BIOM 250 1st Edition Lecture 3Outline of Last Lecture I. AtomsII. Chemical BondsIII. Chemical ReactionsIV. Inorganic CompoundsV. Organic CompoundsOutline of Current Lecture I. Cell Structure and Function of ProkaryotesII. Prokaryotes III. Gram Positive CellsCurrent LectureI. Cell Structure and Function of Prokaryotes II. Prokaryotes- a. Domain bacteria, domain archaeab. Sizes- .2 um to 2-8 um lengthc. Shapes- i. Cocci—spheresii. Bacilli—rodsiii. Spirals—helical/spirochetesd. Aggregationi. Chains—example streptococciii. Clumps—example staphylococci—clumps are harder to kille. Cell wall and external structuresThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.i. Glycocalyx- sugar coat of a cell that is a sticky, gelatinous polymer (polysaccharide and/or polypeptide)1. Can be a in a capsule form (tight) or slime layer (loose)2. Factor in pathogenesis (cause of disease)3. Can protect bacterium from recognition and phagocytosis by immune cellsii. Flagella- exterior filaments used for motility and identification1. Membrane and cell-wall bound basal body rotates the filament2. Various amounts and locations of flagella on different bacteriaiii. Fimbriae- thinner than flagella and there are typically several to hundredsper cell1. Play a role in adherence for biofilm formation or colonization of the host2. Example- E.coli 0157 fimbriae have adherence to the lining of the small intestineiv. Cell wall1. Function- Prevents cell rupture from osmotic pressurea. Protects internal plasma membrane from damageb. Provides rigidity for the cell2. Peptidoglycan- chain of linked disaccharides (NAG and NAM)a. Cross linked by peptides to provide rigidity in the cellb. If damaged by antibiotics cell may rupturei. Example- penicillin disrupts peptide bond formation and prevents cross linking in the cellIII. Gram Positive Cellsa. Contain multiple layers of peptidoglycan making them thinkb. Teichoic acidsi. Alcohol units (ex. Glycerol) and phosphatesii. Attached to peptidoglycan for rigidity c. Lipoteichoic acids- lipid end binds to plasma membraned. Function: i. Negative charges (phosphates) bind cations and regulates movement in and out of cellii. Provide rigidity during cell growthiii. Antigenic- capable of inducing an immune response because they have the ability to recognize something as
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