Transcription and Translation Flashcards
What is the function of DNA?
It contains the instructions required to make proteins.
Each gene has a special order of bases which codes for a protein. The order of bases on a person’s DNA id unique.
Except for identical twins.
What four bases make up the genetic code?
The four bases: adenine (A), thymine (T), cytosine (C), and guanine (G) make up the genetic code.
Relate amino acids to proteins.
Proteins are made of long chains of amino acids. Each protein is different because of the order of the amino acids. There are 20 different amino acids in total.
The base sequence determines the amino acid sequence of the protein.
Memorize.
The amino acid sequence determines the shape and therefore the function of the protein.
Memorize.
What is the role of mRNA in transcription?
Messenger RNA (mRNA) carries a complementary copy of the code from the DNA, in the nucleus, to a ribosome, where the protein is made. Base-pairing rules apply, but remember U replaces T on RNA.
What is a codon?
A set of three bases on a mRNA molecule is known as a codon. Each codon codes for one amino acid.
What is transcription?
The synthesis of mRNA from a DNA template (gene) in the nucleus.
When the DNA nucleotides are copied into segments of mRNA.
Transcription requires ATP (energy).
When does transcription occur?
Transcription occurs when a protein is needed by the body.
What are the steps of transcription?
- RNA polymerase (enzyme) unwinds DNA helix.
- RNA polymerase starts adding free free RNA nucleotides to form a strand of mRNA. It starts with a START codon and ends with a STOP codon. RNA nucleotides bond to adjacent DNA nucleotides via. complementary base pairing.
- Once the mRNA strand is complete. Hydrogen bonds can from between adjacent DNA nucleotides to reform the DNA double helix.
- The mRNA strand leaves the nucleus to go to the ribosome.
