Microbiology: Chapter#4 Functional anatomy of prokaryotic and eukaryotic cells.

Bacterial growth patterns:

1) Diplococci: appears in pairs after division. 2) streptococcus:divide but remain attached in a chain like pattern 3) staphyloccus: they divide in multiple planes and form "grape like clusters" or broad sheets. 4) tetrads: they divide in two planes but remain in groups of "four"(4) 5) sarcinae: they divide in two planes and remain attached in "cube like groups" of eight 8.

Flagella

1) outside the cell wall 2) made of chains of flagellin (protein). attached to a protein hook 3) shaft runs between the hook and the basal body, passing through protein rings in the cell's membrane that acts as bearings.

Describe structure of Gram negative cell walls

1) thin peptidoglycan 2) outer membrane 3) pepriplasmic space Outer membrane: protection from phagocytes, complement and antibodies. O-polysaccharide antigen Lipid A is an endotoxin

EPS extracellular polymeric substance

A glycocalyx within the bio-film attach to their target environment and to each other. the EPS protects the cell within, facilitates communication among the cells, and enables the cells to survive by attaching to various in the natural environment.

Isotonic solution

A medium in which the over all concentration of solutes equals that found inside a cell.

explain why the capsule is antigenic

In certain species, capsules are important in contributing to bacterial virulence (the degree to which a pathogen causes disease). Capsules often protect pathogenic bacteria from phagocytosis by the cells of the host.

Glycocalyx

It means sugar coat, a viscous "sticky" gelatinous polymer that is external to the cell wall and composed of polysaccharide, polypeptide, or both.

Distinguish between monomorphic shape.

Monomorphic: bacteria that maintains a single shape.

Distinguish between pleomorphic shape.

Pleomorphic: they have many shapes not just one.

Thylakoids

a chlorophyll containing membrane in a chloroplast, a bacterial thylakoid is known as a "chromatophore".

Cell Capsule

a very large structure of some prokaryotic cells found in both gram positive and gram negative cells. Its a polysaccharide layer that lies outside the cell envelope and deemed part of the outer envelope of a bacterial cell. Well organized layer not easily washed off and it an be the cause of "various diseases".

Identify spheroplast

a wall less gram positive cell. Its susceptible to "osmotic lysis".

Ribosomes

all eurkaryotic and prokaryotic cells have them, its where protein synthesis takes place. prokaryotic ribosomes in the number of proteins and rRNA molecules they contain they are somewhat smaller and less dense than ribosomes.

Basal body

anchors the flagellum to the cell wall and plasma membrane, the basal body is composed of a small central rod inserted into a series of rings. Gram-negative bacteria contains two pairs of rings; the outer ring is anchored to various portions of the cell wall and the inner pair of rings is anchored to the plasma membrane. Gram-positive only the inner pair is present.

Identify L forms

are wall less cells that swell into irregular shapes

Atrichous

bacteria that lack a flagella

Basic shapes of vibrio

bacteria that looks like curved rods

Cell wall structure of peptidoglycan

bacterial cell wall is composed of a macro molecular network which is present either along or in combination with other substances. It consists of repeating disaccharide connected by polypeptides to form a lattice that surrounds and protects the entire cell. The disaccharide portion is made up of monosaccharides called "N-acetylglucosamine NAG and N-acetylmauramic acid NAM, which are related to glucose".

Plasmids

bacterial chromosomes often contain small usually circular double stranded DNA molecules. These chromosomal genetic elements that is they are not connected to the main bacterial chromosome and they replicate independently of chromosomal DNA. they carry genes that are antibiotic resistance, tolerance to toxic metals, the production of toxins and synthesis of enzymes.

Axial filaments/Endoflagella

bundles of fibrils that arise at the ends of the cell beneath an outer sheath and spiral around.

Hook

consisting of a different protein

Lysozyme

digest disaccharide in peptidoglycan Penicillin inhibits pepditde bridges in peptidoglycan.

what are the various structures associated with the flagella?

filament, hook and, basal body.

Peritrichous

flagella distributed over the entire bacteria cell

Inclusions

found within the cytoplasm of prokaryotic cells, its used as a reservoir to store food. Some inclusions such as magnetosomes are membrane enclosed organells, while other inclusions such as carboxysomes are enclosed in protein complexes. Lipid inclusions: energy reserves sulfur granules: energy reserves gas vacuoles: protein covered cylinders magnetosomes: iron oxide (destroys H2O2) polysaccharide granules: energy reserves metachromatic granules (volutin): phosphate reserves.

Slime layer

glycocalyx that's unorganized and only loosely attached to the cell wall.

