MICRO-s10_09 - 2/17/2010 BIOL 240: General Microbiology...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: 2/17/2010 BIOL 240: General Microbiology General Spring 2010 Rm. 22-116 R, Feb. 17, 2010 http://www.smccd.edu/accounts/staplesn/biol240/ 1. Pre-Lab Writeups: Be sure to prepare before each Lab W riteups Be Monday’s labs (for BOTH Mon. & Wed.)!! Monday – (What? Why? How? are we doing in the lab??) 2. Midterm 1 study guides ARE updated!!! • Review session in LAB ROOM TODAY at 12:45 pm!!! • Midterm 1 on TUESDAY!!! Red scantron, #2/HB pencil, pen. REST!! Midterm scantron 3. Lab Quiz #2 due Tonight!!!! REVIEW: REVIEW: 1. Compare and contrast 8 differences between “prokaryotic” and 1. Compare and eukaryotic cells. W hat structures do they share in common? eukaryotic What 2. Recognize and describe the properties and functions of the various 2. us Eukaryotic Organelles. Eukaryotic 3. Illustrate and explain the evidence supporting the predominant Theory on heory the origin of energetic organelles in Eukaryotes. origin TODAY’s Objectives: Students should be able to….. 1. Describe how enzymes speed up chemical reactions, & Describe how how they affect the energy and equilibrium of a reaction. how 2. Describe 6 different factors that can regulate enzyme regulate activity. activity 3. Explain how Enzymes and ATP participate in Energetic Explain Coupling. Coupling 4. Diagram the investment and release of energy and Diagram Carbon atoms from Glycolysis. Carbon 1 2/17/2010 Microbial Metabolism 1. Metabolism iis the sum of the chemical s reactions in an organism. reactions 2. Catabolism is the breaking-down complex down molecules; energy-releasing processes. molecules; 3. Anabolism iis building up complex s molecules from simpler subunits; energymolecules using processes. Microbial Metabolism • Catabolism provides the building blocks and provides energy for anabolism. anabolism “Energetic Coupling!!” “Energetic Coupling!!” Figure 5.1 2 2/17/2010 Metabolism • A metabolic pathway iis a sequence of s metabolic enzymatically catalyzed chemical enzymatically catalyzed reactions in a cell. reactions 1. Metabolic pathways are determined by Metabolic enzymes. enzymes. 2. Enzymes are encoded by genes……. Therefore: Therefore: Genes drive metabolism!!! • The Collision Theory: chemical reactions The Collision chemical can occur when atoms, ions, and molecules collide – allowing exchange of electrons. allowing exchange • **Activation energy iis needed to disrupt s electronic configurations.** electronic • Reaction rate iis the frequency of collisions s with enough energy to bring about a reaction. • Reaction rate can be increased by enzymes Reaction enzymes or by increasing temperature or pressure. or temperature or pressure 3 2/17/2010 5.1) Enzymes Figure 5.2 Enzymes • Biological catalysts – Specific for a chemical reaction; not used up in Specific that reaction; usually protein that • Holoenzyme: Apoenzyme + cofactor Apoenzyme – Apoenzyme: protein – Cofactor: Nonprotein component • Coenzyme: Organic cofactor ***************************** • RIBOZYMES: = Catalytic RNA’s!! – RNA that cuts and splices RNA; in peptide RNA synthesis (ribosome)….. synthesis 4 2/17/2010 Enzymes & Important Coenzymes • • • • NAD+ NADP+ electron carriers FAD Coenzyme A – carries 2C units. Coenzyme Figure 5.3 • The turnover number is generally 1-10,000 10,000 molecules per second. molecules Enzymes Figure 5.4 http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_enzymes_work.html http://www.stolaf.edu/people/giannini/flashanimat/enzymes/prox-orien.swf 5 2/17/2010 Enzyme Classification 1. Oxidoreductase** Oxidation-reduction reactions 2. Transferase* 3. Hydrolase* 4. Lyase 5. Isomerase* 6. Ligase** Transfer functional groups Hydrolysis Removal of atoms without Removal hydrolysis hydrolysis Rearrangement of atoms Joining of molecules, uses ATP http://www.lew-port.com/10712041113402793/lib/10712041113402793/Animations/Enzyme_activity.html