Protein Synthesis Flashcards
What are the names of the four nitrogenous bases found in DNA?
- Adenine
- Thymine
- Guanine
- Cytosine
What are the names of the four nitrogenous bases found in RNA?
- Adenine
- Uracil
- Guanine
- Cytosine
Why is the nitrogenous base Thymine present in DNA but not RNA?
In the nucleus of a cell, Uracil is easily mutated, this means that Uracil is an unsuitable organic base for DNA, Thymine however is not easily
mutated in the cell’s nucleus therefore is a more suitable match to act as a base in DNA.
Why is the nitrogenous base Uracil present in RNA but not DNA?
In the cell’s cytoplasm, Thymine is easily broken down by the chemical compounds present in the cytoplasm however Uracil is not as easily broken down therefore Uracil is a more suitable match due to RNAs role in protein synthesis.
What is the name of the pentose sugar found in DNA?
Deoxyribose
What is the name of the pentose sugar found in RNA?
Ribose
What are the three major components of a nucleotide?
- A phosphate group
- A pentose sugar
- A nitrogenous base / Organic base
What is the name of the reaction that joins nucleotides together?
A condensation reaction
What is the name of the bond that is created between nucleotides during a condensation reaction?
A phosphodiester bond
What is the function of mRNA?
To take DNA information from the nucleus to the ribosomes where it an be used in protein synthesis
What are the three types of RNA present in a cell?
- mRNA (Messenger RNA)
- tRNA (Transfer RNA)
- rRNA (Ribosomal RNA)
Describe the structure of mRNA.
mRNA is in a single stranded helix structure.
How does the enzyme RNA Polymerase work?
RNA Polymerase binds to DNA and runs along it, breaking the hydrogen bonds between the complimentary base pairs.
What is the name given to the strand of DNA that is used in the production of RNA?
The template strand
Once RNA Polymerase has added two nucleotides to bases in the template strand, what is the next step in production of RNA?
The two nucleotides that have been added by RNA Polymerase are joined together via a condensation reaction which forms a phosphodiester bond between the two nucleotides.
What happens to the previous DNA as the RNA Polymerase moves along the DNA.
The double helix structure is reintroduced to the two separated strands.
Once the RNA strand is complete, what happens to the RNA strand and the RNA Polymerase?
The RNA and RNA Polymerase both detach from the DNA.
What is the name for the process in which a strand of RNA is produced?
Transcription
What is the name given to the strand of RNA that is produced by transcription?
Pre-mRNA
What happens during the first stage of transcription?
During the first stage of transcription, RNA Polymerase breaks hydrogen bonds between complimentary DNA bases.
What happens during the second stage of transcription?
During the second stage of transcription, RNA Polymerase adds RNA nucleotides to complimentary bases on one strand of DNA (the template strand). These nucleotides are joined together by a condensation reaction which forms phosphodiester bonds between the nucleotides.
What happens during the final stage of transcription
Reattachment of the DNA strands into the double helix structure which leaves a strand of Pre-mRNA completed.
What is the definition of a gene?
A gene is a base sequence of DNA that codes for the amino acid sequence of a polypeptide.
What is the name given to a sequence in a gene that is non-coding?
An intron
What is the name given to a sequence in a gene that is coding?
An exon
What happens during splicing of Pre-mRNA?
During splicing, a group of proteins cluster around the Pre-mRNA which removes the introns, the remaining exons are then attached together. This is because introns are not needed in mRNA due to them being non-coding.
What is the name given to each set of three bases in a strand of DNA and mRNA?
A triplet
In DNA, each triplet codes for how many amino acids?
1
In DNA and mRNA, the genetic code as a whole is…
- Degenerate
- Non-overlapping
- Universal
Why is the genetic code in DNA and mRNA known as universal?
The genetic code in DNA is known as universal due to all organisms coding for one amino acid using a triplet.
Why is the genetic code in DNA and mRNA known as degenerate?
The genetic code in DNA is known as degenerate because different triplets within the genetic code can code for the same amino acid.
Why is the genetic code in DNA and mRNA known as non-overlapping?
The genetic code in DNA is known as non-overlapping because each base is only read once as to not overlap and code for too many amino acids.
In mRNA, what is the name given to three bases that code for a specific amino acid?
A codon
During transcription, each triplet in DNA results in…
a complimentary codon on mRNA.
