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Microbiology
Chapter 4- Tortora
77
Microbiology
Undergraduate 1
09/07/2011

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Term
Prokaryotes Characteristics
Definition
1. Their DNA is not enclosed within a membrane.
2. Their DNA is not associatedd w/ histones other proteins are associated w/the DNA
3. They lack membrane-enclosed organelles.
4. Thier cell walls almost always contain the complez polysaccharide peptidoglycan
5. The usually divide by binarry fission.

OR

-one circular chromosome NOT in a membrane
- no histones
-no organelles
-Peptidoglycan cell walls if bacteria
- Psedomurien cell walls if archaea
Term
Binary Fission-
Definition
DNA is copied and the cell splits into 2 cells. Involved fewer structures and processes than eukaryotic cell division.
Term
Eukaryotes Characteristics
Definition
1. Their DNA is found in the cell's nucleaus, which is seperated from the cytoplasm by a nuclear membrane and the DNA is found in multiple chromosomes.
2. Their DNA is associated w/ chromosomal proteins called histones.
3. They have a number of membrane enclosed organelles.
4. Their cell walls are simple, chemically.
5. Cell division usually involves mitosis, in which chromosomes replicate and an i dentical set is distributed in each nuclei.
Term
Diplococci
Definition
cocci that remain in pairs
Term
Streptococci
Definition
Cocci that remain in a chainlike pattern
Term
Tetrads
Definition
Cocci that divide in two planes and remain in groups of 4
Term
Sarcinae
Definition
Cocci that divide in 3 planes and reamin attached in cubelike groups of eight.
Term
Diplobacilli
Definition
Bacilli that appears in pairs after division
Term
Streptobacilli
Definition
Baccilli that occurs in chains.
Term
Vibrios
Definition
Bacteria that look like curved rods.
Term
Spirilla
Definition
have a helical shape, like a corkscrew and fairly rigid bodies.
Term
Monomorphic
Definition
bacteria that maintains a single shape
Term
pleomorphic
Definition
Bacteria that has many shapes
Term
Glycocalyx
Definition
a general term used for substances that surround cells
- sugar coating outside of the cell wall
Term
Capsule
Definition
if the substance surrounding a cell is organized and firmly attached to the cell wall,it is ...
Term
Slime layer
Definition
if the substance is unorganized and only loosely attached to the cell wall, it is known as...
Term
Flagella
Definition
long filamentous appendages that propel bacteria.
Term
Atirchous
Definition
bacteria that lack flagella
Term
Peritrichous
Definition
flagella is distributed all over the cell
Term
Polar
Definition
Flagella that is at one or both poles or ends of the cell. Flagella will also be monotrichous (one pole)
Term
Average size of prokaryotic cells
Definition
.2- 1.0 micrometer x 2-8
Term
Basal bodie
Definition
anchors the flagella to the cell wall and plasma membrane, composed of 2 small central rod inserted into a serie of rings
Term
Gram- Negative Bacteria....
Definition
contains 2 pairs of rings, the outer pair of rings is anchored to various portions of the cells wall.. The inner pair of rings is anchored to the plasma membrane.
Term
Gram- Positive Bacteria-
Definition
only the inner pair of rings are present.
Term
Gram- Positive Bacteria-
Definition
only the inner pair of rings are present.
Term
Taxis
Definition
The movement of bacterium toward and away from a particular stimulus
Term
H-antigen
Definition
a flagellar protein, useful for distinguishing among serovars, or variations within a species, of gram-negative bacteria.
Term
Axial Filaments or endoflagella
Definition
bundles of fibrils that arise at the ends of the cell beneath an outer sheath and spiral around the cell.
Term
Pili
Definition
involved in motility and DNA transfer.
Term
Gliding Motility
Definition
smooth gliding movement of myxobacteria
Term
Twitching motility
Definition
a pilus extends by the addition of subunits of pilin, makes contact with another cells and then retracts.
Term
The Cell wall
Definition
...of the bacterial cell is a complex, semirigid structure responsible for the shape of the cell.
Term
Peptidoglycan
Definition
the bacterial cell wall is composed of a macromolecular network.
Term
lysis
Definition
destruction caused by the rupture of the plsma membrand and the loss of cytoplasm
Term
Describe gram-positive bacteria walls
Definition
the cell wall consist of many layers of peptidoglycan, forming thick rigid structures
Term
Describe gram-negative walls
Definition
contain only a thin layer of peptioglycan, consist of lipopolysaccarides (LPS) lipoproteins, and phospholipids.
Term
Porins
Definition
part of the permability of the outer membrame is due to proteins in the membrane.
- they also permit the passage of molecules such as nucleotides, disaccharides, peptides, amino acids, b12 and iron.
Term
Lipopolysaccharide (LPS)
Definition
the outer membrane is a large complex that contains lipids and carbohydrates and consists of 3 components:
1. Lipid A
2. Core Polysaccliaride
3. O Polysaccaharide.
Term
Lipid A
Definition
A lipid portion of the LPS and is embedded in the top layer of the outer membrane.
_____ is released when the gram negative bacteria dies.
Term
mycolic acid
Definition
hydrophobic waxy lipid in their cell wall that prevents uptake of dyes .
Term
Protoplast
Definition
wall-less cell, spherical and still capable of carrying on metabolism
Term
L Forms
Definition
Proteus, as well as other genera, can lose their cell walls and swell into irregularly shaped cells.
Term
Osmotic Lysis
Definition
Protoplasts and spheroplasts burst in pure water or dilute sugar or salt solutions becuase the water molecules from the surrounding fluid rapidly move into and enlarge the cell. This rupturing is called ------
Term
Plasma (cytoplasmic) Membrane
Definition
a thin structure lying inside the cell wall and enclosing the cytoplasm of the cell.
- consist primarily of phospholipids (most abundant chemicals in the membrane, and proteins)
- Phospholipid Bi layer
-peripheral proteins
- intergral proteins
-Transmembrane
-Proteins
Term
glycoproteins
Definition
proteins attached to carbohydrates
Term
glcolipids
Definition
lipids attached to carbohydrates
Term
spheroplast
Definition
a wall less gram positive cell. susceptible to osmotic lysis
Term
Fluid mosaic model
Definition
-Membrane is as viscous as olive oil
-Proteins move to function
-Phospholipids rotate and move laterally
Term
Selectively Permeability
Definition
Allows passage of some molecules.
- Indicates that certain molecules and ions pass through but that others are prevented from passing through.
Term
Chromatophores
Definition
Membrane structures that are in some bacteria, pigemnts and enzymes involved in photosynthesis are found in infoldings of the plasma membrane that extend into the cytoplasm
Term
Simple Diffusion
Definition
the movement of molecules or ions from an area of HIGH concentration to an area of LOW Concentration. Movement continues until molecules or ions are evenly distributed.
Term
Facilitated Diffusion
Definition
integral membrane proteins function as channels or carriers that facilitate movement of ions or large molecules across the plasma membrane.

