Chapter 3: Prokaryotic Cell Structure and Function

Question 1

Bacterial Morphology

Answer 1

Morphology: study of shape
Bacillius: rods
coccus: round (multiple-cocci)
cocobaccillius: round/elongated/stubby
vibrio: comma shaped
spirilium: thick, slick, long (worm looking)
spirochete- tiny, tightly coiled/long and skinny (corkscrew)
star-…

pleomorphic- many shaped

Question 2

Arrangements

Answer 2

-coccus shaped
DIPLOcoccus- 2 stuck together
STREPTococcus- strep/chain
TETRAD- group of four (::)
SACRINAE: 4 on top of 4
STAPHYLoccoci: stacking like grapes/a lot

-bacillius shaped
PALISADE- stuck together like llllllll
STREPTbacillus: chain ———

Question 3

External Structures- Glycocalyx (Capsules, slime layer)

Answer 3

Chemical Composition: polysaccarides and mucopolypeptides (proteins)
Function: barrier against harmful chemicals (survival)
protection against phagocytes
used for attachment to surfaces
emergency energy source
formation of biofilm

Question 4

External Structures- Pili and Fimbriae

Answer 4

Chemical Composition: protein fibrils
Function: (only in bacteria)
fimbriae (attachment)
pili (attachment and genetic exchange)
antigenic in humans and animals (foreign makes immune response)

Question 5

External Structures- Flagella

Answer 5

Chemical composition-
Function- motility
types:
monotrichous- 1 tail
amphitrichous- coming out both ends of microbe
lophotrichous- multiple tails
peritrichous- covering the entire microbe external surface
endoflagella- only seen in spirochete/internal flagella

Question 6

Cell Wall

Answer 6

Chemical Composition: peptidoylan (murein) cross-linked polymer of repeated units (sugar deprived from N-Acetylglucosamine NAG and N-Acetylmuramic acid NAM)
Function: provide the wall with high mechanical strength

chemicals that will break up the cell wall: lysozyme (enzyme) found in tears/saliva/sweat via hydrolysis

Tetra-peptide cross links: NAM cross link to other NAMs in NAM and NAG chains
Penicillin will inhibit cross link formation, wall will eventually break apart/fall apart

Question 7

Gram stain (+)

Question 8

Gram Stains (-)

Answer 8

Has an outer membrane protecting the cell wall both superficial and deep. hydrophobic/mostly lipids
Amoxilcillin: wide spread antibiotic, penicillin but fat soluble to attack gram - bacteria
penicillin can’t kill gram - bacteria

Porins: allows materials through gram - cell membranes
Lipopolysaccarides- found in gram - cell membranes, released into bloodstream that are toxic to humans-endotoxins

Question 9

Cell membranes and transports

Answer 9

(Plasma or cytoplasmic membrane)
Chemical Composition: Composed primarily of phospholipid, Chemoreceptors are found on the cell membrane
Functions: Responsible for selective permeability (often mediated by carrier proteins)

Passive diffusion: high to low concentrations, no energy required
-facilitated diffusion: pathways for larger substances
-osmosis: H2O through channels high to low
Active Transport: (forced diffusion) using ATP/energy against gradient

Question 10

Cytoplasm, Inclusions, and Ribosomes

Answer 10

Cytoplasm (cytosol) primarily of water (80%) 20% dissolved solutes, ions, substrates.
Inclusions: storage areas in cell, contains nutrients
Ribosomes: protein synthesis “small” can be inhibited by certain antibiotics

Question 11

Chromosome, Plasmid, Endospores

Answer 11

Chromosome :singular/circular
:genomic or chromosome DNA
Plasmid: extra-chromosomal genetic elements composed of DNA, may be copied and shared among bacteria
Endospores: only found in Gram (+) bacteria and bacillis and clostridium genera
Spore production: sporogenesis

Question 12

Eukaryotic

Answer 12

Has a nucleus
mitochondria for ATP synthesis (used to be a bacteria)
moves with flagella