Microbiology chapter 3

Cell

is the simplest structural unit of a living organism

cell doeswhat

is a living compartment enclosed in a membrane that interacts with the enviorment and other cell

What does living mean

Growth, Reproduction, Responsiveness, and Metabolism.

Growth

increase in size

Reproduction

increase in number

Responsiveness

ability to interact with enviromental stimuli

Metabolism

controlled chemical reactions of an organism

Cellular structure

membrane bound structure capable of all the above functions

Growth, Reproduction, Resposiveness, and Metabolism, and Cell Structure is present in what?

Bacteria, Archea, Eurkocytes

Viruses (Growth)

does not occur

Viruses (Reproduction)

host replicates the virus

Viruses (Responsiveness)

Reaction to the host cell seen in some viruses

Viruses (Metabolism)

Viruses uses the host cell' metabolism.

Viruses (Cellular structure)

viruses lack cytoplasmic membrane or cellular structure.

Prokarocytes

Bacteria and Anchae

No membrane enclosed organelles

No nucleus

Prokarocyte means in greek

before the nucleus

Eukarocytes

-Plants, animals, algae, protozoa, and fungi

Contain membrane bound organelles.

DNA enclosed in the membrane bound Nucleus.

Eukarocyte means in greek

True Nucleus

Cytoplasmic cell membrane

Barrier that seperates the inside of the cell from outside enviroment.

Cytoplasm

aqueous mixture of marcomolecules, small organic ions, and ribsomes inside the cell

Ribsomes

protein synthesizing stuctures.

DNA Genome

complement the gentic material of the cell.

Cell wall

present in microbes; confers structual strength

Exeternal structure of Bacteria Cells

enables cells to respond to other cells and their enviroment

Bacterial external structures include

Glyocalyces, Flagella, Fimbriae, and Pili

Glycocalyx

Gelantionous sticky substance sorrounds outside of the cell.

Glycocalyx roles

-Protects outside of the cell from drying.

-Can play a role in the ability of pathogens to survive and cause disease.

Two Types of Glycocalyes

Capsule and Slime Layer

Capsule

composed of organized repeating untis of organic chemicals.

-Firmly attattched to cell surface

-May prevents bacteria from being recongized from the host.

Slim Layer

-Loosely attatched to cell surface.

-Water soluble.

-Sticky layer allows prokaryotes to attatch to the surface.

Flagella Function

Responsible for movement

Flagella characterstics

-Rotation propels bacterium through it’s enviorment.

-Long strucutre that extends beyond the cell surface and glycocalyx

-Not present in all bacteria.

Flagella’s ____ moves in response to?

Bacteria, Stimuli

Flagella’s rotation

reversible can be counterclockwise or clockwise

When Flagella moves it moves how

running or tumbling

flagella structure

composed of filament, hook, and basal body.

Flagella's basal body

anchors the filament and hook to the cell wall.

Fimbrae

sticky bristle like projections used by bacteria to stick to one another and to substances in enviroment.

Fimbrae size and length

It’s size is numerous and shorter than flagella

Fimbrae serves as important function in

biofilms

Pili

Also known as Conjuction Pili is special type of fimbrae transfers DNA from one cell to another.

Pili’s length

longer than fimbrae but shorter than flagella

Bacterial Cell Walls

Provides structure and shape and protects cells from osmotic forces.

Bacterial Cell can assist in what?

Assist in some cells in attatching to other cells or in resting to antimicrobal drugs.

Bacterial cell walls can target what

can tagret cell wall of bacteria with antibiotics

Bacteria cell wallls are composed of

peptidoglycan

Peptidoglycan

a mesh like complex polysaccharide.

Two Basic Types of Bacterial Cell Walls

Gram Positive and Gram Negative

Gram Positive’s layer of Peptidoglycan

has a thick layer of peptidoglycan

Gram Positive consists of what chemicals

teichoic acids and lipoteichoic acids

Gram Positive appears what color during Gram Staining

appear purple during gram staining

Gram Positive uses what to survive desication

Uses up to 60% mycolic acid in acid fast bacteria helps cells survive dessication (dryness)

Gram Negative’s peptidoglycan

Has a thin layer of peptidoglycan

Bilayer of Gram negative

outside of the peptidoglycan contains phosolipids, proteins, and lipopolysaccharides.

Gram Negative’s Lipid A portion of polysaccharides

can cause fever, vasodilation, inflammation, shock, and bloodclotting.

Gram Negative’s outer membrane

can impeded the treatment of disease

Gram Negative gram staining

appers pink during gram staining

Bacteria without cell walls

Often mistaken for viruses due to small size and lack of cell wall.

Has other features of prokaryotic cells such as ribsomes.

Bacterial Cytoplasm Membrane also known as

Phospholipid Bilayer

Bacterial Cytoplasm Membrane composed of

Lipids and associated proteins

Bacterial Cytoplasm Membrane contains proteins such as

Integral proteins and peripheral proteins

In Bacterial Cytoplasm Membrane each phospholipid molecule is

bipolar

Fluid Mosiac Model

describes the current understanding of the Bacterial Cytoplasm membrane structure.

Bacteria Cytoplasmic Membrane’s permeability

It’s selectively permeable

Bacterial Cytoplasmic Membrane proteins’s role

Proteins allows substances to cross membrane

Bacteria Cytoplasmic membrane maintains

concentration and electrical gradient

Bacterial Cytoplasmic Membrane does what type of storage

Energy Storage

Bacterial Cytoplasmic Membrane harvests

light energy in photosythentic bacteria

Bacterial Cytoplasmic Membrane Passive Processes

Diffusion, Facilitated diffusion, Osmosis

Bacterial Cytoplasmic Membrane Active Processes

Active Transport and Group Translocation

Isotonic solution

the same

Hypertonic

The cell has higher concentration water goes out of the cell——> cell shrivels up

Hypotonic

Outside of the cell has a higher concentration water goes into the cell—> cell bursts.

Diffusion (simple def)

small or lipid solubles through the membrane

Faclitated diffusion (simple def)

several types of chemicals through non specific channel

Osmosis (simple def)

Diffusiomn of water through a channel or membrane

Unitransport

movement of one type of molecule in one direction

Simport

Moves two different molecules together in the same direction

Antiport

moves two different molecules in opposite directions

Coupled Transport

movement of molecule down concentration grandient provides energty to move another molecules against concentration gradient

Passive Transport Processes

Processes that requires no use of energy by the cell; electrochemical gradient provides energy

Diffusion (Transport Processes of Bacterial Cytoplasmic Membrane)

molecules move down their electrochemical gradient through the phosoplipid bilayer of the membrane

Ex Transported Substances: Diffusion

Oxygen, Carbon Dioxide, and Lipid Soluble Chemicals

Faciliated Diffusion (Transport Processes of Bacterial Cytoplasmic Membrane)

Molecules move down their own electrochemical gradients through channels or carrier proteins.

Facilated Diffusion Ex:

Glucose, Urea, and some Vitamins

Osmosis (Transport Processes of Bacterial Cytoplasmic Membrane)

moves down own their own concentration gradient across a selectively permeamble membrane

Osmosis ex

Water

Active Transport Processes

cells expends energy form of ATP to move substances move against electrochemical gradient.

Active Transport

ATP dependent carrier proteins bring substances into cell

Active Transport Ex:

NA, H, K, CA CL

Group Translocation

the substance chemically alterted during transport

Group Translocation ex:

glucose, mannose, and fructose