Exam 1 - Lecture 2 Flashcards
what name is given to sphere-shaped bacteria?
coccus/cocci
what name is given to rod-shaped bacteria?
bacillus/bacilli
describe diplococci
pairs of cocci
describe streptococci
chains of cocci
describe staphylococci
grape-like clusters of cocci
describe a tetrad
4 cocci in a square
describe sarcina
8 cocci in a cube formation
describe streptobacilli
chains of bacilli
describe coccobacilli
very short rods
describe vibrios
curved rods/crescent shaped
describe a spirillum
a short, rigid helix (looks like a curly hair)
describe spriochetes
long, flexible helix (long curly hair)
what is mycelium?
network of long, multinucleate filaments (network of hyphae)
define pleiomorphic
having many forms or shapes
order these organisms in order of genome size (smallest to largest)
- viruses
- eukaryotes
- prokaryotes
smallest
- viruses
- prokaryotes
- eukaryotes
largest
true or false: small cell size decreases surface-to-volume ratio
false, small cell size increases surface-to-volume ratio
which has a bigger surface-to-volume ratio: spheres or rods?
rods
what are two things that increase surface-to-volume ratio?
convolutions and microvilli
what are the common layers of bacterial cells?
- cytoplasm
- cell envelope
- external structures
what are the three components of the bacterial cell envelope?
- plasma membrane
- cell wall
- capsule or slime layer
which component of the cell envelope is an absolute requirement for all living things?
the plasma membrane
what are the functions of the plasma membrane?
- encompasses the cytoplasm
- selectively permeable barrier
- interaction with external environment
- metabolic processes
what is the fluid mosaic model of the plasma membrane?
lipid bilayer with proteins (half lipids, half proteins)
what characteristic is defined as having both hydrophobic and hydrophilic ends, like membrane phospholipids?
amphipathic
what percent of membrane proteins are peripheral proteins, and what percent are integral proteins?
20-30% peripheral, 70-80% integral
which membrane proteins are amphipathic?
integral proteins
which are more fluid: saturated or unsaturated lipids?
unsaturated
what are the sterol-like proteins that are present in the bacterial membrane?
hopanoids
what are common examples of growth factors needed by bacteria?
- amino acids
- purines and pyrimidines
- vitamins
- heme
what is passive diffusion?
molecules move from one region of higher concentration to one of lower concentration between the cell’s exterior and interior
- H2O, CO2, and O2 often use this method
what are four transport mechanisms microorganisms use to get most of their nutrients?
- facilitated diffusion
- active transport
- group translocation (bacteria and archaea only)
- endocytosis (eukarya only)
what mode of transportation typically involves carrier proteins and is not energy dependent?
facilitated diffusion
describe active transport
- energy-dependent process (ATP or proton-motive force)
- moves molecules against the concentration gradient
what are the three types of active transport?
- primary active transport
- secondary active transport
- group translocation
what do primary active transporters need?
what is another name for primary active transporters?
- ATP (energy)
- ATP-binding cassette (ABC) transporters (uniporter)
what do secondary active transporters use to cotransport substrates (like protons, sodium ions, etc.)?
ion gradients
what are the two types of cotransporters?
- symporter (two substances move in the same direction)
- antiporter (two substances move in opposite directions)
what is group translocation?
energy dependent transport that chemically modifies molecules as it’s brought into the cell (i.e., phosphorylation)
how do microorganisms take up iron?
they secrete siderophores that complex with the iron and brings the iron into the cell
what are the functions of the cell wall?
- maintain the shape of the bacteria
- helps protect the cell from osmotic lysis
- helps protect from toxic substances
- may contribute to pathogenicity
which stains purple, which stains pink?
- Gram-negative
- Gram-positive
- purple: Gram-positive
- pink: Gram-negative
which has a thicker peptidoglycan layer: Gram-positive or Gram-negative?
Gram-positive
which has a thinner periplasmic space: Gram-positive or Gram-negative?
Gram-positive
what is the major component of the bacterial cell wall?
peptidoglycan
what is the area between the plasma membrane and peptidoglycan called?
the periplasmic space/periplasm
describe the structure of peptidoglycan
- alternating NAM and NAG sugars
- peptide strands of alternating D- and L- amino acids
- NAM has the peptide chain coming off of it
what kind of structure do peptidoglycan monomers form?
a helical structure
what kind of linkage do the peptidoglycan chains have in E. coli?
direct linkage
what kind of linkage do the peptidoglycan chains have in S. aureus?
indirect linkage
