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22 Cards in this Set
- Front
- Back
- 3rd side (hint)
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Advantages to small cells |
• Faster evolution • More surface area relative to cell volume • Support greater nutrient and waste product exchange per unit cell volume • Tend to grow faster than larger cells |
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Differences between Archaeal and Bacteria and Eukarya cell membranes |
•Archaea: Ether linkages in phospholipids; tend to be less fluid -can form lipid monolayers -have isoprenes instead of fatty acids •Others: Ester linkages in phospholipids
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Structure of Peptidoglycan |
•Sugar polymers (glycan) encircling the cell - Alternating modified glucose (N-acetylglucosamine & N-acetylmuramic acid) •Connected by crosslinking peptides (peptido) - Amino acids L-alanine, D-alanine, D-glutamic acid, & either L-lysine or DAP •Rigid layer that provides strength •Can be destroyed by lysozyme (breaks glycosidic bonds btwn sugars) •Penicillin targets cross-bridges (growing bacteria) |
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Gram Positive Bacteria |
•Cell wall is thicker, primarily 1 layer of peptidoglycan •Commonly has teichoic acids covalently bonded to peptidoglycan - Binds divalent metals prior to transport -Lipoteichoic acids: t acids covalently bonded to membrane lipids •Stain blue/purple |
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Gram Negative Bacteria |
•Cell wall has at least 2 layers: lipopolysaccharide layer (LPS) and peptidoglycan •Much less peptidoglycan; mostly outer membrane and LPS -Barrier against antibiotics and other harmful substances •Periplasm: space located btwn cytoplasmic and outer membranes -Contains many extracellular proteins •Porins: transmembrane protein channels for entrance and exit of solutes |
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Archaeal Cell Wall |
•No peptidoglycan •Instead, psuedomurein -Found in certain methanogenic archaea -Polysaccharide similar to peptidoglycan ~Contains N-acetylglucosamine (in peptido...) and N-acetylalosaminuromic acid -Beta-1,3 glycosidic bonds instead of Beta-1,4 •Cannot be destroyed by lysozyme or penicillin |
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Capsules vs slime layers |
Both are polysaccharide Capsules: tightly attached matrix Slime layer: loosely attached, easily deformed |
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Functions of Cell Surface Structures |
•Assist in attachment to surfaces •Role in development & maintenance of biofilms •Prevent dehydration/desiccation •Prevent against phagocytosis |
Capsule and Slime Layer |
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Fimbriae and Pili |
Both are filamentous protein structures Fimbriae: can be used in motility; enable organisms to stick to surfaces Pili: typically longer and fewer; conjugative/sex pili facilitate genetic exchange |
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Flagella |
•Driven by PMF •Increased/decreased rotational speed relative to strength of PMF •Helical in shape, consists of several components, reversible rotating machine, filament composed of flagellin •Several genes required for synthesis •Filament grows from tip |
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Flagella |
•Driven by PMF •Increased/decreased rotational speed relative to strength of PMF •Helical in shape, consists of several components, reversible rotating machine, filament composed of flagellin •Several genes required for synthesis •Filament grows from tip |
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Archaella |
•Driven by ATP •Half the diameter of bacterial flagella •Moves by rotation; speeds vary from 0.1-10x •Structurally similar to type IV pili •Composed of several diff. filament proteins w/ little homology to bacterial flagellin |
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Taxis and "Run and Tumble" |
Directed movement in response to chemical or physical gradients "Run and tumble " behavior: - Run: smooth forward motion, flagellar motor runs CCW - Tumble: stops and jiggles, flagellar motor rotates CW and flagellar motor comes apart |
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Endosymbiosis Hypothesis |
•Mitochondria and chloroplasts descended from respiratory and phototrophic bacterial cells •Free-living symbionts became part of eukaryotic cell |
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Evidence for Endosymbiosis |
•Both organelles contain bacterial chromosomes •Double membrane is similar to Gram (-) cell wall •Both organelles divide by binary fission •Chloroplast photochemistry is very similar to cyanobacteria •They have bacterial-like ribosomes |
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Simple Transport |
•Either symport or antiport •Driven by PMF |
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Group Translocation |
Substance transported is chemically modified, driven by phosphoenolpyruvate |
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ABC System |
Periplasmic binding proteins are involved and energy comes from ATP |
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Metabolism, Catabolism, and Anabolism |
•Metabolism: sum of all chemical rxns that occur in a cell •Catabolism: energy-releasing metabolic rxns •Anabolism: building more complex molecules from simple ones; requires energy |
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Energy Classes of Microorganisms |
•Chemoorganotrophs- oxidize organic compounds •Chemoltihotrophs- oxidize inorganic compounds •Phototrophs- convert light energy to ATP •Heterotrophs- obtain carbon from organics •Autotrophs- obtain carbon from CO2 |
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Three specific functions of cytoplasmic membrane |
•Permeability barrier- polar and charged molecules must be transported - Transport proteins accumulate solutes against the concentration gradient •Protein anchor- holds transport proteins in place •Energy conservation and consumption- Generation of the PMF |
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Three specific functions of cytoplasmic membrane |
•Permeability barrier- polar and charged molecules must be transported - Transport proteins accumulate solutes against the concentration gradient •Protein anchor- holds transport proteins in place •Energy conservation and consumption- Generation of the PMF |
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