Ch 9, 10,11

Microbiology

Carbon

found from the air, helps create organic compounds

Oxygen

gain from enviornment made through metabolic pathways;O2 makes up 20% of the atmosphere

Hydrogen

splits water, maintain pH, forms hydrogen forms between molecules

Nitrogen

organsim through nitrogen fixation; heteotrophs help create proteinsand nucleic acids(DNA,RNA)

4 organic macromolecule

carbohydrate,lipids, proteins, and nucleic acids

Autotroph

inorganic CO2 as its carbon source

Heterotroph

must obtain C in organic form

a saprobes is and examples of saprobes

Release enzymes to environment and digest food particles. Ex Fungi, bacteria

Active transport

movement against gradient and energy required

Passive transport

no energy is required for the movement of molecules

Osmosis

passive movement of water from area of higher water concentration to an area of lower water concentration

Facilitated diffusion

transport hydrophilic molecules, no energy required, protein carrier

Phagocytosis

destroy large solid particles that invade bacteria and fungi

Pinocytosis

active transport in which cell engulf extracellular fluid with dissolved solutes

Psychrophile

grow in cold, optimum temperature below 15 C,obligate with respect to cold and can’t grow above 20 C

Psychrotrophs

slowly in cold but have temperature above 20

Thermophile

temperature greater than 45 C

Mesophile

grow at intermediate temperature;subtropical and tropical regions

Extremethermophile

grow between 80 C and 120 C

Obligate aerobe

• cannot grow without O2

Aerobic

uses O2

Anaerobic

• without O2

Facultative anaerobe

• capable of growth in the absence of O2

obligate anaerobes

die exposed to O2

Symbiotic-organisms live in close nutritional relationships; required by one or both members

Mutualism:dependent,both members benefit

Commensalism: commensal benefits,not harmed

Parasitism: parasite is dependent and benefits, host harmed

Nonsymbiotic

organisms are free-living, relationships not required for survival

Synergism: members cooperate and share nutrients

Antagonism:are inhibited or destroyed by others

Binary fission

1. Young cell 2. Chromosome is replicated and new/old chromosomes move to different sides of cell 3. Protein band forms the center of cell. 4. Septum formation begins 5. When septum is complete, cells are considered divided.

Generation

required for a complete fission cycle

30 to 60 minutes and can be short as 10 to 12 minutes

bacterial growth curve

Lag phase( cells adjust to a new environment, Exponential Growth Phase(log phase) rapid cell division, Stationary Growth Phase(dividing cells equal the number of dying cells)Death Phase( final stage decline)

DNA

• hereditary information in the form of genes

• Deoxyribose sugar, phosphate, nitrogenous base

• A makes 2 hydrogen bonds to T

• G makes 3 hydrogen bonds to C

• 
  

Eukaryotic DNA

• linear, associated with histone proteins

Prokaryotic DNA

• circular

Helicase

Unzipping the DNA helix

Topoisomerase

Making single-stranded DNA breaks to relieve supercoiling at origin

primase

Synthesizing an RNA primer

DNA polymerase III

(Adding bases to the new DNA chain; proofreading the chain for mistakes)

DNA polymerase I

Removing primer, closing gaps, repairing mismatches

Ligase

DNA during synthesis and repair

Leading strand

The strand of new DNA that is synthesized in a continuous manner in the 5′ to 3′ direction.

Lagging strand

The strand of new DNA that must be synthesized in short segments (in a 5′ to 3′ direction) and later sealed together to form a strand in the 3′ to 5′ direction

Missense mutation

single amino acid

Frameshift mutation

addition or deletion;the mutation is different from what was coded for in the original DNA

 

Transcription

the master code of DNA is first used to synthesize an RNA molecule via a process

mRNA

is a transcript (a copy) of a structural gene or genes in the DNA

tRNA

a copy of a specific region of DNA

rRNA

helps synthesize proteins

Translation

Eukaryote translation

mRNA translated into polypeptide;A site:-peptide bond is formed and translocation occurs, P site:initiator methionine-tRNA initially binds;E site: discharge of tRNA

Prokaryote translation

A site is the entry point incoming charged tRNAs; P site- site holds tRNA molecule linked to polypeptide chain;E site holds tRNA before releasing into cytoplasm

Inducible-operon

operon is turned ON by substrate

Repressible

genes are turned OFF by product synthesized

Genetic Transfer

1.Conjugation-a portion of the chromosome and a portion of fertility plasmid are transferred to the recipient.

2. Transformation- a lysed cell are accepted by a recipient cell;

3. Transduction- serves as a carrier of DNA

Highest resistance

bacterial endospores,prions

Moderate resistance

protozoan cysts, naked viruses; mycobacterium tuberculosis

Least resistance

fungal spores,enveloped viruses,bacterial vegetative cells

Sterilization

destruction of all microbial life, on inanimate objects, performed with autoclave

Disinfection

chemical agent to destroy vegetative pathogens, removes toxins;bacterial endospores are not destroyed

Antisepsis

destroys vegetative microbial life, reducing contamination on a living surface.

Antiseptics

exposed body surfaces to destroy or inhibit vegetative pathogens

Sepsis

growth of microorganisms in blood

Asepsis

: prevents the entry of infectious agents into sterile tissues

Decontamination

actual sterilization isn’t needed to decrease the risk of infection or spoilage

Surfactant

Lose selective permeability; gram-more susceptible

Moist heat

lower temperature and shorter exposure time

Dry heat

moderate to high temperatures(glassware, syringes)

Ionizing radiation

ejects electron, to cause ions to formEx.gamma rays,x-rays

Nonionizing radiation

excites atoms but does not ionize themEx. UV rays

Ionizing radiation

ejects electron, to cause ions to form Ex.gamma rays,x-rays

pyrimidine dimers

mutations;between adjacent bases on the same DNA and interfere with normal DNA replication and transcription.Ex. Ultraviolet radiation