A segement of DNA that codes to make a functional product.

Usually a protein.

Adenine------Thymine

Guanine------Cytosine

Deoxyribose is a sugar

DNA is made of Deoxyribose and PO₄ (phosphate) bonds

DNA making an exact copy of itself

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The leading strand is the strand in which the deoxyribose sugars are pointed in the right direction.

the lagging strand is made slowly and in sections becayse deoxyribose is upside down.

1. Transcription

-DNA unzips

-1 strand is used as a template to make mRNA

2. Translation

-mRNA is read by the ribosome in a series of codons

-codon: group of 3 bases which codes for an amino acid

-tRNA attaches to each codon and releases the corresponding amino acid. The amino acids chain together to form a protein.

What is the codon signal for ribosome to start a protein?

AUG (Methionine)

*can also be found in the middle of the protein chain but is always found at the start.

UAA, UAG, UGA

these mean stop and do not code for any amino acid

Frances Krick and Jim Watson

Feb. 28 1953

• invented by professor Ames to determine if something causes cancer

• He mutated salmonella, which normally grows well anywhere, and mutated it to require a specific nutrient.
• He then put it on a media that lacked that nutrient.
• To determine if something caused cancer he would put that substrate on the inoculated media and if it caused salmonella to mutate back to its original form and grow on the specialized media then it can possibly cause cancer.

Transformation

Transduction

Conjugation

Plasmid

Transformation:

A "competent bacteria" picks up "naked" DNA

**competent: has the ability

**naked: just lying around

When a bacteriophage accidentaly carries host DNA to new host.

*bacteriophage: a virus that infects and replicates within bacteria

1. Lag Phase: Orgs are increasing in size but are inactive
2. Log phase: Logarithmic growth->orgs grow dramatically
3. Stationary phase: some are dividing and some are dying but overall numbers stay the same.
4. Death phase: Lots of waste products. No more nutrients. Organisms dying.

What is 

α (alpha), β (beta), and γ (gamma) hemolysis?

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α hemolysis: Hemoglobin is turned into methemoglobin by hydrogen peroxide produced by the bacteria

β hemolysis: Is complete lysis of red blood cells

γ hemolysis: does nothing to red blood cells

• G+, cocci clusters
• normal skin flora

**"Staphylo" means bunch of grapes

• Causes 20 diseases:
• pimple/ boil
• bedsores
• septicemia
• sinusitus, conjunctiva, bronchitus, osteomiolitus, ear infection, etc.
• toxic shock syndrome
• endocarditis
• food poisoning
• wound infection
• endocarditis-inflammation of heart valves

• Virulence factors
• Resists phagocytosis
• Lipases and proteinases allow staphylococcus to invade
• hyaluronidase: hyaluronic acid is the glue that holds cells together.
• Leukocedin: destroys neutrophils and platelets
• α, β, γ, δ toxins all cause β hemolysis
• enterotoxins A, B, C, D...
• entero refers to gut: these all cause food poisoning
• Exfoliation toxin: causes a rash
• Coagulase: causes plasma to clot
• DNAse: breaks down DNA

**not every strain of S. aureus causes every virulence factor** 

• γ hemolytic
• has no virulence
• coagulase -
• white colonies
• cocci clusters

• γ hemolytic
• coagulase -
• yellow colony
• cocci tetrad arrangement
• no virulence
• found on skin

• G+, cocci chains or pairs
• normal oral, gut and vaginal flora
• Lancefield studied β hemolytic strep and grouped them into A, B, C, D... according to COHs in cell walls
• Griffiths divided β hemolytic strep. Group A by M proteins in cell wall. 1, 2, 3......60.
• All Catalase -

Streptococcus pyogenes

"pyogenes" means fever causing

• G+, cocci pairs
• Causes:
• strep throat
• pneumonia
• meningitis
• rheumatic fever-sclerosis of heart valves
• glomerulo nephritis
• flesh eating disease
• scarlet fever
• tonsilitis
• Virulence factors:
• erythrogenic toxin->causes red rash
• streptolysin S & O-> bursts RBCs
• DPNase-> denatures DPN and kills neutrophils
• Streptokinase->dissolves blood clots
• hyaluronidase->breaks down hyaluron which holds  cells together
• DNAse-> breaks down DNA
• Amylase-> breaks down starch 
• has a capsule-> protects against phagocytosis

Group B beta hemolytic Streptococcus because it is very dangerous for babies in vaginal birth. 

If present, women must take antibiotics or be given a C-Section.

• formerly called Gr. D β Strep.
• G+, diplococci
• Can be β, α, γ hemolytic depending on its conditions
• resistant to antibiotics
• can cause urinary tract infections
• can cause wound infections
• catalase -

• G+, diplococci
• α hemolytic
• can cause:
• ear infection
• conjuctivitis
• tonsilitis
• ear infection
• pneumonia
• meningitis
• Normal throat Flora--> creates a capsule when it spreads to other areas than your throat. 

