Chapter 3 - Cell Structure and Function Flashcards
4 Processes of life
Growth, reproduction, responsiveness, and metabolism
Prokaryotic cell shape
monomorphic, some pleomorphic; bacillus, coccus, branched, and spiral
Spiral shape categories
Spirillum, vibrio, spirochete
Glycocalyx
gelatinous, sticky substance surrounding outside of cell composed of polysaccharides, polypeptides or both; two types: capsule and slime layer
Capsule
type of glycocalyx composed of organizing NAM and NAG units, firmly attached; help prevent being recognized by host
Slime layer
type of glycocalyx loosely attached to cell surface, water soluble and allows prokaryotes to attach to surfaces
Flagella
responsible for movement, not present in all bacteria; composed of a filament, hook, rod and basal body
Arrangements of flagella
Peritrichous, monotrichous, polar, lophotrichous, amphitrichous
Motion of peritrichous bacterium
tumbles change direction, runs are direct movement in a direction
Fimbriae
sticky, bristlelike projections; adhere bacteria to one another, shorter than flagella, important in biofilms
Pili
type of fimbria, mediate the transfer of DNA from one cell to another
Bacterial cell walls
provide structure and shape, protect cell from osmotic forces, composed of peptidoglycan; two types, Gram-negative and Gram-positive
Peptidoglycan
polymer of disaccharide N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM) linked by polypeptides by the NAMs
Gram-positive bacterial cell walls
thick layer of peptidoglycan, contain teichoic acids and appear purple when stained with Gram stain
Gram-negative bacterial cell walls
thin layer of peptidoglycan, bilayer membrane with phospholipids, proteins, and lipopolysaccharide outside the peptidoglycan, appear pink when Gram stained
Atypical cell walls
acid-fast, mostly gram-positive, mycolic acid bound to peptidoglycan; mycobacterium and nocardia
Bacterial cytoplasmic membrane
phospholipid bilayer, fluid mosaic model
Bacterial cytoplasmic membrane function
energy storage, selectively permeable, maintain concentration and electrical gradient
Passive transport
simple diffusion and facilitated diffusion, require no energy
Ribosomes
prokaryotic ribosomes are 70S, eukaryotic ribosomes are 80S
Centrioles
play role in mitosis, cytokinesis, and formation of flagella and cilia; in eukaryotes
Centrosome
region of eukaryotic cytoplasm where centrioles are found
