1. Energy in a Cell Chapter 9

2. Goals How cells get energyHow cells get energy PhotosynthesisPhotosynthesis Cellular RespirationCellular Respiration

3. ATP Adenosine TriphosphateAdenosine Triphosphate Energy = ATPEnergy = ATP Made up of:Made up of: AdenosineAdenosine Ribose – sugarRibose – sugar 3 – phosphates – positively charged particles3 – phosphates – positively charged particles

4. ATP Energy of ATP is stored in the bonds between the phosphatesEnergy of ATP is stored in the bonds between the phosphates Phosphate bonds break = energy is releasedPhosphate bonds break = energy is released ADPADP

5. ADP Adenosine DiphosphateAdenosine Diphosphate Made ofMade of AdenosineAdenosine RiboseRibose 2 phosphates2 phosphates

6. Forming & breaking down ATP Adenosine – P= little energyAdenosine – P= little energy Adenosine – P – P= more energyAdenosine – P – P= more energy Adenosine – P – P – P= Tremendous EnergyAdenosine – P – P – P= Tremendous Energy

7. Cells need energy for: Making new molecules = EnzymesMaking new molecules = Enzymes Maintain HomeostasisMaintain Homeostasis –Break down food molecules Send Nerve ImpulsesSend Nerve Impulses ReproductionReproduction Movement = Cilia & FlagellaMovement = Cilia & Flagella

8. 9.2 Photosynthesis Plants trapping sunlight energy to make sugar/glucosePlants trapping sunlight energy to make sugar/glucose Converting sunlight energy to chemical energyConverting sunlight energy to chemical energy

9. Photosynthesis 6CO 2 + 6H 2 O + Sun → C 6 H 12 O 6 + 6O 26CO 2 + 6H 2 O + Sun → C 6 H 12 O 6 + 6O 2 Takes place in ChloroplastTakes place in Chloroplast

10. Chloroplast

11. Chlorophyll – Pigment that absorbs specific wavelengths of sunlightChlorophyll – Pigment that absorbs specific wavelengths of sunlight Chlorophyll a & b absorb all wavelengths of sunlight exceptChlorophyll a & b absorb all wavelengths of sunlight except Pigments – molecules that absorb specific wavelengthsPigments – molecules that absorb specific wavelengths

12. 2 phases of Photosynthesis 1.Light – dependent rxn - Energy to make glucose 2. Light – independent rxn - Make glucose

13. Light – Dependent Rxn Converts sunlight energy into chemical energyConverts sunlight energy into chemical energy

14. Light – Dependent Rxn How does it work?How does it work? 1.Sunlight energy excites electrons in the chlorophyll 2.Excited electrons pass from chlorophyll to Electron Transport Chain (ETC)

15. Electron Transport Chain (ETC) Series of proteins in the thylakoid membraneSeries of proteins in the thylakoid membrane Each step of ETC small amounts of energy are lostEach step of ETC small amounts of energy are lost Energy lost used to make ATP from ADP & pump H + ions back to thylakoid membraneEnergy lost used to make ATP from ADP & pump H + ions back to thylakoid membrane

16. ETC Electrons move down ETC then transferred to Stroma where NADP + accepts the electronElectrons move down ETC then transferred to Stroma where NADP + accepts the electron NADP + - Nicatinamide adenine dinucleotide phosphateNADP + - Nicatinamide adenine dinucleotide phosphate

17. NADP + Electron carrier moleculeElectron carrier molecule Becomes NADPH when it accepts electrons (end of ETC)Becomes NADPH when it accepts electrons (end of ETC)

18. NADPH Provides energy to form carbohydrates or glucoseProvides energy to form carbohydrates or glucose Photolysis – Splitting of water to replace electrons = oxygen we breathePhotolysis – Splitting of water to replace electrons = oxygen we breathe

19. ETC

20. Chloroplast

21. Light Independent RXN Also known as Calvin CycleAlso known as Calvin Cycle Does not require sunlightDoes not require sunlight

22. Calvin Cycle Series of rxns that use CO 2 to build carbohydrates or glucoseSeries of rxns that use CO 2 to build carbohydrates or glucose Takes place in stroma of chloroplastsTakes place in stroma of chloroplasts

23. Calvin Cycle 1.Carbon fixation – 1 carbon atom from CO 2 is added to a 5 carbon sugar 2.6 carbon sugar from #1 splits in two molecules of PGA (phosphoglyceric acid) 3.Several rxns take place = 2 molecules PGAL form by using ATP & NADPH from light rxn

24. Calvin Cycle 4.Several cycles = 2 PGAL leave to form Glucose 5.Some PGAL reform 5 carbon sugar that we started with - Ready for a new Calvin Cycle to start - Ready for a new Calvin Cycle to start

25. 9.3 Cellular Respiration Process which mitochondria breaks down food to produce ATPProcess which mitochondria breaks down food to produce ATP C 6 H 12 O 6 + 6O 2 → 6CO 2 + 6H 2 O + EnergyC 6 H 12 O 6 + 6O 2 → 6CO 2 + 6H 2 O + Energy Takes place in MitochondriaTakes place in Mitochondria

26. 3 Stages of Cellular Respiration Anaerobic – without O 2Anaerobic – without O 2 1.Glycolysis – series of rxns that breakdown glucose (6 carbon) into 2 molecules of Pyruvic acid (3 carbon)

27. Glycolysis Takes place in cytoplasm of cellTakes place in cytoplasm of cell 2 ATP used to start2 ATP used to start 4 ATP produces4 ATP produces Net gain = 2 ATPNet gain = 2 ATP NAD + electron carrier moleculeNAD + electron carrier molecule

28. 3 Stages of Cellular Respiration Aerobic – with O 2Aerobic – with O 2 2.Citric acid cycle – (Krebs cycle) –Series of rxns breakdown carbohydrates or glucose –Opposite of Calvin cycle –2 ATP produced –3 NADH + H + produced = 1 NADH = 3 ATP –2FADH produced = 1 FADH = 2 ATP –2 CO 2 produced

29. 3 Stages of Cellular Respiration AerobicAerobic 3.ETC –Takes place in Mitochondria –NADH & FADH pass electrons along releasing small amounts of energy –Pump H + back to center of mitochondria –Final electron acceptor = O 2 –Without O 2 chain becomes blocked –32 ATP produced

30. ETC – cellular respiration

31. Fermentation Without O 2Without O 2 Allows our cells to continue to make ATP w/o O 2 after glycolysis for a short period of timeAllows our cells to continue to make ATP w/o O 2 after glycolysis for a short period of time

32. Fermentation 1.Lactic acid – 2 lactic acid molecules are byproducts of producing just 2 ATP –Occurs in muscle cells

33. Fermentation 2.Alcoholic – ethyl alcohol is formed as a byproduct to produce 2 ATP –Occurs in yeast cells and bacteria

34. Comparing ATP production Process ATP produced ATP used Net gain Glycolysis422 Citric acid cycle 202 ETC32032 Lactic acid 202 Alcoholic202