Lecture 10 Flashcards
(28 cards)
_________ allows
many different proteins to be
produced from the same gene
Alternative splicing, An exon in one mRNA can be an intron in another, and vice
versa
how can we expand the proteome? ( all the proteins in the cell)
alternative splicing!
The different proteins encoded
by the same gene are called
splicing ______ of the protein
isoforms
what are the basic properties of mature mRNA’s?
They each code for a specific
polypeptide.
They are found in the cytoplasm.
They are attached to ribosomes when
translated.
Only the coding region is translated
into a polypeptide.
Most have a non-coding segments: 5’
untranslated region(5’ UTR) and 3’
untranslated region (3’ UTR) .
Eukaryotic mRNAs modifications at
their 5’ (guanosine cap) and a 3’
poly(A) tail
The coding region consists of an ________, which is a continuous stretch of codons that code for the polypeptide primary structure
open reading frame
(ORF)
_______: Converting information from one language to another
language (nucleic acid to protein)
Translation
_______: The set of rules by which the nucleotide sequence of a gene is translated into the amino acid sequence through an intermediary
mRNA molecule
Genetic code
_______: Sequence of three nucleotides in mRNA that corresponds to a
specific amino acid or serves as a start or stop signal
Codon
Codons are not directly recognized by
the amino acids, but rather by adaptor molecules called _____
tRNA (short RNA strand made of 73 to 93 nucleotides)
which form of tRNA can form four short double helix regions with three loops (cloverleaf shape), which then forms a compact, L-shaped structure?
tRNA
Anticodon in the tRNA binds to codon in the mRNA molecule through ______
base-pairing
how many tRNA’s do we have?
50
true/false: There is more than one tRNA for many of the amino acids and some tRNA
molecules can base-pair with more than one codon
true
what is the Wobble Hypothesis?
base-pairing of the third position of a codon isn’t as specific, so that there are less detrimental protein function changes when there is a mistake in the third position
_________ covalently couple each amino acid to the appropriate set of tRNA molecules
Aminoacyl-tRNA synthetases
Each synthetase enzyme recognizes its designated amino acid and
the nucleotides in the _____ loop of the tRNA molecule
anticodon
__________: Complex of ribosomal proteins and ribosomal
RNAs (rRNAs)
Ribosomes
_______ bind to mRNA, capture and position appropriate
tRNA molecules, and catalyze the covalent linkage of amino
acids to form a polypeptide chain, and are composed of large and small subunits
Ribosomes
______ subunit – matches tRNA to mRNA
________ subunit – catalyzes peptide bonds
small
large
Ribosome is a ________: RNAs catalyzes the protein
synthesis (same for spliceosome)
Ribozyme
tRNA-binding sites (the A, P, and E sites) on the ribosome
formed primarily by the _____
rRNAs
what are the three stages of translation?
initiation
elongation
termination
where does translation start?
AUG codon on mRNA
The initiator tRNA carries the amino acid _________
methionine
