DNA, RNA, Protein Synthesis Flashcards
(42 cards)
Describe two differences between tRNA and mRNA
tRNA is clover leaf shape, mRNA is linear
tRNA has amino acid binding site and mRNA does not
tRNA has anticodon and mRNA has codon
How is the structure of pre-mRNA different to the mRNA used in translation?
Pre-mRNA has both exons and introns which then undergoes splicing to remove the non-coding introns leaving only exons as mRNA used in translation
Describe the structure of mRNA
A long single strand. Its base sequence is complementary to the DNA It was transcribed from.
Describe the structure of tRNA
clover leaf shape
One end is an anticodon and the opposite end is an amino acid binding site
Outline the process of transcription
DNA double helix unwinds hydrogen bonds are broken by DNA helicase.
These strands are separated and the DNA molecule uncoils exposing some of the bases
One strand is used as a template for free RNA nucleotides to lineup to their complimentary bases. It is joined by RNA polymerase.
What is RNA polymerase
Catalyses the formation of
Phosphodiester bonds between DNA bases and adjacent RNA nucleotides
Outline the process of translation
mRNA attaches itself to a ribosome.
The anticodon on tRNA attaches to complementary bases on the mRNA. Specific amino acid carried by tRNA form peptide bonds continuing to form a polypeptide chain along the codons into a stop codon is reached. this process requires ATP.
What does degenerate mean?
There is excess capacity of the DNA code. More than one triplet for each amino acid.
What is the structure of DNA?
DNA is a double helix composed of two strands of nucleotides.
What are the four nucleotide bases in DNA?
Adenine (A), Thymine (T), Cytosine (C), and Guanine (G).
True or False: RNA contains Thymine.
False. RNA contains Uracil instead of Thymine.
What is the primary function of RNA?
To act as a messenger carrying instructions from DNA for controlling the synthesis of proteins.
Fill in the blank: The process of copying DNA into RNA is called __________.
transcription.
What are the three types of RNA?
Messenger RNA (mRNA), Transfer RNA (tRNA), and Ribosomal RNA (rRNA).
What is the role of tRNA in protein synthesis?
tRNA transports amino acids to the ribosome during translation.
Which enzyme is responsible for synthesizing RNA during transcription?
RNA polymerase.
True or False: Each amino acid is coded for by a three-nucleotide sequence called a codon.
True.
What is the process of translating mRNA into a protein called?
Translation.
Fill in the blank: The sequence of nucleotides in DNA determines the sequence of __________ in proteins.
amino acids.
What is the function of ribosomes in protein synthesis?
Ribosomes make the proteins by translating the mRNA code into an amino acid sequence
What are introns?
Non-coding sequences in a gene that are removed during RNA splicing.
What is the difference between prokaryotic and eukaryotic transcription?
In prokaryotes, transcription occurs in the cytoplasm, while in eukaryotes, it occurs in the nucleus.
Fill in the blank: The process of removing introns and joining exons together is called __________.
splicing.
What is a mutation?
A random change in the DNA sequence that can lead to changes in the protein produced.
