gene expression Word Scramble
|
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Question | Answer |
Constitutive (house keeping) | –60-80% –Expressed constantly •Glycolysis enzymes |
Controlled genes are : | Expressed only if needed Inducible or Repressible |
Inducible | –lac (lactose) operon |
Repressible | trp(tryptophan) operon |
Inducible operon (lac operon) has an ______________ protein | Active repressor protein |
Inducible | –Induces synthesis of enzymes involved in lactose utilization –Responds to presence of lactose |
Repressible has an _______ protein. | Inactiverepressor protein |
Repressible operon (trp operon) | –Represses tryptophan synthesis –Responds to presence of tryptophan |
Regulatory gene (constitutive) | –Codes for a repressor protein |
Promoter | –Site where RNA polymerase starts transcription |
Operator | –Binding site of active repressor protein –Allows or interferes with the binding of RNA polymerase to promoter |
Structural genes | –Genes under control of the operon |
Lactose operon is influenced | by glucose concentration |
Low cyclic adenosine monophosphate (cAMP)production | High glucose concentration |
Low glucose concentration | High cAMP production |
cAMP binds to a | catabolic activator protein (caP) |
CAP facilitates binding of | RNA polymerase to promoter |
Mutations are: | Permanent” change in the base sequence of DNA |
Variable effect of Mutations: | •Disadvantageous (most often) •Advantageous •Neutral |
Base substitution or point mutation (most common) : | Silent mutation Missense mutation Nonsense mutation |
Different codon, still same amino acid | Silent mutation |
Amino acid substitution, different amino acid | Missense mutation |
Nonsense mutation | Nonsense (stop) codon, early termination of translation |
Frameshift mutation | Insertion or deletion of nucleotide pairs –Long stretch of wrong amino acids |
Chemical mutagens Nitrous acid (HNO2) | Adenine (A) change •Pairs with citosine (C) •Some AT pairs in parent DNA change to CG in granddaughter cells |
Similar to normal nucleosides, but with different base-pairing properties | Nucleoside analogs |
Ionizing radiation | X rays and gamma rays •Generates highly reactive free radicals •Damage of DNA •May break covalent bonds |
Nonionizing radiation | –Ultraviolet (UV) light •Formation of thymine dimers –Interferes with transcription and replication |
Eukaryotes (vertical) | –Formation of reproductive cells |
Mediated by bacterial viruses | Bacteriophages (phages) |
Prokaryotes (vertical and horizontal) | –Transformation –Conjugation –Transduction |
Transformation | Transfer “naked” DNA in solution (from dead cells) among closely related organisms •Natural process only in a few types of bacteria •Major technique in genetic engineering |
Cell processes phage DNA | –Replication –Transcription –Translation |
Phage injects its DNA | into host bacterial cell |
Generalized | •Transfer of any bacterial gene •Lysis of host |
Specialized | •Transfer of an specific gene •Normal reproduction until the lytic cycle is triggered |
Natural selection | –Survival of the fittest |
Diversity | –Mutation –Recombination –Transposition |
–Transposase | •Cutting and resealing DNA •Recognizes recombination sites |
Movable genetic elements | –Carry information for own transposition –Move within DNA molecule –Move to a different DNA molecule –May carry antibiotic resistance genes |
Extrachromosomal genetic material | Self-replicating –1 to 5% the size of bacterial chromosome –Usually not indispensable |
Phage DNA and coat proteins are | are assembled into new phages |
Usually not indispensable |
Created by:
1155187441193384
Popular Biology sets