Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
57 Cards in this Set
- Front
- Back
|
DNA |
Double helix consisting of 2 chains of nucleotides. Nucleotides composed of nitrogenous bases, sugar (deoxribose) and phospate Nitrogen bases= Adenine, thymine, cytosine, and guanine A-T, C-G 2 strands are complentary- precise duplication of DNA during cell division. |
|
|
Genetic language consists of 4 bases arranged in sequence that prescribes construction of protein |
Like letters in an alphabet Sequence of 10 nucleotides can have over 1,000,000 possible combinations. |
|
|
Gene |
A segment of DNA that codes for a final product The product can be rRNA, tRNA, but is usually a protein. |
|
|
Bacterial chromosome |
Single loop of DNA Proteins associate with replication and expression are bound to the DNA. Attached at P.M at 1 or more points Tightly packed 10% of cells volume DNA replication and cell division flow of genetic information DNA -- transcriptions -- mRNA -- translation -- protein |
|
|
How many chrosomose base pairs does e. coli have? what size are they? |
4,000,000 base pairs is about 1 mm long |
|
|
Plasmids |
Small loops of DNA, typically despensable Replicates independently from the cells chromosomes. |
|
|
May have genes inducing transfer to another cell Mediated by one kind of plasmid Direct cell to cell contact Must be of opposite mating type Donor carry plasmids recipients don't |
Conjugation |
|
|
Dissimilation |
Code that enzymes that trigger the catobolism of certain unusual sugars and hydrocarbons. Digestion |
|
|
Bacteriocinogenic |
Toxic protein that kill other bacteria. These plasmids have been found in many bacterial genera and they are useful markers for the indentifications of certain bacteria in labs. |
|
|
Resistance |
Plasmids that have significant medical importance. Spread of genes from one organism to another Segments of info, collection of genes that tell cell how to resist antibiotics. |
|
|
Genetic recombination |
Exchange of genes between 2 DNA molecules In bacteria |
|
|
Donor cell |
supplies DNA |
|
|
Recipient cell |
Recieves donor DNA and incorporates it into its own genome (as plasmids or into chromosome) |
|
|
Transformation |
DNA transferred as "naked cell" in solution, then recomined Griffiths experiment in 1928 with Streptococcus pnuemoniae |
|
|
Griffiths Experiment in 1928 with streptococcus pneumoniae |
Virulent smooth (S) strain with capsule Avirulent rough (R) strain without capsule Mix of live R and killed S injected into mice ----> killed Genetic info from dead cells entered live cells and changed them genetically Discovered in 1944 that the transforming agent was DNA In nature death & cell lysis --> Release of DNA Occurs in Bacillus, Hemophilus, Neisseria, Rhizobium, strep and staph (closely related cells) |
|
|
Competent |
Cells are able to take up donor DNA E. coli not naturally competent but can be made competent in 30mm CaCl2 at 0 degrees (mild salt) Permeable to large DNA molecules |
|
|
Conjugation |
Transfer of DNA from donor to recipient involving cell to cell contact and opposite mating types F+ x F- -->F+ with plasmid (F factor) Plasmids replicated during transfer as single strands enter recipient cells. Sometimes F factor becomes integrated into bacterial chromosome by recombination Htr cell (high frequency recombination)
|
|
|
Htr (high frequency recombinant) x F- = F- cell |
Break occurs in integrated F factor Copy of part of F factor leads the way into recipient cell Attached copy of portion of bacterial chromosome follows The longer the cells conjugate the greater the length of chromosome transferred Rarely entire chromosome transferred recombination occurs between the donated HFR chromosome fragments and the recipients chromosomes = recomination F - cells |
|
|
Bacteriophage |
Phage absorbs to donor cell injects its DNA (leaving protein coat outside) Bacterial DNA begins to disintegrate Components of new viruses including viral (DNA) synthesized in bacterium As new viruses are assembled, some may trap bacterial DNA fragments instead of viral DNA Some trap bacteria plasmids |
|
|
Transduction |
(accidently transfer of DNA that produced those viruses) DNA transferred from donor to recipient by bacterial virus (bacteriophage) Bacterial cell lyses to release newly formed bacteriophages unusual phages containing DNA behave as normal phages, absorbing to other bacteria (recipients) and injecting bacterial DNA Donor bacterial DNA recombines with recipients |
|
|
Shigella |
cousin to E. coli - genetic difference In the intestines of cows Meat is almost always contaminated with e. coli Salmonella from large industrial meat farms |
|
|
Which e. coli has strands of shigella? |
E. coli 0157:H7 must of had some conjugation |
|
|
Hemophilus |
absorbs DNA from the atmosphere |
|
|
Hemophilus influenzae |
