Microbiology, Bio 221, BYUI

cell membrane

lipid bilayer, proteins, carb, and lack steroids in plasma membrane of prokaryotic cells

Prokaryotes

lack membrane bound organelles, and DNA are single circular with no histones; no sterols in plasma membrane

Eukaryotes

have membrane bound organelles, and DNA are linear

Shapes of bacteria

Cocci, Baccilli, Spiral (Vibrio, Spirilla, Spirochete)

Vibrio

form a bow shape

Spirilla

helical shape that is rigid; 2-3 curves

Spinochete

helical shape that is flexible; 3-4+ curves

Four basic types of flagella arrangements:

Peritrichous, Monotrichous, Lophotrichous, and Amphitrichous

Monotrichous (& Polar)

One flagellum at one pole

Peritrichous

flagella all over cell

Lophotrichous (& Polar)

tuft of flagella at one pole

Amphitrichous (& Polar)

flagella at both poles of the cell

Atrichous

bacteria that lack flagella

Axial Filaments

- Only found in spirochetes

- Rotation causes cell to move like a corkscrew

- Axial filament located between the outer sheath and the cell wall

Fimbriae (fimbra1)

hairlike appendages made of pilin; used for attachment and colonization of host

Pili

Made of pilin and form a single long shaft connecting two bacteria together; to exchange DNA between bacteria

Glycocalyx

-Capsule when substance is composed, organized, and attached to cell wall and thick

-Slime layer if only loosely attached to cell wall and thin

-Polymer of polysaccharide and protein found on outside of cell wall

Cell Wall

2 Types - Gram+ and Gram-

Components include:

-peptidoglycans

-peptides and proteins

-phospholipids

-polysaccharides

Plasma membrane is under cell wall

Gram positive

-Describing the group of bacteria that have a cell wall that is structurally less complex and contains more peptidoglycan than the cell wall of gram-negative bacteria. Gram-positive bacteria are usually less toxic than gram-negative bacteria.

-Contain Teichoic Acid which is the main antigenic determinate for Gram+

Gram Negative

Describing the group of bacteria that have a cell wall that is structurally more complex and contains less peptidoglycan than the cell wall of gram-positive bacteria. Gram-negative bacteria are often more toxic than gram-positive bacteria

-NO Teichoic Acid

-Contain O Polysaccharide-main antigenic determinate (tail of mouse-behind)

-Contain LipidA - an endotoxin - very toxic (mouse behind imbedded in outer membrane)

How does penicillin work?

Interferes with final linking of peptidoglycan rows by peptide cross bridges.

Carbohydrate Backbone

NAG/NAM; Cross bridges bind to NAM

These antibiotics kill by binding the transpeptidase enzyme which attaches to the cross bridge, instead attaches to ___________ and causes the disruption of cellular intergrity.

Penicillin and Beta Lactam antibiotics

Where does lysozyme attack bacteria cell walls?

It attacks the peptidoglycans found in the cell walls, especially gram-positive bacteria.

What's teichoic acid doing in gram + cell walls?

It's an antigenic determinant; Helps provide structure

-composed of alcohol and phosphate

Gram Negative outer membrane function

Strong negative charge is an important factor in evading phagocytosis and the actions of complement, two components of the defenses of the host. The outer membrane also provides a barrier to certain antibiotics, digestive enzymes such as lysozyme, detergents, heavy metals, bile salts, and certain dyes.

periplasmic space

The space between the inner and outer cell membranes in Gram-negative bactera. The peptidoglycan cell wall is found in the periplasmic space, and this space sometimes contains enzymes to degrade antibiotics.

Porin Protein

-A type of protein in the outer membrane of gram-negative cell walls that permits the passage of small molecules; nutrients and waste pass through

2 TYPES

1) Integral - span and go whole way through plasma membrane; allow nutrients and waste products out

2) Peripheral Protein - only attach to one surface of plasma membrane; either inside or outside; act as an enzyme to speed up chemical reaction in cell

Lipoproteins

-connect outer membrane and plasma membrane

-make periplasmic space possible

Tetrapeptide Sidechains

-4 Amino Acids attached to NAM 's in the backbone

-Parellel tetrapeptide side chains may be directly bonded to each other or linked by a peptide crossbridge

Prokaryotic Flagella

-Filament- Composed of proteins called flagellin; form the long hairlike structure that sticks out of the cell (Not enclosed within the plasma membrane)