http://highered.mcgraw-hill.com/sites/0072507470/student_view0/chapter25/animation__enzyme_action_and_the_hydrolysis_of_sucrose.html 5.2) Factors Influencing 5.2) Enzyme Activity Enzyme • Enzymes can be denatured by temperature Enzymes denatured by and pH. and Figure 5.6 6 2/17/2010 A. Factors Influencing Enzyme A. Activity: Physical Conditions Physical • Temperature • pH • Substrate Substrate concentration concentration Figure 5.5 B. Factors Influencing Enzyme B. Activity: Competitive Inhibition Competitive • Competitive Inhibition Figure 5.7a,b http://bcs.whfreeman.com/thelifewire/content/chp06/0602001.html 7 2/17/2010 Competitive Inhibition • Eg: Sulfanilamide Sulfanilamide • Competes with Competes PABA PABA • = Sulfa Drug • Prevents Prevents conversion of PABA to folic acid folic • Cells don’t grow C. Factors Influencing Enzyme C. Activity: Noncompetitive Inhibition Noncompetitive • Noncompetitive Inhibition Figure 5.7a, c • Allosteric site (regulatory) – “different shape” induced 8 2/17/2010 D. Factors Influencing Enzyme Activity Figure 5.8 • Feedback inhibition – Often noncompetitive Often noncompetitive – Allosteric site involved http://highered.mcgrawhill.com/sites/0072943696/student_view0/chapter2/animation __feedback_inhibition_of_biochemical_pathways.html 5.3) Oxidation-Reduction • • • Oxidation is the removal of electrons. Reduction is the gain of electrons. Redox reaction iis an oxidation reaction paired s with a reduction reaction (always! ). with Figure 5.9 9 2/17/2010 Oxidation-Reduction • In biological systems, the electrons are often In electrons are associated with hydrogen atoms. hydrogen • Biological oxidations are often dehydrogenations. Figure 5.10 5.4) The Generation of ATP • ATP is generated by the phosphorylation of ATP ADP. ADP. 10 2/17/2010 The Generation of ATP • Substrate-Level Phosphorylation iis the s transfer of a high-energy organic PO4- to ADP. transfer to – The phosphate comes from an organic The phosphate comes molecule (substrate). molecule The Generation of ATP • Energy released from the transfer of Energy electrons (oxidation) electrons – of one compound to another (reduction) – is used to generate ATP by chemiosmosis. is chemiosmosis • Light causes chlorophyll to give up electrons. causes chlorophyll to – Energy released from the transfer of electrons Energy (oxidation) • from chlorophyll through a system of carrier from molecules is used to generate ATP. molecules 11 2/17/2010 5.5) Metabolic Pathways Carbohydrate Catabolism • The breakdown of carbohydrates The to release energy to 1) Glycolysis 2) Krebs cycle 3) Electron transport chain 12 2/17/2010 A. Glycolysis • The oxidation of glucose to pyruvic acid, The pyruvic acid, produces ATP and NADH. produces Figure 5.11 Energy-Consuming Stage Preparatory Stage • 2 ATPs are used ATPs • Glucose is split to Glucose form 2 Glyceraldehyde-3phosphates (G3P) 5 1 Glucose CCCCCC Glucose 6-phosphate 2 6C-P Fructose 6-phosphate 3 6C-P Fructose Fructose 1,6-bisphosphate 1,6 4 P-6C-P 2x 3C-P 3C Glyceraldehyde 3-phosphate (G3P) Figure 5.12.1 Dihydroxyacetone phosphate (DHAP) 13 2/17/2010 Energy-Releasing Stage 6 1,3-bisphosphoglyceric acid P-CCC-P 7 • 2 Glyceraldehyde-3phosphates oxidized phosphates to 2 Pyruvic acid Pyruvic • 4 ATP produced • 2 NADH produced 3-phosphoglyceric acid 8 CCC-P 2-phosphoglyceric acid 9 CCC P Phosphoenolpyruvic acid (PEP) 10 Pyruvic acid Figure 5.12.2 3C Glycolysis • Glucose + 2 ATP + 2 ADP + 2 PO4– + 2 NAD+ ADP 2 pyruvic acid + 4 ATP + 2 NADH + 2H+ pyruvic http://instruct1.cit.cornell.edu/courses/biomi290/ASM/glycolysis.dcr http://www.science.smith.edu/departments/Biology/Bio231/glycolysis.html http://highered.mcgraw-hill.com/sites/0072507470/student_view0/chapter25/animation__how_glycolysis_works.html 14 ...
View Full Document

This note was uploaded on 03/18/2010 for the course BIOL 240 taught by Professor Staples during the Spring '09 term at Canada College.

Ask a homework question - tutors are online