1.  Energy is never created or destroyed, only transformed  Entropy (disorder) increases Laws of thermodynamics

2.  Convert energy source to ATP: usable cellular energy Transforming energy lightfood ATP

3. ATP: Energy Currency for the cell  Phosphate bonds are highly unstable. H2OH2O PiPi  G = -7.3 kcal/mol

4. ATP powers many reactions in cells

6. Active transport  Specific transport protein required  Energy required!  Any kind of molecules  Either direction  Can move against gradient  Can transport all molecules  No equilibrium

7. Simple active transport  Energy from ATP

8. Simple active transport  Energy from ATP  Directional transport  One kind of molecule

9. Simple active transport  PMCA transporter removes Ca 2+ from cytoplasm  Very low [Ca 2+ ] required for signaling Ca 2+ ATP ADP

10. How do we get ATP from Glucose?  Transfer energy stored in glucose to a storage molecule  ATP  NADH  Glycolysis- Oxidizing glucose to pyruvate  Citric Acid Cycle – Oxidizing pyruvate to CO2  Election Transport – Collecting electrons from NADH and transferring this energy towards making ATP.

11.  H-C-OH units  Often used for energy by cells  Glucose is a simple 6C sugar Carbohydrates

12.  Polymer: polysaccharides (complex carbohydrates)  starch  cellulose  glycogen  chitin  peptidoglycan Carbohydrates

13.  Gain of electrons  Increased number of bonds to O  O pulls e – from C Oxidation H – C – H H – – H most reduced H – C – H OH – – H H – C – H O –– H – C – OH O –– O = C = O most oxidized

14.  When one molecule is oxidized, another is reduced  Electron carriers (“coenzymes”): NAD +, FAD Oxidation reactions H – C – H OH – – H H – C – H O –– oxidation 2 e – reduction NAD + NADH oxidation

15.  Glucose → CO 2 is highly exergonic  Same reaction as burning paper or wood  Oxidation “Burning” sugars free energy (G) reaction progress → glucose CO 2

16.  Glucose → CO 2 is highly exergonic  Same reaction as burning paper or wood  Oxidation “Burning” sugars O = C = O

17.  Glucose → CO 2 is highly exergonic  Same reaction as burning paper or wood  Oxidation “Burning” sugars free energy (G) reaction progress → glucose CO 2

18.  Glucose → CO 2 is highly exergonic  Same reaction as burning paper or wood  Oxidation “Burning” sugars free energy (G) reaction progress → glucose CO 2

19.  Biochemical pathway  Enzymes catalyze steps  Energy captured in ATP “Burning” sugars free energy (G) reaction progress → glucose CO 2

20. higher energy lower energy  Oxidized molecules have less chemical energy  Energetic electrons transferred to carriers “Burning” sugars free energy (G) reaction progress → glucose CO 2 H – C – H OH – – H H – C – H O –– oxidation 2 e – reduction NAD + NADH

21.  Complete oxidation of glucose 4 stages:  Glycolysis  Citric acid cycle  Electron transport  Chemiosmosis Aerobic cell respiration 6 CO 2 oxidation glucose

22.  Partial oxidation of glucose in cytosol 1. Glycolysis 2 pyruvate oxidation glucose 2 ATP, 2 NADH Yum! gluT

23.  First step: phosphorylation catalyzed by hexokinase  Energy invested  Allows facilitated transport 1. Glycolysis glucose 6-phosphate hexokinase glucose ADPATP P

24. hexokinase  Another phosphorylation step  6C molecule split into two 3C molecules 1. Glycolysis glucose 6-phosphate glucose ADPATP P ADPATP P P P P PFK

25. hexokinase  Oxidation  Energy stored as high-energy e – on NADH 1. Glycolysis glucose 6-phosphate glucose ADPATP P ADPATP P P P P NADHNAD + NADHNAD + P P P P PFK

26. ATP hexokinase  2 ATP synthesis steps  Net gain of 2 ATP per glucose  6C glucose → 2 3C pyruvates 1. Glycolysis glucose 6-phosphate glucose ADPATP P ADPATP P P P P NADHNAD + NADHNAD + P P P P ATPADP ATPADP ATPADP P P pyruvate PFK

27.  AKA tricarboxylic acid cycle (TCA), AKA Krebs cycle  Occurs in matrix of mitochondria (or cytosol in prokaryotes) 2. Citric Acid Cycle (CAC)

28.  “Transition step”  Transport into matrix  Connects glycolysis to CAC 2. Citric Acid Cycle (CAC) cytosol i.m. o.m. matrix acetyl CoA pyruvate CO 2 Coenzyme A NADH NAD +

29.  “Transition step”  Large protein complex spans o.m. and i.m.  Transporter and enzyme  Oxidation of one carbon to CO 2  Attachment of coenzyme A 2. Citric Acid Cycle (CAC) cytosol i.m. o.m. matrix acetyl CoA pyruvate CO 2 Coenzyme A NADH NAD +

30.  2C acetyl CoA + 4C = 6C citric acid 2. Citric Acid Cycle (CAC) acetyl CoA citric acid

31.  2 oxidation reactions complete the oxidation of glucose 2. Citric Acid Cycle (CAC) acetyl CoA CO 2 CoA NADH NAD + citric acid NADH NAD + CO 2

32.  One GTP synthesized and converted to ATP 2. Citric Acid Cycle (CAC) acetyl CoA CO 2 CoA NADH NAD + citric acid NADH NAD + CO 2 ATP GDP GTP ADP

33.  Two more oxidation steps regenerate original 4C molecule 2. Citric Acid Cycle (CAC) acetyl CoA CO 2 CoA NADH NAD + citric acid NADH NAD + CO 2 ATP GDP GTP ADP FADH 2 FAD NADH NAD +

34.  Where’s the carbon from glucose? 2. Citric Acid Cycle (CAC)

35.  Where’s the carbon from glucose? 6 CO 2  Where’s the energy from glucose? 2. Citric Acid Cycle (CAC)

36.  Where’s the carbon from glucose? 6 CO 2  Where’s the energy from glucose?  4 net ATP (2 from glycolysis, 2 for each pyruvate in CAC) 2. Citric Acid Cycle (CAC)

37.  Where’s the carbon from glucose? 6 CO 2  Where’s the energy from glucose?  4 net ATP (2 from glycolysis, 2 for each pyruvate in CAC)  10 NADH (2 glycolysis, 2 transition, 6 CAC) 2. Citric Acid Cycle (CAC)

38.  Where’s the carbon from glucose? 6 CO 2  Where’s the energy from glucose?  4 net ATP (2 from glycolysis, 2 for each pyruvate in CAC)  10 NADH (2 glycolysis, 2 transition, 6 CAC)  2 FADH 2 (CAC) 2. Citric Acid Cycle (CAC)