Chapter 17 Flashcards
The process by which DNA directs protein synthesis, includes two stages.
Gene expression
What are the two stages of gene expression?
Transcription and Translation
Who suggested that genes dictate phenotypes through enzymes that catalyze specific chemical reactions?
Archibald Garrod
Who speculated that the eye color of fruit flies are due to a mutation of an enzyme?
George Beadle and Boris Ephrussi
Carries the information that is encoded from the DNA
Messenger RNA
Folded RNA with one specific amino acid bonded into it
Transfer RNA
Together with a protein complex, these RNAs are pert of the ribosomes whose function is to synthesize proteins.
Ribosomial RNA
The process of converting the DNA to mRNA
Transcription
converting the RNA into a protein sequence
Translation
A series of non overlapping, three nucleotide combinations.
Triplet code or codon
RNA is synthesized using _______, which pries the DNA strands apart and joins together the RNA nucleotides
RNA polymerase
What are 3 steps in transcription?
Initiation, Elongation & Termination
What stage in transcription does the nucleotide sequence in the DNA where the RNA polymerase and transcription factors binds.
Initiation
What stage in transcription where the RNA polymerase does not need a primer to start this process?
Elongation
What are the 2 distinct DNA strands?
Coding & Template
This is also called as the sense strand; The strand that has a similar sequence to the mRNA.
Coding Strand
This is also called as the antisense strand; The DNA strand that acts as a basis for the mRNA, therefore, complementing it.
Template Strand
This prevents the mRNA from certain kinds of degradation.
5’ cap
This helps against degradation in the cytosol and helps the ribosomes recognize the mRNA
Polyadenylation
What is the eukaryotic pre-mRNA non coding region?
Introns
What is the eukaryotic pre-mRNA coding region?
Exons
Catalytic RNA molecules that function as enzymes and can splice RNA
Ribozymes
What helps a cell translate an mRNA message into protein?
Transfer RNA and Ribosomes
A tRNA with a bonded amino acid
Aminoacyl-tRNA
Facilitate specific coupling of tRNA anticodons with mRNA codons in protein synthesis
Ribosomes
3 binding sites for tRNA
A (aminoacyl) site, P (peptidyl) site, E (exit) site
Changes in the generic information, in our case the DNA, either due to mistakes in replication or as a result of environmental factors.
Mutations
Changes in just one nucleotide pair of gene
Point mutations
Replaces one nucleotide and its partner with another pair of nucleotides
Single nucleotide-pair substitutions
Additions or losses of nucleotide pairs in a gene
Nucleotide insertions or deletions
Type of mutation that have no effect on the amino acid produced by a codon because of redundancy in the genetic code
Silent Mutation
Type of mutation that is a still code for an amino acid, but not the correct amino acid
Missense mutation
Type of mutation that change an amino acid codon into a stop codon; most lead to nonfunctional protein.
Nonsense mutation
Steps in Elongation (Translation)
Codon Recognition - Peptide bond formation - Translocation