Does NOT cause influenza, named after a patient who had influenza. Respitory track infection Naturally competent |
|
|
Making a gene product |
E. coli is easily grown and genetically well understood. Endotoxin problems Product must be released by lysis or be linked to naturally secreted substance. Yeast more likely to secrete product animal viruses (vaccinia viruses) engineered to carry genes for antigen or pathogen Vaccine Mammalian cell cultures - hormones ctyokines, interferon |
|
|
Genitically engineered products for medicine |
Insulin, somatotropin produced by e. coli engineered vaccinia virus carries genes for surface proteins of other pathogens. Subunit vaccines produced by engineered cells. |
|
|
Advent of recombinant DNA technology |
Related organisms exchange genes in natural recomination Genes transferred between unrelated species through genetic engineering. |
|
|
Recombinant DNA |
Has been artificially manipulated to recombine. |
|
|
cloning vector |
A DNA molecule used to transmit a gene from one organism to another |
|
|
Recombinant DNA procedures |
Desired gene is inserted into DNA (cloning) vector such as plasmids or viral genome Vector inserts DNA into new cell, which is grown to form a clone large quantites of gene or gene product are harvested from the clone. |
|
|
Restriction enzymes |
recognized and cuts DNA at a particular nucleotide sequence. |
|
|
Sticky ends |
Exposing bare nitrogenous bases at ends of DNA fragments DNA fragments produced by some enzymes will spontaneously link ( with help of DNA ligase) |
|
|
Vectors |
Plasmids viral DNA must be capable of replicating smaller vectors less fragile Maker genes may be used to allow selections of cells antibiotic resistance genes (R factors)
|
|
|
Methods of introducing foreign DNA |
Transformation protoplasts produced by dissolving CWs protoplasts fuse, DNA recombines after removal of CW, electron currents may be used to produce pored through which DNA enters. "DNA gun" used to shoot DNA coated particles of tungsten into plant cells. |
|
|
Microinjection |
micropipette used to inject DNA |
|
|
Sources of DNA |
gene libraries collection of cell clones containing DNA fragments synthetic DNA DNA synthesize chains of 40+ nucleotides. |
|
|
Fungi |
Mycology eucaryotic chemoheterotrophs non-photosynthetic with CW's of chitin, ect. Aerobes or facultative anaerobes Mostly saphrophytic in soil and water about 50 (of 100,000) are human pathogens most important organism in ecosystem. |
|
|
3 Basic forms of fungi |
Molds - multicellular with hyphae (filaments) -forming mycelium -may extend aerial hyphae bearing -reproductive spores (disease in humans) Fleshy fungi- solid mass of hyphae Yeasts- Unicellular, budding (human diseases)
|
|
|
Mycotoxin |
Myc - fungi toxin - toxin |
|
|
Dimorphic fungi |
Generally molds at 25 degrees c and yeasts at 37 degrees c Many are serious pathogens - Histoplasma. Coccidioides |
|
|
Sexual spores |
Resulting from joining of nuclei of opposite mating types |
|
|
Asexual spores |
Produced by cell division (human disease) |
|
|
Arthrospores |
Produced by fragmenting into thickened cells, e.g. Coccidiodes |
|
|
Conidiospores |
Produces in large numbers at end of aerial hypae for air dispersal e.g histoplasma |
|
|
Mycosis Mycoses |
Fungal disease (4 types) |
|
|
Systemic (deep) mycoses |
Spread deeply to internal organs Many due to dimorphic soil, fungi, mostly non-communicable |
|
|
Histoplasma |
(MI RIver) (OH River) Causes histoplasmosis, usually asymptomatic but may affect lungs (mimics TB) other organs |
|
|
Coccidioides |
Coccidioidomycosis San Joaquin, CA 111,000 cases progress to bone, skin, testes, thryroid, (dry conditions) |
|
|
Cryptococcus |
cryptococcosis - not dimorphic encapsuled yeast common in pigeon dung, may infect lung, brain, kidney, bone |
|
|
Subcutaneous mycoses |
Usually enter through puncture, pricks, scratches. |
|
|
Sporothinx Sporotrichosis |
Skin and lymphatic canals affected, rarely other organs. |
|
|
Cutaneous mycoses (dermatomycoses) |
Fungi, feed on keratin, includes: Tinea pedis- athletes foot Tinea crusis - jock itch other ringworm Tinea captitis - ringworm of scalp Tinea corpoins - ringworm of torso Tinea Unguium - Finger nails, toe nails, underneath hard to treat |
|
|
Superficial mycoses |
Caused by fungi that feed on dead cells of skin, hair Tinea nigra - surface, dead cells, dark pigment Tinea versicolor - variations in color |
|
|
Candida Candidiasis |
Opportunist mycoses seen as yeast infections, thrush, rare GI, or systemic infections Often normal flora |
|
|
Mucormycoses |
(common soil) due to mucur, rhizopus, in debilated immuno depressed |
|
|
Pneumocystis pneumonia (PCP) |
Formerly classified with the Apicomplexa was rare before aids, now the leading cause of death in AIDS patients |
|
|
Opportunistic |
Take advantage of someone with poor health P. Carinii |