-Hook - wide structure that holds the filament and turns it like apropellar

-Basal Body - anchors flagellum to the cell wall and plasma membrane

Eukaryotic flagella

Membrane covering present on filament of flagella

Hook and only two rings attached to the plasma membrane

Wave-like motion

vacuole

stores materials such as water, salts, proteins, and carbohydrates

cilia

Only found in euks, are hairlike projections that extend from the plasma membrane and are used for locomotion

lysosomes

contains digestive enzymes

Mitochondria

ATP, Double membrane system, carry out the most efficient energy-releasing reactions, reactions require O2

Golgi complex

Put finishing touches on proteins and lipids that arrive from ER

Package for shipment to final destinations outside of cell - "Post office" - "Shipping and Receiving"

Material arrives and leaves in vesicles

nucleus

Keeps DNA separated from cytoplasm, Makes it easier to organize DNA, copy, before parent cells divide into daughter cells

Endoplasmic Reticulum

In animal cells, continous with nuclear membrane, extends throughout cytoplasm, rough one and smooth one

Smooth ER - Lipid synthesis

Rough ER - Protein synthesis

Chemotaxis

movement of a motile cell or organism, or part of one, in a direction corresponding to a gradient of increasing or decreasing concentration of a particular substance.

run and tumble

movement of flagelar bacteria; short runs interrupted by tumbles

Capsule

Thick, highly organized, and solidly fixed to the cell wall, these prevent the use of penicillin

pilin

-protein that makes up pili, which forms a single long shaft connecting two bacs together to exchange DNA

-Fimbriae are also composed of this

hypotonic

-Solution with lower solute concentration than inside of cell - water follows solutes

-Most bacteria are happy in hypotonic solution

lysozyme

an enzyme found in saliva and sweat and tears that destroys the cell walls of certain bacteria

active transport

the movement of materials through a cell membrane using energy

CV-I complex

the __ is too large to pass through the thick cell wall of gram positive cells

Steptococcus Pyogenes

Cocci

Positive

Strep throat

Staphlyoccus aureus

Cocci

Positive

Food poisoning

Escherichia coli

Bacilli

Negative

Urinary tract infection

Clostridium botulinum

Bacilli

Positive

Food poisoning

Bacillus anthracis

Bacilli

Positive

Anthrax

Neisseria meningitidis

Cocci

Negative

Meningitidis

Vibrio cholerae

Vibrio

Negative

Cholera

Borrelia burgdorferi

Spirochete

Negative

Lyme Disease

Mycobacterium tuberculosis

Bacilli

Positive

Tuberculosis

Yersihia pestis

Bacilli

Negative

Bubonic plague

Salmonella typhi

Bacilli

Negative

Typhoid fever

Troponema pallidum

Spiral

Negative

Syphilis

bacterial growth

increase in number of cells, not cell size; fission

bacterial growth requirements

physical and chemical

Simple Diffusion

Passive;

movement of molecules from areas of high concentration to low concentration

Facilitated diffusion

Passive;

Molecules combines with a plasma membrane proteins called transporter protein

Osmosis

passive

movement of WATER across a selectively permeable membrane

high concentration to low concentration

Plasmolysis

lysing of bacteria because water is drawn out in a hypertonic solution

isotonic solution

A solution in which the concentration of solutes is essentially equal to that of the cell which resides in the solution

No net movement

Hypertonic solution

water moves out of cell, causing its plasma membrane to shrink (plasmolysis)

Hypotonic solution

Water moves into a cell and may cause cell to burst if wall is weak or damaged (osmotic lysis)

Active Transport

cell uses energy (ATP) to move substance across plasma membrane

-moves substance from low concentration to high concentration

Group Translocation

Active process, occurring in some prokaryotes, by which a substance being actively transported across a cell membrane is chemically changed during transport.

-once substance is across the membrane, it is impermeable to the membrane

-Only in prokaryotes

Inclusion

Storage areas fro cells to store molecules and particles that they need (1-Gas vacuoles, 2-lipid inclusion, 3-polysaccharide granules, 4-metachromic granules which contain phosphate to be able to produce ATP in future, diptheria have metachromic inclusions)

Endospore

-"Resting cells"

-When an environment becomes unlivable, certain GRAM+ bacteria can form these resting structures

-Cell puts DNA inside endospore and thr est of the cell dies.

