PLTW Medical Intervention 1.2 Overview!

This includes all the terms and past quiz we did containing this unit (1.2) goodluck on your test/quizzes! :)

Mutation

A change in the DNA that can sometimes cause a change in the gene product, which is the target of the antimicrobial.

Destruction or Inactivation

Many bacteria possess genes which produce enzymes that chemically degrade the antimicrobial, rendering them ineffective before they reach their target site

Efflux

actively transporting toxic substances—including antibiotics, heavy metals, and metabolic waste—out of cells

Conjugation

Direct cell-to-cell contact through a pilus allows one-way transfer of DNA, typically plasmids, from a donor to a recipient.

Transformation

The ACTION to uptake and expression of foregin DNA (naked DNA) from its environment. Bacterium usually transfer plasmi in order to acquire new genetic traits, such as antibiotic resistance

Transduction

DNA is mistakenly transferred from one bacteruim to another by a virus (bacteriophage, during the infection stage)

Cell competence

The ABILITY of a cell to take up extracellular (naked) DNA from its environment

Naked DNA

purified DNA sequence with no associated proteins

DNA supercoiling

over or underwinding of a DNA strand; an expression of the strain on that strand. This is important in a number of biological processes, such as compacting DNA.

Topoisomerase

an enzyme that maintains the supercoiling of DNA; inhibited by fluoroquinolones

Enzyme Inhibitors

inhibit folic acid synthesis

Peptidoglycan

forms a mesh-like layer outside the plasma membrane of most bacteria, forming the cell wall.

30S Ribosome

tetracyclines use to decode mRNA

Selection Pressure

an agent of differential mortality or fertility that tends to make a population change genetically; any reason for organisms with certain phenotypes to have either a survival benefit or disadvantage.

B-Lactam

Designed to fight bacterial infections by inhibiting the synthesis of the bacterial cell wall, which leads to cell death. 

Tetracyclines

inhibit protein synthesis and alters cell wall; bind to 30S ribosomal unit; effective against certain gram positive and negative bacteria

Fluoroquinolones

inhibits topoisomerases which block DNA replication; inhibit early fracture healing and increase rates of tendinitis; work on some gram positive and gram negative

*prevents the supercoiling of chromosomal DNA?

Sulfonamides

inhibit folic acid synthesis (protein production and cell division) and growth of gram positive and negative bacteria; does not work on human cells

Bacterial Cell Virulence Factors

Plasmid, Capsule, Pili, Endotoxins, Endotoxin LPS layer (in Gram Negative)

Nucleoid

contains bacterial DNA, RNA and proteins

Plasmid

contains code responsible for antibiotic resistance and other characteristics

Ribosomes

performs protein synthesis by reading RNA

Cell Wall

holds bacterial cell together and protects surface

Cell Membrane (also known as the plasma membrane)

holds parts of cell together; responsible for diffusion and transport of materials

Capsule

protects the cell and inhibits phagocytosis by the host cell

Flagella

help cell move

Pili

allow bacteria to attach to other cells

Endotoxins

released into the body when gram negative dies.

• Casues inflammation , headache, or fever to the host upon its (subcoming) death.

What color does Gram + turn when stained

purple

What color does Gram - turn when stained

Red

A chemical removes the cell wall, but leaves the rest of the organism untouched. What does the bacteria lose?

The ability to have a gram stain result

Are bacteria ever naturally resistant?

No

What structure distinguishes prokaryokic and eukaryotic cells?

A nuclear membrane

• (Bacteria dont have a nuclear membrane, instead they have a nueloid and plasmid )

Antibiotic

a medicine (such as penicillin or its derivatives) that inhibits the growth of or destroys microorganisms.

Antibiotic Resistance

Resistance to one or more antibiotics, usually due to additional genetic information

Zone of inhiblitation

The “dead zone” around an antibiotic disk

Penicillins

killing bacteria (bactericidal) through the destruction of their cell walls