Bio Exam 3, Ch. 17
rRNA
part of the ribosome
One DNA strand serves as a ______.
template
___________ is the synthesis of RNA.
Transcription
The anticodon of a particular tRNA molecule is
complementary to the corresponding mRNA codon
In eukaryotic cells, transcription cannot begin until
several transcription factors have bound to the promoter
Initiation
Ribosome binds to mRNA
Missense mutation
change in amino acid
3 nucleotides on RNA= ?
codon
Components of translation:
mRNA, tRNA
Coding regions
exons
RNA polymerase
unwinds the double helix
slide 23
...
Less than ___% of our DNA is translated.
2
Polymerase reads DNA in __ to __' direction.
3,5
DNA contains __ bases, RNA contains __ bases, proteins have __ amino acids.
4,4,20
RNA runs in a ____' to ____' direction.
5,3
Which of the following is NOT true of RNA processing? A. Exons are cut out before mRNA leaves the nucleus B. Nucleotides may be added at both ends of RNA C. Ribozymes may function in RNA splicing D. RNA splicing can be catalyzed by spliceosomes E.A primary transcript is often much longer than the final RNA molecule that leaves the nucleus
A
Which of the following mutations would be MOST likely to have a harmful effect on an organism?
A single nucleotide insertion downstream of, and close to the start of the coding sequence
Messenger RNA
Blueprint for protein that is gonna be made
In transcription, the _______ strand is the template.
Bottom
In DNA, the pyramidines are __ and _. In RNA ^^^^^^ __ and __.
C,T, C, U (in RNA, U pairs with A)
Which of the following is NOT true of a codon? A. It consists of 3 nucleotides B. It may code for the same amino acid as another codon C. It never codes for more than one amino acid D. It extends from one end of a tRNA molecule E. It is the basic unit of the genetic code
D
Which component is NOT directly involved in translation?
DNA
True or False: A protein always starts with Argenine.
False, Methymine
Nonsense mutation
change to a stop codon; leads to a protein that is inactive
3 steps of translation
Initiation, Elongation, Termination
Non-coding regions
Introns
Where does RNA processing happen?
Nucleus
Promoter
Piece of DNA where RNA polymerase binds
When DNA is transcribed, the first piece made is called _______.
Pre-RNA
Elongation
Proper tRNA's align with codons on mRNA, amino acids are added to growing polypeptide
Features of mRNA codons:
Specific, redundant, AUG codes for Met and START
What does the one gene-one enzyme state?
The function of a gene is to dictate the production of a specific enzyme
True or False: Each tRNA binds to a particular amino acid.
True
True or False: Only after mRNA has been spliced and capped and brought to tail, then and only then is it ready to leave the nucleus and be translated.
True
____ leads to sickle cell.
Valine
Substitution mutation
base change
Insertion/deletion
base has been taken out or put back in
Translation occurs in the _________.
cytoplasm
Difference between DNA and RNA
deoxyribose
RNA Splicing
enzymatic removal of introns
mRNA must be _________ the nucleus in order to be translated.
exported out of
Ribosomes are assembled in the ________. And are binding sites for ______ and ______.
nucleolus, mRNA, tRNA
Transcription occurs in the ________.
nucleus
Termination
stop codon reached, polypeptide is released, ribosome releases mRNA
A codon consists of ____ bases and specifies which ____ will be inserted into the polypeptide chain.
three, amino acid
The two main stages of information flow from DNA ---> RNA ---> protein are ____________ and ________.
transcription and translation
