Protein synthesis 24
The transcription is:
synthesis of RNA on DNA template
synthesis of a protein on ribosome
replication of DNA
release of water vapor from the leaves of a plant
The translation is:
synthesis of RNA on DNA template
synthesis of a protein on ribosome
replication of DNA
release of water vapor from the leaves of a plant
Transcription and translation of a gene composed of 30 nucleotides would form a
protein containing no more than ___ amino acids.
10
15
60
90
During translation the ___ site within the ribosome hold the growing amino acid
chain while the ___site holds the next amino acid to be added to the chain.
A,P
P,A
A,B
B,A
Which of the following is an example of the degeneracy of the genetic code?
each amino acid is encoded by more than one codon (with few exceptions)
each codon specifies more than one amino acid
the first two bases specify the amino acid
all of the above
A DNA strand with the sequence 3’AACGTAACG5’ is transcribed. What is the
sequence of the mRNA molecule synthesized?
5’AACGTAACG3’
5’UUGCAUUGC3’
5’AACGUAACG3’
5’TTGCATTGC3’
Of the ___ different possible codons, ___ usually specify amino acids and ___ signal
stop.
20, 17, 3
180, 20, 60
64, 61, 3
61, 60, 1.
Which of the following statements is true?
introns are the parts of mRNA that are translated
introns are the part of DNA that are not trancribed
introns are the parts of a gene that are transcribed but not translated
prokaryotes have more introns than eukaryotes
Which of the statements below is false?
The genetic code is overlapping
The genetic code is universal
Degenerate codons specify the same amino acids.
The genetic code is triplet.
DNA and RNA polymerases move along their templates in the ____direction. A new
DNA chain or RNA transcript is always synthesized in the ___ direction.
5’ to 3’; 5’ to 3’
5’ to 3’; 3’ to 5’
3’ to 5’; 5’ to 3’
3’ to 5’; 3’ to 5’
The first mRNA codon to specify an amino acid is always
TAC
UAA
UAG
AUG
Amino acids are carried to the site of protein synthesis by:
transposons
carrier proteins
ribosomal RNA
transfer RNA
Synthesis of protein is called:
translation
transcription
replication
transpiration
When we say the genetic code is degenerate, we are referring to the fact that:
Some extra protein is always formed, even when it isn't needed
Placement of some amino acids is specified by more than one codon
Several amino acids can be specified for by the same codon
Three codons do not specify any amino acid
What source of energy does aminoacyl-tRNA synthetase need to attach an amino acid
to its tRNA?
cAMP
ADP
ATP
UTP
The triplet group of bases of mRNA which says, "Put this amino acid here" is called
a/an:
codon
anticodon
operator
promoter
When protein synthesis is going in a cell, the mRNA moves rapidly through a group
of protein synthesizing structures called, collectively
polyribosomes
Golgi apparatus
endoplasmic reticulum
nuclear pores
Which codons function as terminator codons?
ATP and AAA
UAG and UAC
UAA and UAG
AUG and AAU
If you recall, synthesis of both DNA and RNA started at the 5' end of the growing
chain, or the 3' end of the template. Synthesis of protein, however, starts at the 5' end
of the template. How could this help the organism?
This protects the growing polypeptide chain
This happens only in prokaryotes; in an organism as complicated as eukaryotes,
protein synthesis can start at either end
This makes it possible for transcription to begin while replication is still occurring
Translation can begin while transcription is occurring. This gives the organism a
quick start at protein synthesis
If you had taken a biochemistry course in the 1960s, you might have learned that 61
of the possible codons actually coded for placement of amino acids, and that there
were three "nonsense" codons which didn't seem to direct placement of any amino
acid. Now, of course, we know that all the codons are useful. What do those three
nonsense codons actually do?
These three are stop codons
These are extra codons which may be used in case of mutations
These three codons specify isomers of the branched chain amino acids
These three codons direct placement of glutamine and asparagine
The base thymine is always paired with ___.
Adenine
Guanine
Cytosine
Uracyl
The sequence of one strand of DNA is 5’ TCGATC 3’. The sequence of the
complementary strand would be.
3’ AGCTAG 5’
5’ TCGATC 3’
5’ GCTAGC 3’
5’ GATCGA 3’
Genotype is to DNA as phenotype is to
Genotype
Proteins
Expressivity
RNA