mmbio ch 4

Ribosomes of prokaryotes

30s+50s= 70 s 1 rRNA + 2 rRNA smaller and less dense compared to eukaryotes several antibiotics inhibit protein synthesis in prokaryotes some attach to the 30s unit and others to the 50s unit but none att

Speroplasts

A speroplast is a Gram Negative bacteria with cell wall damage (or none at all) that will burst in a hypotonic environment

Atrichous are

Bacteria that lack flagella

Gram positive versus Gram Negative VS Mycobacteria

Both groups contain unique molecules. Gram-negative cell walls have lipopolysaccharide (LPS) and an outer membrane. gram positive cell walls have teichoic acids.

Antibiotics often attach the ____ _____

Chemicals that damage bacterial cell walls often do not harm the cells of an animal host because the bacterial cell wall is made of chemicals unlike those of eukaryotic cells. This makes the cell wall an excellent target for some antimicrobial drugs

Protoplasts

Gram + bacteria with cell wall damage (or none at all) that will burst in a hypotonic environment

Gram Positive Cell Walls have:

Gram-positive cell walls consist of many layers of peptidoglycan. In addition, they often contain teichoic acids which, among other things, provide much of the wall's antigenic specificity and thus make it possible to identify bacteria by certain lab tests.1

Capsule vs slime layer on a prokaryote

If the glycocalyx is firmly attached to the cell wall, it is called a capsule. If it is loosely attached to the wall, it is called a slime layer.

inclusions (bacteria's garage)

Inclusions are also known as granules and specific ones can store carbohydrates, lipids, sulfur, and even magnetic iron oxide.

Lipoteichoic acid links to _________.

Lipoteichoic acid links to plasma membrane

Fimbrae & Pili

Many gram-negative bacteria contain hair-like appendages that are shorter, straighter, and thinner than flagella.

Mycobacteria

Mycobacteria have atypical walls and mycoplasma have no cell walls at all. Identified by the acid-fast stain.

Penicillin was called a "miracle drug" because it doesn't harm human cells. Why doesn't it?

Penicillin inhibits peptide bridges in peptidoglycan

Pili transfer ____. This is know as _______.

Pili, the second kind of structure, are involved in the transfer of DNA from one cell to another. The transfer of genetic material through pili is called conjugation.

Plasmids

Plasmids are small circular extrachromosomal genetic elements that replicate independently of the chromosomal DNA. Although the genes in the plasmids are generally not crucial for the survival of the bacterium under normal conditions, these genes may confer an advantage under certain conditions, by making the bacterium antibiotic resistant or tolerant to metals, for example.

Counter Clockwise rotation of flagella produces what type of motion? And clockwise results in?

Rotate flagella to run in a straight line (counterclockwise) or tumble (clockwise) both have 2 syllables

Axial Filaments

Spirochetes move by means of axial filaments, which are bundles of fibrils that arise at the ends of the cell under an outer sheath and spiral around the cell. These cause the spirochete to move in a corkscrew manner.

Teichoic acid links to

Teichoic acid links to peptidoglycan

nucleoid

The area where the bacterial chromosome is found is called the nucleoid.

What are bacterials cell walls made of?

The bacterial cell wall is made of a macromolecular network called peptidoglycan.

The enzyme Lysozyme is found where? And damages the the cell walls of what kind of bacteria?

The enzyme lysozyme found in tears, mucus, and saliva damages the cells walls of many gram-positive bacteria & gram negatice bacteria making them vulnerable to lysis.

Major Function of Cell Walls (almost all prokayotes have cells walls)

The major function of the cell wall is to protect the cell from rupturing when the water pressure inside the cell is greater than that outside the cell. The cell wall contributes to the ability of some bacteria to cause disease and is the site of action of some antibiotics, such as penicillin.

Plasma Membrane of bacteria--characteristics

The plasma membrane encloses the cytoplasm. It is selectively permeable. Phospholipid bilayer Peripheral and integral proteins No organelles, so many of the enzymes responsible for metabolic processes are stored in the plasma membrane. Fluid mosiac model -- things are not fixed by move freely.

Items found in the cytoplasm of bacteria

Water Inorganic molecules organic molecules DNA or RNA Ribosomes inclusions

prefixes for : pairs chains grape like clusters

When cells are arranged in pairs, the prefix diplo- is used, as in diplococci. When cells are arranged in chains, the prefix strepto- is used, as in streptococci or streptobacilli. Those cocci that form grape-like clusters are called staphylococci. These group characteristics often help us identify certain cocci.

describe bacterial DNA

circular

peritrichous

flagella all over the cell

Gram Negative Cell Walls Have

gram-negative cell walls contain only a thin layer of peptidoglycan as well as an outer membrane. The outer membrane has a strong negative charge that protects the cell from phagocytosis, and acts as a barrier to certain antibiotics, lysozyme, detergents, and other chemicals. The gram-negative cell wall also contains LPS, or lipopolysaccharide. When the cell disintegrates in the host's bloodstream, the lipid portion of the LPS, called lipid A, is released as an endotoxin that can cause illness. The outer membrane of the gram-negative cell consists of lipopolysaccharides (LPS), lipoproteins, and phospholipids (see Figure 4.13c). The outer membrane also provides a barrier to certain antibiotics (for example, penicillin), digestive enzymes such as lysozyme, detergents, heavy metals, bile salts, and certain dyes.

atrichous

lack flagella

Describe the cell wall of mycobateria

members of the genus Mycoplasma, lack cell walls completely and some, such as Mycobacteria, have atypical walls that contain high concentrations of mycolic acid. This prevents them from reacting in the gram staining procedure. They do stain positively with another staining procedure, called the acid-fast stain.

lopotricous & monotrichous & amphitrichous

polar at one end or both mono=one end lopotricous multiple at one end amphitrichous= at both ends

Ribosomes are the site of

protein synthesis in bacteria. Bacterial ribosomes are slightly different than eukaryotic ribosomes. * great target for medicines

characteristics of glycocolyx

sticky viscous polymer\ found on prokayotes & Epithelial cells of animals

Define Taxis phototaxis chemotaxis

taxis is when bacteria to move towards or away from a stimulus through flagella chemical response light response

Name the key component of the cell wall of 1. Protozoa (Eukaryotic) 2. Algae (Eukaryotic) 3. Fungi (eukaryotic)

1. Protozoa is pellicle, protein 2. algae cell wall is cellulose 3. fungi cell wall has chitin

List characteristics of prokaryotic cell wall external structures

1. many cells have a glycocalyx external to their cell wall. 2. Some prokaryotic cells have flagella for movement 3. Axial filaments 4. Pili Fimbrae

The purpose of the capsule

1. to protect pathogenic bacteria from phagocytosis by host cells 2. Aid in attachment to surfaces inside and outside our bodies.