D1.2 Protein Synthesis Flashcards
The _____ will have the same sequence as the ____ strand of the ____ but all Ts will be replaced with Us.
mRNA, coding, DNA
RNA polymerase connects _____ RNA bases to the DNA during _________.
complementary, transcription
tRNA brings a amino acid (_____) and reads nucleotides in “series of three” known as a ____.
anticodon, codon
The anticodon for AUG is ____ . It codes for ____.
UAC, methionine
the tRNA leaves but the amino acid forms a _____ bond with the 2nd amino acid.
peptide bond
List complementary base pairs:
A-T and C-G
(The base U pairs with A in RNA.)
___ bonds are found between the bases of the DNA strands.
Hydrogen
What would be the mRNA stand if the DNA strand was : TAGCGA
AUC-GCU (The mRNA will have the same sequence as the coding strand of the DNA but all Ts will be replaced with Us.
The mRNA will have the same sequence as the coding strand of the DNA but all ___ will be replaced with ___.
Thymine, uracil
In eukaryotes, Transcription is an essential step in ______ _______.
gene expression
Transcription:
synthesising(making) RNA using DNA as a template
What’s the function of ribosomes during translation.
catalyse the formation of peptide bonds
tRNA __________ during translation.
attaches to and delivers amino acids to the ribosomes
The mRNA binds to ________ of the ribosome during translation.
the small subunit
Identify which option refers to ‘degeneracy’ in the genetic code.
The existence of multiple codons that can code for the same amino acid.
Universality of the the genetic code: is the ____ for all organisms. The codons code for the ___ amino acids regardless of the type of organism.
same
To find the amino acid that the tRNA anticodon brings, you can use a _______.
codon chart (reads mRNA sequence)
Elongation in translation involves the formation of _____ bonds between ____.
peptide, amino acid
Point mutations.
insertions, deletions, and substitutions of a single nucleotide
Which mutation occurs in sickle cell anaemia.
substitution mutation
In transcription, the RNA polymerase must bind to the _____ region before it can begin transcribing the gene beginning at the start codon.
promoter
directionality of transcription refer to
The direction of RNA polymerase movement along the DNA template strand.
Due to how it bonds to the ribosome, the mRNA is always read in the _____ direction in ______.
5′ to 3′, translation
Describe the role of non-coding sequences in DNA.
They regulate gene expression and provide functional diversity.
The alternative splicing process allows for production of multiple _____ from a single gene.
proteins
Which refers to post-transcriptional modification of mRNA in eukaryotes.
The processing and modification of pre-mRNA into mature mRNA.
Name the post-transcriptional modification of mRNA in eukaryotes.
I. addition of a 5′ cap
II. addition of a poly-A tail
III. remove introns
Identify how alternative splicing produces variants of a protein.
By modifying the sequence of exons included in the mature mRNA. (variety of polypeptides from the same gene.)
What’s true about variants of a protein generated through alternative splicing.
They have different functions or properties.
initiation (translation)
The ribosome binds to mRNA molecule.
What’s involved in modification of polypeptides to their functional state.
The folding, cleavage and/or chemical modification of the polypeptide.
Role of proteasomes.
Breaking down and recycling unwanted or damaged proteins. (provides a source of amino acids to the cell)
Role of pre-proinsulin in insulin production.
Pre-proinsulin is an inactive precursor that undergoes post-translational modification to become insulin. (Pre-proinsulin is the translational product of the insulin gene. It is then modified post-translation to become insulin.)
The significance of proper protein folding for biological function demonstrates ___________.
the modification of polypeptides to their functional state using pre-proinsulin.
transcription-Sense Strand
The DNA sense strand has the same sequence as the mRNA, except that thymine (T) in DNA is replaced by uracil (U) in RNA. (The sense strand is the DNA strand that IS NOT read by the mRNA)
Translation-Antisense Strand
the strand that is actually used for transcription (mRNA does base pairing with)
DNA is most stable when _____. When strand is temporarily separated ________ can occur.
strands are together, mutations
All cells in the body contain the full _____, however not all genes are ______.
genome (genetic code), expressed
There is a _____ codon and _____ codon on each mRNA strand
start, stop
tRNA stands for ______.
transfer RNA
Ribosome has ___ subunits. The small subunit _____. The large subunit _________.
2, binds to mRNA, has tRNA binding sites & catalytic sites to create peptide bonds
Possible combinations of the bases
64 amino acid combinations
A,P,E site on the large subunit of the ribosome during translation
A - initial binding site for tRNA, peptide bond formed
P - “Empty” tRNA moves here as a new tRNA binds to the mRNA in the A site.
E - Exit site
The movement through the A, P, and E sites result in ______.
elongation of the polypeptide chain
Mutations are ____. Base substitutions can ________.
changes in bases sequence(s) of a gene
- change one amino acid or overage protein structure
______ mutations results in sickle cell anemia
hemoglobin
Both transcription and translation happen in the __________ end.
5’ to 3’
Section of DNA that serves as a binding site for RNA polymerase or other proteins that control transcription: beginning of a gene.
Promoter
Molecules that regulate gene expression by promoting or inhibiting transcription
Transcription factors
non-coding region.
not coded for polypeptides ( they are not a gene)
list examples of non-coding regions:
-base sequences that produce tRNA or rRNA
-Promoters
-Telomeres (structural DNA at the end of chromosomes)
-Introns (edited out after transcription)
Post transcriptional modification happens only is _____ cells. This is because they have a _____ which is separated from cytoplasm.
It allows to _________.
eukaryotic, nucleus, make different versions of a protein with same gene
Mature mRNA is _____________.
the final design of mRNA before it leaves the nucleus. (removal of introns, addition of 5’cap, poly- A tail)
Alternative splicing
removing different introns to produce different versions of a protein from a single gene
tRNA activating enzyme
attaches correct amino acid to the tRNA (requires ATP)(different enzyme for a new amino acid)
Polypeptides become proteins when its ___________ into its _____.
modified/folded, functional shape
Proteasomes:
enzyme complex that breaks down proteins into short polypeptides, which can be broken down into amino acids later on (requires enzyme, ATP)
Insulin is a polypeptide hormone
- preproinsulin
-modified:
-insulin codes for 110 amino acids
-rough ER removes 24 amino acids (Proinsulin)
-proinsulin is folded into tertiary structure with disulfide bonds - Some insulin removed from middles, leaves behind 2 linked chains with 51 amino acids (insulin)
Amino acids are joined together at the ___ site by a peptide bond.
P
Transcription (initiation)
RNA polymerase binds to a specific DNA sequence called a promoter.
Transcription (Elongation)
RNA polymerase synthesizes an RNA molecule (mRNA) by adding nucleotides to the growing chain, moving along the DNA template.
Transcription (Termination)
RNA polymerase reaches a termination signal, causing the RNA molecule and RNA polymerase to detach from the DNA.
Translation (Initiation)
The small ribosomal subunit binds to the mRNA molecule, and a tRNA molecule carrying an amino acid binds to the start codon on the mRNA.
Translation (Elongation)
The ribosome moves along the mRNA, adding amino acids to the growing polypeptide chain, guided by the codons on the mRNA.
Translation (Termination)
Translation stops when the ribosome reaches a stop codon on the mRNA, causing the release of the completed polypeptide chain.