Fimbriae

have a tendency to adhere to each other and , to surfaces its a result forming of "biofilms" and other aggregations on the surface of liquids, glass and rocks; adhesion too epithelial surfaces in the body.

Basic shapes of spirillium

helical shaped like a corkscrew and fairly rigid bodies they have "flagella" to move.

facilitated diffusion

integral membrane proteins function as channels or carriers that facilitates the movements of ions or large molecules across the plasma membrane.

Pili

involved in motility and DNA transfer.

Hypertonic solution

is a medium having a higher concentration of solutes than that inside the cell.

Identify protoplast

is a wall less cell, Its susceptible to "osmotic lysis".

Describe the structure of glycolipids

lipids attached to carbohydrate It helps protects and lubricates the cells and are involved in cell to cell interactions.

Lipoteichoic acid Teichoic

made up of alchols such as glycerol or ribitol and phosphate. has a peptidoglycan layer.

simple diffusion

movement of molecules or ions from an area of higher concentrations to an area of low concentrations

Osmosis

movement of water across a selectively permeable membrane from an area of high water to lower area water concentration

Hypotonic solution

outside the cell is a medium whose concentrations of solutes is lower then that inside the cell.

Basic shapes of coccobacilli

oval shaped looks like cocci

Describe the structure of the plasma membrane

phospholipid bilayer peripheral proteins integral proteins transmembrane proteins

Describe the structure of glycoprotein

proteins attached to carbohydrates. It helps protects and lubricates the cells and are involved in cell to cell interactions. Influenza virus and toxins caused by cholera and botulism enter their target cells by first binding to glycoproteins on their plasma membranes.

Porins

proteins form channels through the membrane of a gram negative cell wall. It permits the passage of molecules such as nucleotides, disacchride, peptides, amino acids, Vitamin B12 and Iron

Endospores

resting cells they provide resistance to high heat, lack of nutrients, desiccation, radiation, chemicals and disinfectants. Sporulation- endospore formations Germination- return to vegetative state

Basic shapes of bacillus.

rod shaped (meaning little rods or walking sticks).

Monoperitrichous

single fagellum at one pole

Conjugation (sex) pili

some pili are used to bring bacteria together allowing the transfer of DNA from one cell to another.

Basic shapes of coccus.

spherical shaped (meaning berries).

Basic shapes of spirochetes

spiral and flexiable worm like.

Motility

the ability of an organism to move by itself.

what part of the flagella is antigenic?

the flagellar protein called H-antigen is useful for distinguishing among "serovars" or variations within a species of gram-negative bacteria.

Filament

the long outer most region,is constant in diameter and contains the globular (roughly spherical) protein flagellin arranged in several chains that intertwine and form a helix around a hollow core.

Cell wall

the major functions is to prevent cells from rupturing when the water pressure inside the cell is greater then that outside the cell. Clinically the bacterium cell wall is important because it contributes to the ability of some species to cause disease and its the site of actions of some antibiotics.

LPS lipopolysaccharide

the outer membrane of the gram-negative cell consists of lipoproteins, and phospholipids. Its also an outer membrane which is a large complex molecule that contains lipids and carbohydrates and consists of three components (1) Lipid A, (2) a core polysaccharide, and (3) an O polysaccharide. Lipid A: is the lipid portion of the LPS and is embedded in the top layer of the outer membrane, when gram-negative bacteria die they release lipid A, which functions as an endotoxin. Core polysaccharide: is attached to lipid A and contains unusual sugars, its role is structural to provide stability. O polysaccharide: extends outward from the core polysaccharide and is composed of sugar molecules. The o polysaccharide functions as an "antigen" and is useful for distinguishing species of gram-negative bacteria.

Osmotic pressure

the pressure needed to stop the movement of water across the membrane

what accounts for the various growth patterns?

the shape of a bacterium is determined by heredity, however a number of environmental conditions can alter that shape.

Cell wall structure of polypeptides

the structure of the polypeptide link varies, it always includes tetrapiptide side chains, which consist of four amino acid attached to NAMs in the backbone. The amino acid occur in an alternating pattern of D and L forms.

Describe structure of Gram positive cell walls

thick peptidoglycan teichoic acids adds ridgidity to cell walls attracts cations.

Amphitrichous

tuft of flagella at both poles of the cells

Lophotrichous

tuft of flagella coming from one pole

Peptidoglycan/Murein

which is present either along or in combination with other substances. Its repeating disaccharide connected by polypeptides to form a lattice that surrounds and protects the cell. N-acetylmuramic (NAM) N-acetylgulcosamine(NAG) related to glucose, the disacchride portion's made up of monosacchride.