MICRO-s10_05 - 2/3/2010 BIOL 240: General Microbiology...

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Unformatted text preview: 2/3/2010 BIOL 240: General Microbiology General Spring 2010 Rm. 22-116 T, Feb. 2, 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. Pre-llecture slides and study guides available on course ecture website by the night before. • (Print WISELY!! If you choose to do so..) 3. Bi-weekly lab quizzes – practice quiz & Quiz #1 DUE weekly practice TONIGHT!! – http://smccd.mrooms.net/ -- llogin with G# and Password ogin ( = birth date, MMDDYY, if new) birth 1.. Distinguish between 4 types of chemical interactions and reactions 1 Distinguish types common in living systems. List 5 special properties of water that make it properties that common the “perfect” medium for life. 2. List the 4 types of macromolecules iin living systems, and describe how n List types the components of each particular molecular structure determines its biological function. …… biological …… REVIEW: REVIEW: TODAY’s Objectives: Students should be able to….. 1. Describe 4 extracellular structures unique to Describe prokaryotes, and explain the function of each. prokaryotes 2. Compare and contrast 5 structural characteristics of the Compare gram positive and gram negative cell walls. Include gram Include illustrations. illustrations. 3. Compare and contrast 8 differences between “prokaryotic” Compare and eukaryotic cells. W hat structures do they share in What common?..... common?..... 1 2/3/2010 2. Lipids • Are the primary components of cell Are membranes. membranes. • Consist of C, H, and O. • Are nonpolar and insoluble in water. Are nonpolar and insoluble – “Hydrophobic” a.) Simple lipids • = fats or fats or triglycerides triglycerides – contain contain glycerol and fatty acids; formed by dehydration synthesis. synthesis • Unsaturated Unsaturated fats fats – have one or more double bonds in the fatty fatty acids. acids. Figure 2.9c 2 2/3/2010 b.) Complex lipids • Contain C, H, & O, + P, N, or S. • Membranes are made of phospholipids Membranes phospholipids – Hydrophilic head – Hydrophobic tail Figure 2.10 c.) Steroids • Consist of four Consist carbon rings, with an carbon with –OH group attached attached to one ring. – Are part of Are membranes. membranes – Precursors to Precursors hormones hormones Figure 2.11 3 2/3/2010 3. Proteins • Are essential in cell structure and function. 1. Enzymes are proteins that speed chemical are reactions. reactions. 2. Transporter proteins move chemicals move across membranes. across 3. Flagella are made of proteins. 4. Some bacterial toxins are proteins. Some bacterial Figure 2.12 a.) Proteins – Amino Acids a.) • Consist of subunits called amino acids. Consist amino Nonpolar Acidic, Acidic, anionic anionic Polar Table 2.4.1 4 2/3/2010 Amino Acids Acidic, Acidic, anionic anionic Basic, Basic, cationic cationic Cyclic - Nonpolar - Ionic Table 2.4.2 b.) Peptide Bonds • Peptide bonds between amino acids are between formed by dehydration synthesis/ condensation Reactions condensation Figure 2.14 5 2/3/2010 c.) Levels of Protein Structure 1. The primary structure iis a polypeptide s The primary chain chain – LINEAR SEQUENCE and number of AA’s. Figure 2.15a Levels of Protein Structure 2. The secondary structure The secondary – amino acid chain folds amino and coils in a regular helix or pleats. or – Simple folded/coiled Simple structures structures Figure 2.15b http://www.chemguide.co.uk/organicp rops/aminoacids/proteinstruct.html 6 2/3/2010 Levels of Protein Structure Figure 2.15c 3. The