Melody Daroogar OH: Monday 11 – 11:50am [email protected] At Roma Café 1 Handout 7 (Week 8 lectures) I. Gluconeogenesis: (section 14-4) A. Gluconeogenesis is the formation of glucose from non-carbohydrate sources e.g. lactate, pyruvate, amino acids, fatty acids etc. B. 3 bypass reactions of glycolysis (see figure14-16) (bypasses at the KINASE reactions) 1. Pyruvate ↔ PEP a. b. c. d. e. Biotin: cofactor of carboxylation reactions. Vitamin derived. Recognize structure (figure 14-18) 2. Fructose 1,6 bisphosphate ↔ Fru 6P a. 3. Glucose 6 phosphate ↔ Glu a. C. Regulation of Gluconeogenesis (see 15-18 and 15-22, 23) 1. 2. 3. Effects of hormones on this enzyme: a. b.Melody Daroogar OH: Monday 11 – 11:50am [email protected] At Roma Café 2 II. Pentose Phosphate shunt (section 14-5): A. Products: B. Memorize structure of NADPH C. G6P Æ Æ decarboxylation Æ ribose 5 phosphate D. Used to make nitrogenous bases, ATP, NAD(P), and other molecules important in the cell III. Chloroplasts: (see figure 19-38) A. Structure: 1. 2. 3. 4. 5. 6. B. Pigments: 1. chlorophyll: Mg center, different kinds: a, b, bacteriochlorophyll 2. phycoerythrobilin, B-carotene, lutein: conjugated double bonds 3. absorb light at different wavelengths to cover the light spectrum (be familiar with the electromagnetic spectrum) 4. chlorophyll absorbs light at blue and red wavelengths C. Fates of photons absorbed by molecules: 1. Internal conversion: 2. Fluorescence: 3. Exciton Transfer: 4. Photo-oxidation:Melody Daroogar OH: Monday 11 – 11:50am [email protected] At Roma Café 3D. Light Harvesting Complex: 1. photon absorbed and energy jumps (as exciton transfer) from one pigment molecule to another until reaches Reaction Center (photo-oxidation). 2. electron carriers in photosynthesis: a. Pheophytin: b. Plastoquinones: c. Plastocyanin: one d. Cytochromes: e. Phylloquinone: f. Fe-S centers: g. Ferredoxin: IV. Photosystems II and I (figure 19-49) A. electron transfer 1. is one at a time 2. 2 NADPH/ O2 evolved 3. 2 electrons per NADPH 4. therefore: 3 electrons/ O2 5. Mn: has 5 different oxidation states: 0, +1, +2, +3, +4 6. Mn serves as electron reservoir B. Cytochrome b6f complex (figure 19-54) 1. dimer, similar to complex III of ETC: because transfers e- from a reduced quinine to soluble carrier 2. pumps 4 H+ to lumen of thylakoid C. PSII: P680 - creates proton gradient across thylakoid membrane D. PSI: P700 – creates reduction equivalents (NADPH) E. Protons pumped to thylakoid lumen re-enter stroma through Cytoplasmic ATP-synthase F. Stacked vs. Unstacked grana (figures 19-52, 19-53) 1. Photosystems are separated from each other to prevent under-excitation of PSII 2. 3.Melody Daroogar OH: Monday 11 – 11:50am [email protected] At Roma Café 4G. Cyclic Electron Flow or Cyclic Photophosphorylation(see page 741): 1. 2. 3. 4. 5. Questions: 1. In the light dependent reactions 8 electrons are sent through both photosystems. How is this possible is the electron carriers can only accept one electron at a time? 2. What is photophosphorylation? Explain how it differs from oxidative phosphorylation. 3. How does the Z-scheme differ in the absence of water? Indicate this on the diagram below and explain the flow of the electrons. What are the products of this system? 4. The following diagram shows the Z-scheme for the light dependent reactions of photosynthesis. a. Fill in the blanks with the correct information. b. The electron carriers in the diagram are abbreviated. Write the full name of the carrier and their properties (is it a chlorophyll, quinine, etc.) c. How many protons are required to make one molecule of O2? How many electrons? How many water molecules?Melody Daroogar OH: Monday 11 – 11:50am [email protected] At Roma Café
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