-Can survive for 10,000+ years; resistent to heat and toxins

2 Generra of endospore forming bacteria

1) Clostridium (tetanus and botulism)

2) Bacillus (Anthrax)

Vegatative cell

metabolically active form of bacterium in which reproduction can occur; NOT ENDOSPORE

Nuclear envelope (nuclear membrane)

-a lipid bilayer that surrounds the nucleus in eukaryotic cells

-Innermost surface has DNA attachment sites

-Pores span bilayer

Chromatin

-Cell's collection of DNA and associated proteins

-Chromosome is one DNA molecule and its associated proteins

-Appearance changes as cell divides

-DNA molecules are not wound up and are loose floating inside nucleas

Components of Cytomembrane System

1) Endoplasmic Reticulum- attached to nuclear envelope

2) Golgi Bodies

3) Vesicles - "bubble" off of ER and travel over to Golgi Bodies

Endoplasmic Reticulum

-continuous with nuclear membrane

-extends throughout cytoplasm

-two regions - Rough and Smooth

Rough ER

-ER that is dotted with ribosomes

-Purpose is protein synthesis

Smooth ER

3 Functions:

1- Lipids assembled

2-Lipid synthesis

3-Inactivate toxic chemicals (liver cells have a lot of this=alcohol and tylenol are deactivated by smooth ER in liver

vesicles

-membranous sacs that move through the cytoplasm

-Lysosomes - contain digestive enzymes= break down old depleted parts of cells to components and then they are recycled

-Peroxisomes - Store things

Mitochondria

ATP producing "powerhouse"

require oxygen

Cytoskeleton

-Present in all eukaryotic cells

-Basis for cell shape and internal organization

-Allows organelle movement within cells and in some cases, cell motility

Cytoskeleton Elements

1) Microtubule- Thickest component; push and pull on membrane

2) Intermediate Filament - Next thickest; Not very flexible but is very STRONG

3) Microfilament - Smallest; extremely flexible; Not very strong

Psychophile

Cold Loving

Optimal Growth 15C

-Too cold to be pathogens

Psychotroph

Cold Loving

Optimal Growth 25C (which is room termperature)

-Can grow in body, but immune system will clear them out

Mesophile

Moderate temp loving

Optimal Growth 37C (which is body temperature)

-Include pathogens which are optimized for body temperature

Thermophile

Heat Loving

Optimal Growth 55C

-Can't grow inside body; "Hot Pots in Yellowstone"

Acidophiles

Grow in acidic environment less than 6.5

-linked to stomach ulcers

-Very few bacteria can grow below 4.0

=Many foods such as sauerkraut, pickles, and cheeses are preserved from spoilage by acids produced during fermentation

Osmotic Pressure Range

Low osmotic pressure kills many prokaryotes by plasmyolysis= Hypertonic solution

Halophiles

Microbes that can survive in salty environments

-bacteria function with Na pumps

Obligate Halophiles

Microbes that need salty environments to survive

Obligate Aerobes

must have free oxygen for aerobic respiration

-Neutralize O2

-living forms had to evolve to use O2

facultative anaerobes

Have both aerobic and anaerobic growth

-Growth is greater in the presence of oxygen because full respiration occurs

Aerotolerant anaerobes

Only anaerobic grown, but can tolerate the presence of oxygen

-Growth occurs evenly throughout media as oxygen as no effect

Halophiles

"salt-loving" archaea that live in environments that have very high salt concentrations

Microaerophiles

Only aerobic growth

-Oxygen is required in low concentrations

-Growth occurs only where a low concentration of oxygen has diffused into the medium

-growth is in center of medium

Obligate Anaerobes

Killed by free oxygen.

Growth only occurs where there is no oxygen

Nutritional Requirements for Growth

1) Carbon- all living things need a carbon source (usually a sugar-glucose, sucrose, fructose)

2) Nitrogen- used in protein and nucleic acid synthesis (Amino Acids are made because their is nitrogen)

3) Sulfur- Used in protein synthesis

4) Phosphorus- Used in ATP and nucleic acids

5) Trace Elements- (Fe, Zn, Cu, etc.) Co-factors and co-enzymes to activate enzymes

-Bind to enzymes to turn enzyme on or off

-Bacteria are "mining" for iron (Fe)

6) Organic Grown Factors- organic compounds that are essential to the organism but the organism is unable to synthesize it itself (EX: Vitamins ,amino acids, nucleotides)

Neutrophiles

Neutral environment pH 6.5-7.5

-Most pathogens are neutrophiles as human body is mostly within this pH range

-most bacteria that cause food spoilage grow between pH 6.5-7.5