Transcription and Translation

mutation

A change in the nucleotide-base sequence of a gene or DNA molecule

nucleotide

A building block of DNA, consisting of a five-carbon sugar, a nitrogenous base and a phosphate group.

anticodon

group of three bases on a tRNA molecule that are complementary to an mRNA codon

replication

(genetics) the process whereby DNA makes a copy of itself before cell division

translation

(genetics) the process whereby messenger RNA directs the formation of a specific protein

RNA polymerase

Enzyme involved in DNA replication that joins individual nucleotides to produce an RNA molecule

codon

A specific sequence of three adjacent bases on a strand of DNA or RNA that provides genetic code information for a particular amino acid

Messenger RNA

A single stranded molecule. Copies the coded message from the DNA in the nucleus, and carries the message to the ribosome to make a protein.

promoter

A specific nucleotide sequence in DNA that binds RNA polymerase and indicates where to start transcribing RNA.

Ribosomal RNA

type of RNA that makes up the major part of ribosomes

Transcription

(genetics) the process whereby the DNA sequence is copied into mRNA

Transfer RNA

Carries amino acids to the ribosome and adds them to the growing protein after reading the mRNA

Point mutation

mutation that affects a single nucleotide, usually by substituting one nucleotide for another

frameshift mutation

Mutation that shifts the "reading" frame of the genetic message by inserting or deleting a nucleotide

Why is transcription important?

keeps dna safe in the nucleus and allows 1 gene to be amplified

steps for transcription

1. dna unwinds and splits open

2.rna polymerase adds rna nucleotides to the exposed bases on dna

3. this forms a new strand of mRNA

4. mRNA is edited introns are removed

Helicase

An enzyme that untwists the double helix of DNA at the replication forks.

Promoter

specific region of a gene where RNA polymerase can bind and begin transcription

introns

Noncoding segments of nucleic acid that lie between coding sequences.

Exons

Coding segments of eukaryotic DNA.

3 steps of translation

1. Initiation

2. Elongation

3. Termination