Microbiology Chapter 4: Cell structure and Function, Part One: prokaryotic cell

If the substance is unorganized and only loosely attached to the cell wall, the glycocalyx is described as...

A Slime layer

If the substance is organized and is firmly attached to the cell wall, the glycocalyx is described as...

A capsule - Presence can be found by using negative staining - Contribute to bacterial virulence ( the degree to which a pathogen causes diseases)

Substances that cross the membrane from an area of low concentration to high, needs ATP

Active Process

Flagella at both poles of the cell

Amphitrichous

Bacteria that lacks flagella are referred to as

Atrichous

What do spirochetes use to move?

Axial Filaments

How is the shape of bacteria determined?

By heredity

Eukaryotic plasma membranes consist of

Carbohydrates and sterols

Major function is to prevent bacterial cells from rupturing when the water pressure inside the cell is greater than that outside the cell

Cell Wall

what is important because it contributes to the ability of some species to cause disease and is the site of action of some antibiotics

Cell wall

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

Conjugated (sex) pili -horizontal gene transfer

Attached to lipid A and contains unusual sugars. Provides stability

Core Polysaccharide

Bacilli that appear in pairs after division

Diplobacilli

Cocci that remain in pairs after dividing

Diplococci

Is made up of 2 sugars called N-acetylglucosamine (NAG) and N-acetylmuramic (NAM).

Disaccharide portion of peptidoglycan

In ___________ _______, Integral membrane proteins function as channels that facilitate the movement of ions or large molecules across the plasma membrane. - Like a gate

Facilitated diffusion

Flagellum has three basic parts...

Filament, hook, and basal body

Can occur at the poles of the bacterial cell or can be evenly distributed over the entire surface of the cell. ( Range from few to several )

Fimbriae - Have a tendency to adhere to each other and to surfaces

Some prokaryotic cells have long appendages that propel bacteria called

Flagella -Hair-like bacteria -Has no microtubules

The dynamic arrangement of phospholipids and proteins is referred to as the ...

Fluid mosaic model

A prokaryotic inclusion for buoyancy compensation

Gas vacuoles

Is the general term used for substances that surround cells

Glycocalyx - Outer layer - has lots of sugar which causes the bacteria to clump together. - forms Biofilm

Structures external to the prokaryotic cell

Glycocalyx Flagella Axial Filaments Fimbriae Pili

Most prokaryotes secrete on their surface a substance called

Glycocalyx (means sugar coat)

Lipids attached to carbohydrates are called

Glycolipids

Proteins attached to carbohydrates are called

Glycoproteins

Consist of one or a very few layers of peptidogylcan and an outer membrane.

Gram-negative bacteria - Are pink in gram stain

Cell wall consist of many layers of peptidoglycan, forming a thick, rigid structure.

Gram-positive bacteria -Are purple in gram stain

A special from of active transport that occurs exclusively in prokaryotes, the substance is chemically altered during transport across the membrane.

Group translocation

A medium having a higher concentration of solutes than inside the cell has

Hypertonic Solution

Outside the cell is a medium whose concentration of solutes is lower that than that inside the cell

Hypotonic Solution

Is the lipid portion of the LPS and is embedded in the top layer if the outer membrane. Functions as an endotoxin

Lipid A -Responsible for the symptoms associated with gram negative bacteria

Bacteria that maintain a single shape are called

Monomorphic - Most bacteria are ^

Flagella with a single flagellum at one pole is called

Monotrichous

All bacteria of the genus Mycobacterium and pathogenic species of Nocardia contain high concentrations of a hydrophobic waxy lipid called ______, in their cell that prevents the uptake of dyes, including those in the Gram Stain.

Mycolic Acid - Not very common in bacteria

Members of which genus have no cell walls

Mycoplasma

The __________ of a bacterial cell usually contains a single long, continuous, and frequently circularly arranged thread of double-stranded DNA called Bacterial Chromosome.

Nucleoid

Major structures in the cytoplasm of prokaryotes include

Nucleoid, ribosomes, and inclusions

Functions as an antigen and is useful for distinguishing species of gram-negative bacteria

O Polysaccharide

The net movement of solvent molecules across a selectively permeable membrane from an area with a high concentration of solvent molecules to an area of low concentration of solvent molecules

Osmosis

The bacterial cell wall is composed of a macromolecular network called _____________, which is present either alone or in combination with other substances

Peptidoglycan -has amino acids and sugars - is found only in bacteria

Flagella that is distributed over the entire cell is called

Peritrichous

Prokaryotic plasma membranes consist of

Phospholipids and proteins

Longer than fimbriae and number only one to two per cell

Pili - Involved in motility and DNA transfer

Inner Membrane, is a thin structure lying inside the cell wall and enclosing the cytoplasm of the cell

Plasma (cytoplasmic) membrane

-Bacteria that can have many shapes, not just one are called - Formed based on environment, might shrink or expand

Pleomorphic

Bacillus

Rod-Like

Coccus

Spherical

Bacteria that has one or more twist; never straight

Spiral

Spiral

Spiral

Spiral Bacteria that has a helical shape, like a corkscrew, and fairly rigid bodies

Spirilla

Group of Spirals that are helical and flexible

Spirochetes

The process of spore and endospore formation

Sporulation or sporogenesis

Cocci that divide in multiple planes and form grapelike clusters or broad sheets

Staphylococci

Bacilli that occurs in chains

Streptobacilli

Cocci that remain attached in chainlike patterns

Streptococci

Bacteria may deposit ____ ________ in the cell, where they serve as an energy reserve.