tertiary structure The tertiary (3D structure!!): – the helix folds irregularly, the – forming disulfide bonds, Hbonds, and ionic bonds between bonds, amino acids in the chain. amino Levels of Protein Structure 4. The quaternary structure consists of two The quaternary consists or more polypeptides. or – Two or more (≥ 2), 3D-folded polypeptides associated into a multi-peptide complex. Figure 2.15d 7 2/3/2010 d.) Complex Macromolecules • Conjugated proteins consist of amino consist acids and other organic molecules: acids 1. Glycoproteins 2. Nucleoproteins 3. Lipoproteins 4. Phosphoproteins 4. Nucleic Acids • Consist of nucleotides. Consist nucleotides • Nucleotides consist of a: – 1. 2. 3. (Phosphate-Sugar-Base) Pentose Phosphate group Nitrogen-containing (purine or pyrimidine) base or pyrimidine Figure 2.16 8 2/3/2010 a.) DNA • Has deoxyribose Has deoxyribose • Exists as a double Exists helix helix • A hydrogen bonds hydrogen with T • C hydrogen bonds hydrogen with G Figure 2.16 b.) RNA • • • Has ribose Has ribose Is single-stranded A hydrogen bonds hydrogen with U • C hydrogen bonds hydrogen with G Figure 2.17 9 2/3/2010 c.) ATP • Has ribose, adenine, and Has 3 phosphate groups phosphate X -X X X X X Figure 2.18 ATP • Is made by dehydration synthesis. Is dehydration – Absorbs/requires energy = Endergonic Absorbs/requires Endergonic • Is broken by hydrolysis to liberate useful Is hydrolysis to energy for the cell. energy – Releases energy = Exergonic Releases Exergonic 10 2/3/2010 Chapter 4 Functional Anatomy of Functional Prokaryotic & Eukaryotic Cells Cells 4.1) Prokaryotic Cells 4.1) Prokaryotic • Average size: 0.2 -1.0 µm 2 - 8 µm Average 1.0 • Basic shapes: 11 2/3/2010 • Unusual shapes – Star-shaped Stella shaped Stella – Square Haloarcula Square Haloarcula • Most bacteria are Most monomorphic monomorphic (one shape) • A few are few pleiomorphic pleiomorphic (many forms/shapes) Figure 4.5 Arrangements • Pairs: diplococci, diplococci diplobacilli diplobacilli • Clusters: staphylococci • Chains: streptococci, streptococci, streptobacilli streptobacilli 12 2/3/2010 A. Glycocalyx A. Glycocalyx Figure 4.6 • • • • Outside cell wall Usually sticky A capsule is neatly organized capsule A slime layer is unorganized & loose slime – Extracellular polysaccharide (EPS) allows cell to attach Extracellular allows – Capsules prevent phagocytosis Capsules phagocytosis • Outside cell wall • Made of chains of flagellin Made flagellin • Attached to a protein hook Attached hook • Anchored to the wall and membrane by the basal body Anchored basal B. Flagella Figure 4.8 13 2/3/2010 Flagella Arrangement Figure 4.7 Motile Cells • Rotate flagella to run or tumble Rotate run or tumble • Move toward or away from stimuli (taxis) • Flagella proteins are H antigens are antigens – e.g., E. coli O157:H7 e.g., E. CW CCW CW CCW Figure 4.9 14 2/3/2010 B2. Flagella: Axial Filaments Flagella: Axial • • • • Endoflagella In spirochetes In spirochetes Anchored at one end of a cell Rotation causes cell to move http://www.cytoviva.com/g allery_flash.htm - Borrelia Figure 4.10 C. Fimbriae & Pili C. Fimbriae Pili 1. Fimbriae allow allow attachment attachment 2. Pili are used to are transfer DNA from one cell to another one Figure 4.11 15 2/3/2010 D. Cell Wall • Prevents osmotic lysis Prevents lysis • Made of peptidoglycan (in bacteria) Made peptidoglycan Figure 4.6 Peptidoglycan • Polymer of disaccharide – N-acetylglucosamine (NAG) & – N-acetylmuramic acid (NAM) • Linked by polypeptides Figure 4.13a 16 ...
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