65a intro to microbio

Question 1

Mycology

Answer 1

study of fungi

Question 2

What type of cells are bacteria

Answer 2

Prokaryotic - No membrane bound organelles

Question 3

Spherical bacteria

Answer 3

Cocci

Question 4

Elongated bacteria shape

Answer 4

Rod shaped (bacilli)

Question 5

Short rods that sometimes appear to be spherical

Answer 5

coccobacilli

Question 6

Spiral Shaped

Answer 6

Spirochetes

Question 7

Cell envelope

Answer 7

All bacteria have a cell envelope, repsonsible for protecting the bacterium from enviromental threats and for housing factors important for cellular functions. Consists of Cytoplasmic membrane and cell wall

Question 8

Cytoplasmic membranes in bacteria

Answer 8

No sterols. Thy may contain proteins important for cellular functions: ETC, biosynth of cell wall components, partition of newly replicated chromosomes into daughter cells during cell division.

Question 9

Murein

Answer 9

Unique component of bacterial cell walls made of peptidoglycan. This gives the bacteria their characteristic shape and protects the cells against lytic injury. Peptidoglycan assembly is the target of several important antibiotics.

Question 10

Murien components

Answer 10

Long polymers of two alternating sugars:

1. N acetylmuramic acid (NAM)
2. N - acetylglucosamine (NAG)

May vary between different types of bacteria.

Question 11

Penicillin binding proteins

Answer 11

(PBPs) responsbile forproper cross linking of the acid side chains, attractive targets for antibiotics, namely penicillin.

Question 12

Gram staining

Answer 12

Refers to the ability of the cell wall to reatin dye.
Negative: Thin cell wall
Positive: Thick cell wall

Question 13

Other types of staining

Answer 13

Acid Fast, Ziehl - Neelson, Kinyoun

Question 14

Select spirochete staining

Answer 14

Some spirochetes have cell walls that are so thin that they have to bevisualized by dark field microscopy.

Question 15

Techoic acids

Answer 15

Long polyemers of either glycerol phosphate or ribitol phosphate that also contains sugars and amino acids. These are either attached to the cell wall itself or to the cell membrane (lipotechoic acids)

Question 16

Lipotechoic acids

Answer 16

Techoic acids that are directly attached to the cell membrane

Question 17

Gram Negative Cell border

Answer 17

Two bilayer bilayers, the space i between is called the periplasm

Question 18

Periplasm

Answer 18

Space in between inner and outer membrane on Gram Negative Bacteria.

Question 19

Lipopolysaccharide

Answer 19

Elements that extend from the outer membrane of GP bacteria. Made up of Lipid A, Core Polysaccharide, and O antigen. LPS is extremely toxic to humans and is referrd to as endotoxin.

Question 20

Lipid A

Answer 20

A phosphorylated diglucosamine. This is the componenet embedded in the outer membrane, The toxic effects of LPS are from lipid A.

Question 21

Core Polysaccharide

Answer 21

Middle region attache to Lipid A

Question 22

O antigen

Answer 22

A polysaccharide consisting of repeated 3-5 sugars. Not present in all bacteria. WQhen present it is antigenic and allows sterotypiing of many bacteria.

Question 23

LPS in the plasma

Answer 23

Binds to a plasma protein (LPS biding protein), this complex goes on to interact with CD14 recepetors on Monocytes and macrophages. Activates TLR recptor

Question 24

TLR receptor

Answer 24

Activated by LPS-Biding protein complex. This results in prodcution of cytokines.