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genetics
last slides of genetics
33
Microbiology
Undergraduate 2
04/06/2011

Additional Microbiology Flashcards

 


 

Cards

Term

Protein Folding

  Molecular Chaperones

 

Definition

Have protein, it is in primary structure
Some proteins are incapable of folding correctly
To fold correctly, they need molecular chaperones
Things that help the proteins that are unbale to fold properly, help them to
2 ways:
Need atp
One is Groel- threaded throiugh components to become active
GroES
DnaK
DnaJ
Need energy

  

 

Term

Protein Secretion

  Signal Sequence

 

Definition

 

  •      15to 20 amino acids.
  •      Located at beginning of protein.
  •      Signals cell’s secretory system that protein needs to be exported.
  •      Also prevents complete folding which will inhibit secretion.
  •      Necessary for proteins coming in and out of the cell

 

 

Term
SRP
Definition

  •      small protein and 4.5S RNA.
  •      Recognizes signal sequence-containing protein and directs it to special membrane protein complex for secretion.
  •      In common diseases, where if protein doesn’t have these, protein wont be secreted or where supposed to go. Leads to diseases- ice hill

Term

Protein secretion

Definition
Transported proteins are then threaded through the membrane in an unfolded state.
Term
Post-translational modification
Definition
removal of signal sequence, during transport, by a protease.
Term

Secretion of Folded Proteins

  TAT System

Definition

  •      Some transported protein contain small cofactors.
  •       Added to protein as it is folded into its final form.
  •      These proteins are transported by the Twin Arginine Translocase protein export system.
  •       Signal sequence has a pair of arginines.
  •       These arginines are recognized by the TatBC proteins.

Term

Secretion of Folded Proteins

  TAT System

Definition

  •      TatBC proteins carry the protein (to be transported) to the TatA (membrane transporter).
  •      Energy for transport provided by proton motive force.
  •      Thus, proteins that function in energy metabolism are required in the periplasm.

Term

Mutation

Definition

  •      Inherited change in the nucleotide sequence of genome.
  •       Beneficial, neutral, or detrimental.

Term

           Mutation

  Genotype

Definition
nucleotide sequence of a trait.
Term

Mutation

Phenotype

Definition
physical expression of the trait.
Term

Mutation

Wild-type

Definition
is a strain isolated from nature.
Term

Mutation

Mutant

Definition
is a strain carrying a change in nucleotide sequence.
Term

Genotype

Definition

  •     hisC gene-encodes histidine synthesis
  •     (three lowercase followed by capital letter all in italics) 

Term

Mutation

  Phenotype

Definition

  •      His+ or His- (capital letter followed by two lowercase letters with a + or -)
  •      His+ strain capable of making histidine.
  •       His- strain incapable of making histidine.

  

Term

Mutations

 

Definition

Change in nucleotide sequence
Can occur spontaneously
Are rare events approx. 10 to the minuse 9
Are concern is anything that will increase mutation rate
munigen- anything that will increase muation rate
2 types= physical- xrys, ultraviolet light, gama rays, beta particles, radiation
Chemical-

  

 

Term

Types of Mutations

Point mutations (bp substitution)

Definition
single base pair substitution
Term

Types of Mutations

PKU

Definition

  • individual has a one base pair change in gene for metabolims of phenylalanine
  • Normal – when degrade phenylalanineà phenylpyruvic acid
    With PKU lack enzyme to break down properly
    Convert phenylalanineà

Term

Types of point mutations

  missence point mutation

Definition
at instead of TA- faulty protein
Term

Types of Mutations

Nonsence mutation

Definition
GC instead of CG- incomplete protein
Term

Types of Mutations

Silent mutation

Definition
TA instead of CG- normal protein but is silent mutation= no effects. 
Term

Types of Mutations

Frameshift mutations

Definition

mutation, can have an insertion of an extra base pair or multiple base pairs or you can have deletion of single base pair or multiple base pair

  • Reason called this is because, codons are shifted, frame is different. a no stop codon.
    Mostly detremental

 

Term

Types of Mutations

  Frameshift mutations

Inversions

Definition
piece chromosome taken out and then put back in after inverted
Term

Types of Mutations

  Transposons

 

Definition

 

  •      insertion of a transposable element.  If occurs within a gene, loss of gene function ocurrs. Jumping genes

 

Able to cut themselves out of locas/location on the chromosome and move on another part of chromosome and insert themselve
Can reinsert themselves on a different chromosome
Loss gene function sometimes
Rare and not found in every organism, movement is uncommon
Barbra mcklintock discovered transposons in corn.

 

Term
Translocations
Definition

- in DNA its translocated somehwere else. Important if gene is supposed to be In certain place, what regulatest he gene will be lost.

Cell making to much product
  

Term

Mutagenesis

  Mutagens

Definition

  •      agents that cause mutations.

  Physical agents

  •       Radiation-Ionizing and non-ionizing   radiation.

  Chemical agents

  •       Nucleotide base analogs
  •       Alkylating agents
  •       Intercalating agents.

Term

Mutagenesis

  Physical

  Non-ionizing radiation-UV light sterilization

Definition

  •       Useful for isolation of mutants
  •       Allows use to induce mutations and isolate mutants
  •       260 nm-wavelength of maximum absorption
  •        Formation of pyrimidine dimers-the covalent bonding together of adjacent pyrimidines (C or T).
  •        Causes a misread by DNA polymerase during replication

Term

Mutagenesis

  Physical

  Ionizing radiation-gamma, cosmic and X-rays.

Definition

  •       Cause ionization of water and other substances which causes mutations.
  •       Free radicals react with and inactivate macromolecules such as DNA.à mutation or inactivation of DNA
  •       Superoxide, hydrogen peroxide

  Repair mechanism

  •       Light repair and dark repair mechanisms

Term

Mutagenesis

  Physical

DNA repair mechanisms

Definition

  •      enzyme systems that recognize damage to DNA, excise (cut out) the damaged base pairs, synthesize replacements, and insert correct bp sequence into DNA.
  •      If damage to extensive, may not be bable to repair it

Term

Mutagenesis

  Physical

Ames Test (Bruce Ames-Berkeley)

Definition

  •      Determine mutagenesis and carcinogenesis of chemicals.
  •      Many chemicals don’t know what the mutagenesis is or carcinogenesis
  •       Cost a lot of money to stream chemicals and determine whether they are these. 

Term

Mutagenesis

  Ames Test

Definition

  •      Salmonella species that is His-.- lacked ability to make own histdadine amino acid

Need to put histadine in the media

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