IRSC MCB2010 EXAM 1 ACTUAL QUESTIONS 100

IRSC MCB2010 EXAM 1 (ACTUAL / ) QUESTIONS & 100

VERIFIED ANSWERS

glycocalyces in bacterial cell - ---Answers---gelatinous, sticky substance surrounding the outside of the cell composed of polysaccharides, polypeptides, or both

2 types: capsule & slime layer

capsule (glycocalyes) - ---Answers---composed of organized repeating units of organic chemicals, firmly attached to cell surface, may prevent bacteria from being recognized by host

slime layer (glycocalyes) - ---Answers---loosely attached to cell surface, water soluble, sticky layer allows prokaryotes to attach to surfaces

flagella in bacterial cell - ---Answers---responsible for movement, long structures that extend beyond cell surface, and not present in all bacteria composed of basal body, filament, and hook

function: rotation propels bacterium through environment,

rotation is reversible, bacteria moves in response to stimuli (runs & tumbles)

fimbriae in bacterial cell - ---Answers---attach to other surfaces, sticky, bristle like projections, important function for biofilms 1 / 3

pili in bacterial cells - ---Answers---special type of fimbriae, also known as conjuction pili, 1-2 per bacterial cell, transfer DNA from one cell to another

bacterial cell walls - ---Answers---provide structure and shape and protect cell from osmotic forces, assist some cells in attaching to other cells or in resisting antimicrobial drugs,

composed of peptidoglycan, two types: gram + and gram -

gram + bacterial cell wall - ---Answers---thick peptidoglycan wall, contain chemicals called teichoic acids and lipoteichoic acids, stains purple

gram - bacterial cell wall - ---Answers---thin layer of peptidoglycan, bilayer membrane outside the peptidoglycan contains phospholipids, proteins, and lipopolysaccharide, may impede treatment of disease, stains pink

bacterial cytoplasmic membrane - ---Answers---referred to as phospholipid bilayer, composed of integral proteins and

peripheral proteins, function: energy storage, harvest light

energy in photosynthetic bacteria, selectively permeable, naturally impermeable to most substances, proteins allow substances to cross membrane and maintain concentration and electrical gradient

passive processes that move substances across membranes:

• ---Answers---diffusion, facilitated diffusion, and osmosis 2 / 3

active processes that move substances across membranes - - --Answers---active transport and group translocation

cytoplasm of bacterial cell - ---Answers---cytosol, inclusions, endospores, ribosomes, and cytoskeleton

cytosol - ---Answers---liquid portion of cytoplasm, mostly water, contains cells DNA in region called nucleoid

inclusions - ---Answers---may include reserve deposits of chemicals

endospores - ---Answers---unique structures produced by some bacteria, defensive strategy against unfavorable conditions, vegetative cells transform into endospores when multiple nutrients are limited, resistant to extreme conditions such as heat, radiation , and chemicals

ribosomes - ---Answers---sites of protein synthesis, composed of polypeptides and ribosomal RNA

cytoskeleton - ---Answers---composed of 3-4 types of protein fibers, can play different roles in cell

external structures in archaea - ---Answers---glycocalyces, flagella, fimbriae and hami

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