- Solute combines with a transporter protein in the membrane.

It is similar to simple diffusion however the cell does NOT expend enrgy.
Term
Osmosis
Definition
The movement of water across a selectively permeable membrane from an area of high water to an area of lower water concentration.
Term
Osmotic Pressure
Definition
the pressure required to prevent the movement of pure water (water with no solutes) into a solution containing some solutes.
Term
Isotonic Solution
Definition
a medium in which the overall concentration of solutes equals that found inside a cell.
Term
Water leaves and
Definition
enters the cell at the same rate (no net change)
Term
Hypotonic solution
Definition
outside the cell is a medium whose concentration of solutes is lower than that inside the cell
Term
hypertonic solution
Definition
a medium having a higher concentration of solutes than inside the cell has.
Term
active transport
Definition
the cell usues energy in the form of ATP to move substances across the plasma membrane
Term
group translocation
Definition
a special form of active transport that occurs exclusivley in prokaryotes, the substance is chemicalled altered during trnasport across the membrane
Term
cytoplasm
Definition
the substance of the cell inside the plasma membrane
Term
Plasmids
Definition
bacteria often contains small usually circular double stranded DNA molecules

They are not connected to the main bacterial chromosomes and they replicate independently of chromosomal DNA.

Contain 5-100 genes that are not crucial for the surviaval of the bacterium .
Term
Ribosomes
Definition
Are contained in all eukaryotic and prokaryotic cells. Functions at the sites of protein synthesis.
Term
Name for Prokaryotic Ribosomes
Definition
70S (smaller and less dense)
Term
Name for Eukaryotic Ribosomes
Definition
80S
Term
What does the S in 70S and 80S refer to?
Definition
The Letter S refers to Svedberg units, which indicate the relative rate of sedimentation during ultra-high-speed centrifugration ( Rate at which Ribosomes will settle)
Term
Inconclusions
Definition
Within the cytoplasm of prokaryotic cells are several kinds of reserve deposits called...
Term
Endospores
Definition
When essential nutrients are depleted, certain gram-positive bacteria, such as those of the genera form specialized "resting" cells.
Term
Germination
Definition
An endospore returns to its vergetative state by a process called _____. It is triggered by physical or chemical damage to the endospore's coat.
Term
Flagella
Definition
projections are few and are long in relation to the size of the cell
Term
Cilia
Definition
projections are numberous and short they are called ____
Term
Microtubles
Definition
_______ are long hollow tubes made up of a protein.
Term
glycocalyx
Definition
In eukaryotic cells, including animal cells, the plasma membrane is covered by _______, a layer of material containing substantial amounts of sticky carbohydrates.
Term
cytoplasm membrane
Definition
substance inside plasma and outside nucleaus
Term
Cytosol
Definition
Fluid portion of cytoplasm
Term
Cytoskeleton
Definition
provides support and shape and assists in transporting substances therough the cell.
Term
Cytoplasmic streaming
Definition
the movement of eukaryotic cytoplasm from one part of the cell to another, which helps distribute nutrients and move the cell over a surface.
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