Microbio- Ch. 3

Front 1

Filamentous Appendages

Back 1

Composed of protein subunits that form a helical chain.

Front 2

Flagella

Back 2

Provides the most common mechanism of motility.

Front 3

Pili

Back 3

Extracellular. Multiple forms and functions. Allow cells to:

-Adhere to surfaces.

-Exchange genetic info ("sex").

-Be motile.

Front 4

Capsule

Back 4

Made of polysaccharide. Distinct and gelatinous. Allows bacteria to adhere to specific surfaces. Allows some bacteria to evade immune defense mechanisms and thus cause disease (pathogenicity).

Front 5

Slime Layer

Back 5

Diffuse and irregular. Allows bacteria to adhere to specific surfaces.

Front 6

Cell Wall

Back 6

PG. Provides rigidity to bacterial cell walls, preventing cells from lysing.

Front 7

Gram Positive

Back 7

Thick PG layer containing teichoic acids and lipoteichoic acids.

Front 8

Gram Negative

Back 8

Thin PG layer surrounded by an outer membrane. The outer membrane is composed of lipolysaccharide.

Front 9

Cytoplasmic Membrane

Back 9

Phospholipid bilayer embedded with proteins. Surrounds the cytoplasm. Separating it from the outside environment. Also transmits external environment info to inner cell.

Front 10

DNA

Back 10

Contains the genetic information of the cell.

Front 11

Chromosomal DNA

Back 11

Carries genetic info REQUIRED by the cell. Typically a double stranded DNA molecule.

Front 12

Plasmid DNA

Back 12

Extra-chromosomal circular DNA molecules. Generally carries extra genetic info that is only advantageous to the cell in certain situations.

Front 13

Endospore

Back 13

Dormant cell. Generally extraordinarily resistant to:

-heat

-toxins

-UV radiation

-dessication

Front 14

Cytoskeleton

Back 14

Involved in cell reproduction. Holds cell shape.

Front 15

Gas vesicles

Back 15

Small rigid structures that provide buoyancy to the cell.

Front 16

Granules

Back 16

Accumulations of high molecular weight polymers, synthesized from a nutrient available in relative excess.

Front 17

Ribosomes

Back 17

Involved in protein synthesis. 2 subunits: 30S and 50S. Join together to form the 70S ribosome.

Front 18

Myxobacteria

Back 18

-travel in packs

-release enzymes and break down organic materials as a swarm

-have fruiting bodies that are visible to the human eye when in unfavorable conditions

Front 19

Negative Staining

Back 19

-acidic

-burns up specimen and leaves on image on the dark background

Front 20

Simple Stains

Back 20

-basic dye

-easy contrast increase on transparent backgrounds

-non-differential

Front 21

Aquaporin

Back 21

Membraneous pore proteins that specifically allow water molecules through the cells membrane.

Front 22

Differential Stains

Back 22

Stain methods that stain specific cells different ways, making them easier to identify.

2 types:

-Gram Staining

-Acid-fast Staining

Front 23

Gram Staining

Back 23

Identifies two types of cells:

-Gram Positive (Purple)

-Gram Negative (Pink)

Front 24

Gram Positive

Back 24

-Purple

-Thick peptidoglycan layer

Front 25

Gram Negative

Back 25

-Pink

-Thin peptidoglycan layer

-Perriplasm

Front 26

Periplasm

Back 26

Gel-like material that fills the region between the cytoplasmic membrane and the outer membrane of Gram Negative bacteria.

Front 27

Transport Systems

Back 27

Protein mechanisms that transport nutrients and other small molecules across the cytoplasmic membrane.

*chemicals that interfere with transport systems unique to certain (prokaryotic) cells can be used to selectively destroy those cells without harming human cells that lack the same specifically targeted transport system.

Front 28

Prokaryotic Cells

Back 28

-smaller than eukaryotic cells

-high SA:V ratio, making it easier to divide and thus reproduce.

-vulnerable to:

____-predators

____-parasites

____-competitors

such disadvantages encouraged them to evolve unique features to cope

Front 29

Eukaryotic Cells

Back 29

-more complex

-most cellular processes take place in membrane bound environments (organelles).

-Have nuclei

Front 30

Light Microscope

Back 30

-(1000x)

-easy to observe cells

Front 31

Electron Microscopes

Back 31

-use electrons instead of light to produce the magnified image

-(100,000x)

-2 types:

____-Transmission

____-Scanning

Front 32

Electron Transmission Microscopes

Back 32

-beam of electrons THROUGH specimen

-elaborate preparation

Front 33

Electron Scanning Microscopes

Back 33

-beam of electrons scans back and forth OVER specimen

-High surface detail

-3-D effect

Front 34

Atomic Force Microscopes

Back 34

-Produce images of individual atoms

-an ultra sensitive probe senses even the slightest movements in the sample.

-produces a map showing bumps and valleys of the atoms on the surface of the specimen

Front 35

Bright Field Microscopy

Back 35

-Illuminates field of view evenly

-most common

Front 36

Dark Field Microscopy

Back 36

-light is directed towards the specimen at an angle

-unstained cells easier to see

-organisms bright against dark background

-Treponima pallidum (Syphilis)

Front 37

Phase Contrast Microscopy

Back 37

-increases contrast by amplifying differences in the refractive index.

-makes unstained cells easier to spot

-Paramecium bursaria (green algae symbiont)

Front 38

Differential Interference Contrast Microscopy

Back 38

-2 light beams pass through specimen and then recombine

-image appears to be 3-D

Front 39

Refractive Index

Back 39

-Measure of the relative speed of light (c) as it passes through a medium

Front 40

Contrast

Back 40

-affects ease of visibility

Front 41

Capsule Stains

Back 41

-negative stains for viscous capsules that don't take up certain stains

-BG stained