• Gram + Rod, chains or single
• found in dirt
• makes an endospore

• G+ rod
• grows on grains
• metabolizes starch
• causes food poisoning

• G+ rod
• causes anthrax

• G+, Rod
• long slender rod chains
• found in dairy, dirt, water, and sewage.
• normal oral, gut, and vaginal flora.
• α hemolytic
• Catalase -
• lactose + ---> lactic acid
• Makes yogurt, saurkraut, pickles, kimchi, and cheese

Corynebacterium

• tiny G+ rods, single arrangement
• grows best aerobically
• Corynebacterium diphtheriae
• causes diphtheria
• forms grey curtain across the inside of throat
• fatal to infants- obstructs airway

• tiny G+ rods, single arrangement
• P. acnes - causes acne

• anaerobic
• found in dirt
• G+ rod, terminal endospore
• doubles in # every 12 minutes
• Makes a lot of gas
• There are 150 diff species

• G+ rod
• causes botulism, food poisoning, and paralzes the muscles, esp. diaphragm
• does not grow in acid pH
• used to make botox injections
• some legitimate medical uses for botox are to stop excess salivation or persperation
• secretes the most toxic substance found in nature.

• causes tetanus
• prevents muscles from relaxing
• DPT shot
• Diphtheria, Pertussis, Tetanus
• Rusty nails are likely to contain C. tetani because as the metal is oxidized it creates a pocket of deoxegenated air which is perfect for the anaerobic bacteria

• gas gangrene
• produces a lot of gas and kills tissues

• referred to as C.dif. in hospitals
• very difficult to kill with antibiotics
• antibiotics kill normal gut flora and without competition C. dif overgrows very easily.
• causes diarrhea

• very slow growing like a fungus
• 33 hours to double in #
• waxy coat on cell wall makes it difficult for nutrients to go in as well as antibiotics->difficult to kill
• strict aerobe

• transmitted via respiratory tract
• 2 stages of tuberculosis
• 1.) no symptoms, non-contagious, although M. tuberculosis may be present.
• 2.) symptoms, contagious.
• Tests for exposure:
• PPD->skin test "Purified Protein Derivative"
• Gold test- quick, easy, accurate test

Mycobacterium avium-intracellular

if someone gets tuberculosis from this they are tested for AIDS immediately because it only happens when immune system is severely suppressed.

-Must take antibiotics for 6 months, no less.

• G- diplococci
• Common oral flora- many species
• Oxidase +
• only 2 species are disease causing

• fastidious
• temp. 35°C-37°C
• 10% CO₂
• require "chocolate" agar or "Thayer martin" media
• difference between N. gonorrhoeae & N. meningitidis
• gonorrhea: Glucose +, other sugars -
• meningitidis: Glucose+, Maltose +, other sugars -

• Chocolate agar: blood added to agar when agar is hot along with extra nutrients
• Thayer-Martin agar: Choc. agar w/ antibiotics to make agar selective and enriched.

Genus that is

G+, cocci, catalase +, clusters

Genus that is 

G+, cocci, catalase+, tetrad

Genus that is

G+, cocci, catalase+, cocci chains or pairs

Genus that is

G+, cocci, catalase -, diplococci

Genus that is

G+, rod, catalase +, no endospore, prefers air

Genus that is

G+, rod, catalase +, no endospore, prefers no air

Genus that is 

G+, rod, catalase +, endospore +, waxy coat

Genus that is

G+, rod, catalase+, endospore+, no waxy coat

Genus that is

G+, rod, catalase-, rapid growth

Genus that is

G+, rod, catalase-, slow growth

Genus that is

G-, rod, facultative respiration

Genus that is

G-, rod, aerobic, Oxidize glucose+

Genus that is

G-, rod, aerobic, glucose oxidize -

Genus that is

G-, cocci

exoenzyme gelatinase hydrolyzes gelatin

positive test when gelatin stays liquid below 20°C

exoenzyme urease hydrolyzes urea

positive test when the pH rises and turns phenol red to pink

Deamination is the removal of the amino group from a protein. This produces an organic acid.

Ferric ion reagent should produce green color on a positive test

desulferase enzymes remove hydrogen sulfide from sulfur containing amino acids.

Peptone iron deep will turn black in the stab mark if bacteria has desulferase

M=motility

I=Indole Kovac's reagent turns red to indicate that the amino acid tryptophan was converted to indole

O= Ornithine Decarboxylation creates alkaline pH and is indicated by bromcresol purple turning purple. 

In anaerobic respiration, some organisms reduce nitrates to nitrites  or to nitrogen gas.

Gas in durham tube=nitrogen gas production

turning red after nitrate reagent A&B=nitrite production

Neither=no anaerobic respiration

aerobic bacteria have cytochrome c

Oxidase reagant will turn bacteria purple if cytochrome c is present

Catalase breaks hydrogen peroxide into water and oxygen.

Positive catalase test when hydrogen peroxide bubbles on bacteria.