KA3- Gene Expression Flashcards
What is a gene?
A section of DNA which carries the code for the production of protein molecules
What does RNA splicing make genes do?
It can make a gene code for one protein or several different proteins
What is a genotype?
The genetic composition of a cell
What is phenotype determined by?
The proteins that are made when the gene is expressed
What do genes code for?
Proteins which perform all the functions required by each cell
What is genotype determined by?
The sequence of DNA bases in genes
What does gene expression involve?
The transcription and translation of DNA sequences to produce proteins
What is protein synthesis?
Using transcription and translation of DNA sequences to produce proteins
What does transcription involve?
Copying the sequence of bases in a gene to create mRNA
What does transcription create?
mRNA
What is translation?
When the sequence creates by transcription is turned into an amino acid sequence of a protein
What is RNA?
A nucleic acid
Why can RNA form complementary strands with DNA
As it has a similar structure to DNA
Is RNA double or single stranded?
Single
What does RNA have instead of thymine?
Uracil
What type of sugar do RNA nucleotides have?
Ribose
What are the three types of RNA?
mRNA
rRNA
tRNA
What does rRNA stand for?
Ribosomal RNA
What does tRNA stand for?
Transfer RNA
What does mRNA stand for?
Messenger RNA
What does mRNA carry?
A copy of the DNA code for a gene from the nucleus to ribosome
Where does mRNA a carry the copy of DNA code?
From the nucleus to the ribosome
How is a molecule of mRNA formed?
The base sequence of the gene is transcribed
What does each triplet of mRNA codon correspond to?
A specific amino acid
What is this series of codons translated into?
An amino acid sequence by the ribosomes in the cytoplasm
What is tRNA?
A single strand of rRNA that folds back on itself
What holds tRNA’s correct shape?
Complementary base pairing
What does each tRNA have?
An exposed triplet of bases at one end and an amino acid attachment site at the other
What is the correct name for the exposed triplet of bases on tRNA?
Anti-codon
What does each tRNA carry?
A specific amino acid to the ribosome
Why does tRNA carry a specific amino acid? It
So that it can be translated into a protein
What combines to form a ribosome?
rRNA name a protein
What is a ribosome?
The molecular machine that reads the mRNA code and assembles a protein
What does genetic code determine?
The sequence of amino acids in a protein
How many triplets are there in the genetic code?
64
How many different amino acids are found in proteins?
20
What does the sequence of amino acids determine?
The structure, shape and function of the produced protein
What is the first step of protein synthesis?
Copy a gene to form an mRNA molecule which is then spliced
What is the second step of protein synthesis?
The modified mRNA leaves the nucleus and moves to the cytoplasm
What is the third step of protein synthesis?
Ribosome attached to the mRNA and amino acids are lined up to form a polypeptide. The polypeptide folds to form a protein
