1.4 cell walls and envelopes

why is it impossible for microbes to survive and grow using just glycolysis and hexose sugars?

A. its not impossible

B. too few ATP are generated

C. the NAD+ needed will run out

D. pyruvate will build up and back up

E. C and D

E

loosely, gram + bacteria have _____ while gram - have ______

walls; envelopes

teichoic acids are often beneficial in ______ or ______. why?

probiotics; yogurts; it interacts with the immune system to reduce inflammation and protect against harmful bacteria

mycolic acid is only found in?

mycobacteria

what is the unique feature of bacteria compared to other microbes? (and is often a target for abx)

peptidoglycan

what aspect of bacteria is the only aspect that is more complex than euk?

envelope, wall, or membranes

peptidoglycan is a ______ ______ polymer

sugar; peptide

bacteria cell walls help to maintain _______ and _____ provide them with ________ and is important in resisting changes in ________

size; shape; strength; osmolarity

the lipid bilayer contains what three things

-transport machinery

-secretion apparatus

-environmental sensors

what transport machinery is anchored to the cytoplasmic membrane in bacteria?

flagella and pili

peptidoglycan is created via what repeating structures?

disaccharide and cross-linking peptides

before the cross-linkage is made, what makes up the disaccharide chain?

double D-alanine

what aspect of peptidoglycan is often a target for abx

peptide cross links

gram + have _____ ______ and do not have _______

teichoic acids; LPS

teichoic acids are + or - charged?

- (anionic)

the very outer surface of gram + or - bacteria is surrounded by?

+/- polysaccharide capsules

mycobacteria are gram -/+?

+

mycobacteria are different in their outer layers how?

they are surrounded by mycolic acid (lipids) that allow them to be acid fast

mycolic acids are thought to be compared to ______ as it is very resistant to _____ ______

wax; drying out

what does acid fast mean?

Resistant to decolorization so acid is used to decolorize

the outer half of the outer membrane of Gr - bacteria is composed of?

LPS (lipopolysaccharide)

is LPS found in Gr + bacteria?

no

what are the two parts of LPS

O-antigen and Lipid A

the O-antigen is helpful sometimes in ?

strain typing

what is Lipid A?

component that is an "endotoxin" and bioactive leading to inflammatory responses

what is the generalized structure of Lipid A

carbohydrate chain

what is the space between the outer and inner cytoplasmic membrane in gr - bacteria? what does it contain

periplasm; protein, lipoprotein

beyond the cell wall, what structure may gr-/+ have?

carbohydrate capsule

what is the use of carbohydrate capsule?

adhesion, contrib to forming biofilm, evasion of immune system, reduce phagocytosis

carbohydrate capsules allow bacteria to grow in the _____ ______

blood stream (which is hard to do without)

if the carbohydrate capsule is loosely attached it is known as?

slime

how are carbohydrate capsules overcome or utilized in medicines?

polysaccharide vaccines and strain typing

what type of serology does a Gram - bacteria with a carbohydrate capsule give off?

HOK

(H-type of flagella, O-LPS part, K-capsule)

what is used to "stain" polysaccharide capsules

use India ink to stain the background (not the actual capsule)

flagella are composed of a polymerized protein called ______ which is recognized by the ______ ______

flagellin; immune system

what about the flagella of spirochetes (gr -) is unique

it is anchored in the periplasmic space (instead of wall)

pili/fimbriae are mainly present in gram - or +? flagella?

gram negative; both

major function of pili/fimbriae

attachment to surfaces and cells

the pili/fimbriae are the main virulance factor for which bacteria

escherichias (ie E. coli)

how are fungi cell walls different?

lack peptidoglycan and contains chitin