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Cellular Energy

Cellular Energy. Energy is essential for life Plants can use the suns energy to make food Other living things get food by eating plants All energy starts with the sun to plants. Cells need energy Active transport Cell division Mitosis Making proteins Movement through flagellum or cilia.

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Cellular Energy

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  1. Cellular Energy

  2. Energy is essential for life • Plants can use the suns energy to make food • Other living things get food by eating plants • All energy starts with the sun to plants

  3. Cells need energy • Active transport • Cell division • Mitosis • Making proteins • Movement through flagellum or cilia

  4. What do you do when you need energy? • You eat • What do cells do when they need energy? • Use ATP

  5. Adenosine triphosphate- is a molecule that is used by cells for fast energy • The molecules store energy as molecular bonds • ATP can store up to 3 phosphate groups

  6. ATP is not easy to make • Because there are charged particles so close together it takes a lot of energy just to make ATP

  7. There is a cycle between used molecules and making molecules • ATP is used by cells for energy. The molecule is now known as adenosine diphosphate because it has 2 phosphate groups. The cell can then add a third phosphate group back on to keep a constant flow of energy. • The cell also does not have to store ATP molecules and waste energy, it can just make more

  8. ATP has the most energy stored in it • ADP has less because a bond was broken • Some cell functions can use ADP for energy because they do not need the high energy bonds of ATP • AMP has even less. • The more bonds the molecule makes, the more energy it has

  9. How cells use ATP molecules • The molecules will bind to a specific site on a protein • The bonds are broken and energy is released to the protein to carry out what it is to do • The ADP molecule then leaves the site to recharge • A new ATP molecule then lands on the binding site and the cycles continues

  10. Photosynthesis • Photosynthesis- the process of using the suns energy to make simple sugars that can then be stored as starches • This happens in 2 phases • Light dependent reactions • Light in-dependent reactions

  11. photosynthesis • Photosynthesis happens inside the chloroplast in the thylakoid membrane • This membrane contain pigments which will absorb specific wavelengths of light

  12. photosynthesis • The most abundant pigment is chlorophyll which absorbs all wavelengths but green. That is why plants are green.

  13. photosynthesis • Light dependent reactions • This step occurs in 2 photosystems. • Photosystem 2 is first and uses shorter wavelengths of light at 680 or less • Photosystem 1 is next and uses longer wavelengths of light at 700 to get more energy • A photosystem is found inside the thylakoid membrane • Stomata open for air exchange- lose water and O2, let CO2 in

  14. photosynthesis • Photosystem 2 (P680) • Light energy is transferred to excited electrons inside the thylakoid membrane of chlorophyll. • Electrons are passed down an electron transport chain. These are proteins embedded in the membrane. • Electrons lose energy at each protein as they are transferred. • The resulting weak electrons can be used to make ATP or to help get hydrogen into the thylakoid membrane by splitting water

  15. Photosystem 2 makes • Splits water (photolysis) and gets • ½ oxygen released to the air • 2 hydrogen ions sent to the thylakoid • 2 electrons sent to chlorophyll to replace the used ones • Hydrogen is then used to help make ATP by diffusing through the membrane

  16. Photosynthesis • Photosystem 1 (P700) • The electrons from photosystem 2 are re-excited by a stronger wavelength of light • They are then attached to an electron carrier, NADP+ • 2 electrons and 1 hydrogen are bound to the molecule making NADPH, a stable molecule that can store energy for use in light independent reactions

  17. Photosynthesis • Light independent reactions • No light needed for this • It is called the Calvin Cycle and is used to make sugars for the plant in the stroma of the chloroplast • it uses the energy that was stored as ATP and NADPH during light reaction in the thylakoid membrane

  18. Three CO2 attach to three 5Csugars called Ribulosebiphosphate (RuBP)to make three 6C sugars • They break immediately and form six 3C sugars • NADPH and ATP are used to add high energy bonds and remove a phosphate from the 3C sugars forming phosphoglyceraldehyde (PGAL) • One of the PGAL is sent to the cytoplasm to BE made into larger sugars • ATP is used to make the five 3C PGAL into three 5C RuBP and the cycle starts again

  19. It takes 3 rounds of the cycle to make 6 molecules of PGAL

  20. Cellular Respiration • Occurs in the mitochondria of the cell • Breaks down food to make ATP • 3 stages to respiration • Glycolysis • Krebs cycle • Electron transport chain

  21. Aerobic- oxygen is needed to work correctly • Anaerobic- no oxygen is needed

  22. respiration • Step 1-glycolysis • Occurs in the cytoplasm • Breaks down glucose sugars (6 carbon) into 2 pyruvic acid molecules (3 carbon) • Makes 2 ATP molecules • Makes 2 NADH electron carriers

  23. respiration • Pyruvic acid (pyruvate) diffuses across membrane of the mitochondria • Where it combines with coenzyme A to form acetyl-CoA • Oxygen is needed for this process to form CO2

  24. respiration • Step 2- Citric Acid Cycle (Krebs Cycle) • Acetyl CoA enters the Krebs cycle and is attached to a 4 carbon molecule called oxaloacetic acid to make citric acid • This breaks down into a 5 carbon sugar and CO2. it also produces NADH+H • Breaks down again to form a 4 carbon sugar, CO2, NADH+H, and ATP • 4 carbon sugar is then rearranged back into oxaloacetic acid to keep the cycle going, creating NADH+H,FADH2

  25. Total energy made in Krebs cycle • 1 ATP is made • 3 NADH+H electron carriers are made • 1 FADH electron carrier • 2 CO2 • Each electron carrier passes 2 electrons onto the transport chain in the next step

  26. Krebs Cycle (citric acid cycle)

  27. respiration • Step 3 - electron transport chain • NADH and FADH2 give up stored electrons made during the krebs cycle • Electrons are then passed from protein to protein slowly releasing energy, some of which turns into ATP to pump H+ ions into the inner membrane of the mitochondria • This makes the inner membrane positive and the outer membrane negative

  28. With this, 4 positive hydrogen's are then pulled back across joining with the final electron acceptor, Oxygen, and 4 electrons to make 2 waters and 32 ATP • Oxygen is very important at this step, without it, the entire process stops • Respiration makes 36 ATP for every 1 molecule of glucose. It is very effective for energy production

  29. Lactic acid fermentation • Starts with glycolysis making pyruvic acid, but without oxygen the electron transport chain stops. • Therefore NADH produced during citric acid cycle dumps energy onto 2 pyruvic acid molecules made in glycolysis to make lactic acid. This frees NAD+ to then be resused • Makes 2 ATP molecules

  30. Lactic acid build up occurs in the cells and is then broken down later by the liver into pyruvic acid once respiration starts again. • This build up of lactic acid is what causes muscles to hurt after a hard anaerobic exercise

  31. Alcoholic fermentation • Used by yeast and bacteria • Breaks down glucose (6C) and makes pyruvate (3C) • 3C pyruvate then makes two CO2 molecules and 2 acetaldehyde (2C). • Acetaldehyde accepts energy from NADH made from glycolysis to form 2 ethyl alcohols (ethanol) • Makes 2 ATP

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