Cell Energy (Photosynthesis and Respiration) Notes Energy:

1. Cell Energy (Photosynthesis and Respiration)Notes Energy: • Energy for living things comes from food. Originally, the energy in food comes from the sun.

2. Autotroph- Organisms that use an energy source (such as light from the sun) to produce sugar • They can make their own food in their cells. • auto = self feeders • Ex: plants and some microorganisms (some bacteria and protists)

3. Heterotrophs- Organisms that must obtain food (sugar) from another organism. • Hetero –“other feeder” • Ex: animals and most microorganisms

4. Solar Energy C6H12O6 (glucose) Chemical energy Process: Photosynthesis Location: Chloroplast Enzyme: Rubisco Pigment: Chlorophyll Occurs in autotrophs O₂

5. CO2 and H2O Process: Respiration Location: Mitochondria Occurs in: Autotrophs and Heterotrophs Puts a phosphate on ADP to produce ATP (chemical energy) Some energy lost as HEAT These energy transformations provide energy for LIFE

6. Adenine Ribose 3 Phosphate groups (triphosphate) • Cell Energy: • Cells usable source of energy is called ATP • ATP stands for adenosine triphosphate

7. ATP is the only molecule the cell can actually use for cell energy. The energy released from breaking down glucose is used to put a phosphate on • Adenosine diphosphate- ADP (2 Phosphates). When ATP provides the energy for the cell it loses a phosphate.

8. Adenine Ribose 2 Phosphate groups • ADP stands for adenosine diphosphate

9. ATP Cycle ATP Loses a P- Provides energy for all cell work Energy from food used to add a P ADP ATP is like a rechargeable battery

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11. All energy is stored in the bonds of compounds—breaking the bond releases the energy • When the cell has energy available it can store this energy by adding a phosphate group to ADP, producing ATP

12. General formula for photosynthesis: carbon dioxide + water + light glucose + oxygen 6CO2 + 6H2O + light C6H12O6 + 6O2

13. Steps of Photosynthesis • Light reaction (depends on light) • Traps sunlight • Produces electrons and ATP required to power the dark reaction • Oxygen given off here • Dark reaction, aka Calvin Cycle (does not directly depend on light) • Uses ATP and electrons from light reaction and CO2 to make glucose

14. Reactants • Diagram H2O CO2 Light NADP+ ADP + P Light Dependent Reaction Calvin Cycle ATP NADPH Chloroplast C6H12O6 Glucose O2 Products

15. Summary: • Light Dependent Reaction—H2O is broken down and light energy is stored temporarily in inorganic energy carriers, ATP and NADPH • Calvin Cycle—energy is transferred from ATP and NADPH to the organic compound glucose

16. Cellular Respiration: (2 kinds—Aerobic and Anaerobic) • Cellular respiration is the process by which the energy of glucose is released in the cell to be used for life processes (movement, breathing, blood circulation, etc…)

17. Cells require a constant source of energy for life processes but keep only a small amount of ATP on hand. Cells can regenerate ATP as needed by using the energy stored in foods like glucose. • The energy stored in glucose by photosynthesis is released by cellular respiration and repackaged into the energy of ATP.

18. Respiration occurs in ALL cells and can take place either with or without oxygen present.

19. Aerobic Respiration:requires oxygen • Occurs in the mitochondria of the cell • Total of 36 ATP molecules produced • General formula for aerobic respiration: C6H12O6 + 6O2 6CO2 + 6H2O + 36 ATP glucose + oxygen carbon dioxide + water + energy Human cells contain a specialized structure – the mitochondrion – that generates energy.

20. Overall Reaction C6H12O6 + 6O2→ 6CO2 + 6H2O + 38 ATP • Overall this is a three stage process • Glycolysis: • Occurs in the cytoplasm • Glucose is broken down • Krebs Cycle • Breaks down pyruvate into CO2 • Occurs in mitochondrial matrix • Electron Transport Chain (ETC) • ATP is synthesized

21. Glycolysis • Glyco = glucose Lysis = break down • Occurs in the cytoplasm • This stage occurs in BOTH aerobic and anaerobic respiration • Glucose breaks down into 2 pyruvate (2 ATP are also made) • Glucose is a 6-carbon sugar • Pyruvate is a 3-carbon molecule (there are two of them)

22. Krebs Cycle (Citric Acid Cycle) • Occurs in the matrix of mitochondria • Main purpose is to generate electrons for use in ETC • 2 ATP is given off

23. Electron Transport Chain • ETC: A series of reactions occur (this is not just one step), to generate ATP and H2O

24. Diagram Electrons carried in NADH Mitochondria In Cytoplasm Electrons carried in NADH and FADH2 Krebs Cycle Electron Transport Chain Glucose Glycolysis 2 2 32

25. Summary: 3 steps: • 1stglycolysis • 2nd Krebs cycle • 3rd Electron Transport Chain (ETC)

26. Anaerobic Respiration:occurs when no oxygen is available to the cell (2 kinds: Alcoholic and Lactic Acid) • Also called fermentation • Much less ATP produced than in aerobic respiration

27. fermentation—occurs in bacteria and yeast Process used in the baking and brewing industry—yeast produces CO2gas during fermentation to make dough rise and give bread its holes glucose ethyl alcohol + carbon dioxide + 2 ATP

28. Lactic acid fermentation—occurs in muscle cells Lactic acid is produced in the muscles during rapid exercise when the body cannot supply enough oxygen to the tissues—causes burning sensation in muscles glucose lactic acid + carbon dioxide + 2 ATP