dependent reactions require sunlight. In the light-dependent reactions, energy from sunlight is absorbed by chlorophyll and converted into stored chemical energy, in the form of the electron carrier molecule NADPH (nicotinamide adenine dinucleotide phosphate) and the energy currency molecule ATP (adenosine triphosphate). The light-dependent reactions take place in the thylakoid membranes in the granum (stack of thylakoids), within the chloroplast.

12. Light-Independent Reactions In the light-independent reactions or Calvin cycle, the energized electrons from the light-dependent reactions provide the energy to form carbohydrates from carbon dioxide molecules. The light-independent reactions are sometimes called the Calvin cycle because of the cyclical nature of the process. Light-independent reactions do not use light as a reactant (and as a result can take place at day or night), but they require the products of the light-dependent reactions to function. The light-independent molecules depend on the energy carrier molecules, ATP and NADPH, to drive the construction of new carbohydrate molecules. After the energy is transferred, the energy carrier molecules return to the light-dependent reactions to obtain more energized electrons.

13. BIOENERGETICS: Cellular Respiration Cellular respiration is a set of metabolic reactions and processes that take place in the cells of organisms to convert chemical energy from oxygen molecules or nutrients into adenosine triphosphate (ATP), and then release waste products. Cellular respiration is a process of releasing energy stored in sugar in the presence of oxygen. Cellular respiration can be expressed in this equation:

14. Two Types of Cellular Respiration Aerobic Respiration Anaerobic Respiration Definition Aerobic respiration uses oxygen. Anaerobic respiration is respiration without oxygen; the process uses a respiratory electron transport chain but does not use oxygen as the electron acceptors. Cells that use it Aerobic respiration occurs in most cells. Anaerobic respiration occurs mostly in prokaryotes Amount of energy released High (36-38 ATP molecules) Lower (Between 36-2 ATP molecules) Stages Glycolysis, Krebs cycle, Electron Transport Chain Glycolysis, Krebs cycle, Electron Transport Chain

15. Aerobic Respiration Anaerobic Respiration Products Carbon dioxide, water, ATP Carbon dioxide , reduced species, ATP Site of reactions Cytoplasm and mitochondria Cytoplasm and mitochondria Reactants glucose, oxygen glucose, electron acceptor (not oxygen) combustion complete incomplete Production of Ethanol or Lactic Acid Does not produce ethanol or lactic acid Produce ethanol or lactic acid

16. Stages of Cellular Respiration

17. 1. Glycolysis. In glycolysis glucose (a six carbon-sugar) is converted to pyruvate (a three-organic-carbon molecule) where small amount of ATP are produced and NAD+ is converted into NADPH. This process occurs in the cytoplasm of the cell. Glycolysis that can take place without oxygen is a process called fermentation.

18. 2. Pyruvate Oxidation. Pyruvate from glycolysis goes into the mitochondrial matrix-the innermost compartment of mitochondria. There, it’s converted into a two-carbon molecule bound to Coenzyme A, known as acetyl CoA. Carbon dioxide is released and NADH is generated.

19. 3. Citric Acid Cycle. The acetyl CoA made in the last step combines with a four-carbon molecule and goes through a cycle of reactions, ultimately regenerating the four-carbon starting molecule. ATP, NADH and FADH2 are produced and carbon dioxide is released.

20. 4. Oxidative Phosphorylation. The NADH and FADH2 made in other steps deposit their electrons in the electron transport chain, turning back into their "empty" forms (NAD+ and FAD) As electrons move down the chain, energy is released and used to pump protons out of the matrix, forming a gradient. Protons flow back into the matrix through an enzyme called ATP synthase, making ATP. At the end of the electron transport chain, oxygen accepts electrons and takes up protons to form water.

21. End of Presentation