Sulfur granules

The movement of a bacterium toward or away from a particular stimulus is called

Taxis

Cell wall of gram positive bacteria consist of

Teichoic acids - consist of alcohol and phosphate

Type of motility, A pilus extends by the addition of subunits of pilin, makes contact with a surface or another cell, and then retracts as the pilin subunits are disassembled

Twitching Motility

Spiral Bacteria that look like curved rods

Vibrios

If polar, flagella can be one of the 3....

monotrichous, Amphitrichous, or Lophotrichous

A complex, semirigid structure responsible for the shape of the cell

Cell wall - Most bacteria have one

Bacilli that are oval and look so much like cocci

Coccobacilli

The 3 basic shapes of bacterial cells

Coccus Bacillus Spiral

Protects the cells within it, facilitates communication among them, and enables the cells to survive by attaching to various surfaces in their natural environment.

EPS

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

Endoflagella

- Specialized resting cells - Unique to bacteria, ___________ are highly durable dehydrated cells with thick walls and additional layers. They are formed internal to the bacterial cell membrane. - Formed and found by gram-positive bacteria -survival structure not reproductive - Very resistant

Endospore

80S are

Eukaryotic Ribosomes

A glycocalyx that helps cells in a biofilm attach to their target environment and to each other are called

Extracellular polymeric substances (EPS)

An endospore returns to its vegetative state by a process called...

Germination

Type of motility, The smooth gliding movement of myxobacteria

Gliding motility - Provides a means for microbes to travel in environments with a low water content, such as biofilms and soil

Is a viscous, gelatinous polmer that is external to the cell wall and composed of polysaccharide, polypeptide, or both

Glycocalyx

It is made inside the cell and secreted to the cell surface

Glycocalyx

Material held inside a cell, often consisting of reserve deposits

Inclusions

Is a medium in which the overall concentration of solutes equals that found inside a cell.

Isotonic solution

Are revealed by staining cells with fat-soluble dyes

Lipid Inclusions

The outer membrane of the gram negative cell consist of

Lipopolysacchairdes, lipoproteins, and phospholipids

is a large complex molecule that contains lipids and carbohydrates and consist of three components. 1. Lipid A, 2. core polysaccharide, and 3, an O polysaccharide

Lipopolysaccharide (LPS)

Flagella with a tuft of flagella coming from one pole

Lophotrichous

Destruction causes by rupture of the plasma membrane and the loss of cytoplasm

Lysis

Are inclusions of iron oxide surrounded by invaginations of the plasma membrane. - are formed by several gram-negative bacteria and act like magnets

Magnetosomes

Are large inclusions that take their name from the facts that they sometimes stain red with certain blue dyes such as methylene blue

Metachromatic granules -Known as Volutin -Found in Algae, fungi, and protozoa

The pressure needed to stop the flow of water across the selectively permeable membrane

Osmotic pressure

Substances cross the membrane from an area of high concentration to low, without any energy (ATP).

Passive Process

Includes Simple Diffusion, Facilitated Diffusion, and osmosis

Passive processes

Flagella at one or both poles or ends of the cell is called

Polar

Typically consist of glycogen and starch, their presence can be demonstrated when iodine is applied to the cells. The glycogen granules appear reddish brown and starch appear blue

Polysaccharide granules

Part of the permeability of the outer membrane is due to proteins in the membrane called

Porins - Permit the passage of molecules such as nucleotides, disaccharides, peptides, amino acids, vitamin b 12, and iron

70S are

Prokaryotic ribosomes

Wall-less cell

Protoplast

Function as sites of protein synthesis

Ribosomes

Cocci that divide in three planes and remain attached in cubelike groups of eight

Sarcinae

The most important function of the plasma membrane is to serve as a selective barrier through which materials enter and exit the cell. This function is called

Selective permeability -large molecules can not pass through but small molecules and substances that dissolve easily in lipids can.

is the overall movement of molecules or ions from an area of high concentration to an area of low concentration. The movement continues until the molecules or ions are evenly distributed

Simple Diffusion

Most bacilli appear as single rods called

Single bacilli

Cocci that divide in 2 planes and remain in groups of four

Tetrad

Inclusions that contain the enzyme ribulose 1,5-diphosphate carboxylase

carboxysomes