Ch.3 Cell Structure and Function Part 1 Flashcards
How do we define a living organism?
1.) growth-increase in size
2.) Reproduce-increase in number
3.) Responsiveness- respond to their environment
4.)Metabolism- controlled chemical reactions
Does an organism have to exhibit all 4 characteristics at the same time?
No
Where do all four characteristics occur in microbes
Bacteria, archaea, and Eukaryotes
what are the characteristics of prokaryotes
-nucleoid (not a true nucleus)
-no true organelles
-simple structures
-exceptions exist
-can read genetic code and make proteins at the SAME time
includes: Bacteria and Archaea
What are the characteristics of Eukaryotes
-nucleus with nuclear envelop
-membrane-bound organelles
-larger than prokaryotes
include: Eukarya
Eukaryotes size
10-100um
prokaryotes size
smaller than 1um
what is a glycocalyx
external structure, gelatinous, sticky substance surrounding bacterial cell
what is glycocalyx composed of
Polysaccharides and/or polypeptides
what is the function
protection from desiccation (drying out)
what are the 2 types of glycocalyx
1.) capusle (help prevent bacteria from being recognized by the host-pathogenicity)
2.) slime layer (helps attach to surfice and is loosely atatched)
describe the flagella
-provide motility within environment
-structure is a filament (hollow and composed of flagellin)
how many types of bacterial flagella?
2
flagella continued describe the structure
-powered by protons
-rotates 360 degrees
run-counterclockwise
tumble-clockwise
what is chemotaxis
movement toward or away from a stimulus
living cells must respond to what
the environment
what does atrichous mean
no flagella
what does peritrichous mean
all over
what does monotrichous mean
polar (one flagella at one end)
what does lophotrichous mean
tuft at one end
what is a spirochete
corkscrew and moves forward
what is an axial filament
rotates around the cell
what is a fimbriae
-shorter than flagella
-attaches to surfaces
-biofilms
-movement
what is pili
-longer than fimbriae but shorter than flagella
-used to transfer DNA during conjugation
what is a biofilm
slime matter
-organized, layered system of bacteria and other microbes attached to a surface
why live in a biofilm?
-communicate via chemical and electrical signals
-formation of different structures
-protection from toxic compounds and antibodies
what is the cell wall charactersitics of domain bacteria
-provide structure
-provide shape
-protect from osmotic forces
-attachment to other cells
-resist antibiotics
-composed of peptidoglycan
what is cocci
spheres
what is bacilli
rods
what is spirillum
spirals
what are the arrangements for domain bacteria external, structures
Di/Diplo-pairs
Strepto-chains
staphylo-clusters
what is the Domain bacteria cell wall composed of
peptidoglycan
peptido
NAG-NAM chains connected by a tetra peptide
glycan
complex polysaccharide composed of alternating sugars NAG and NAM
what does the tetra peptide chain link to
NAG and NAM
Define gram-positive
Thick layer of peptidoglycan
Embedded with teichoic acid
-negatively charged molecule
-help anchor peptidoglycan to membrane
Can contain mycotic acid
-helps prevent desiccation
-must use acid fast stain
ex: TB and leprosy
Define gram-negative
2nd phospholipid bilayer
-protect against antibiotics
-porins
-lipopolysaccharide (LPS)
-Lipid A: endotoxins
-when released can cause shock, inflammation, blood clots
Periplasmic space
-contains enzymes, nutrients, etc
-think layer of peptidoglycan
-is pink/red after gram-staining
in the cytoplasmic membrane describe the head and tail of a phospholipid bilayer
Head: hydrophilic (Outside)
Tail: Hydrophobic (inside)
what is the function of the cytoplasmic membrane
produces energy
-energy storage
-harvest energy (phtosythesis)
-Selectively permeable
what are the 2 types of movement in the cytoplasmic membrane
Passive and active
what is passive movement
-diffusion
-facilitated diffusion
-osmosis
what is active movement
-active transport
-group translocation
