Terms to Know:
Adenine: One of the four nitrogenous bases in the DNA structure; pairs with
thymine in DNA and uracil in RNA
Amino Acid: What is transferred to the ribosome by the transfer RNA
Anti-codon: group of three bases on a transfer RNA molecule that are
complementary to a messenger RNA codon
Base Pairing: Principle that bonds in DNA and can form only between adenine
and thymine and between guanine and cytosine
Codon: three-nucleotide sequence on messenger RNA that codes for a single
amino acid
Cytosine: One of the four nitrogenous bases in the DNA structure; pairs with
guanine
Deletion: When a single nitrogen base is deleted, shifting the triple codon over
one
DNA: A structure used for long-term storage consisting of two strands
DNA helicase: unwinds the DNA strands during DNA replication
DNA ligase: proofreads the DNA during DNA replication
DNA polymerase: Enzyme involved in DNA replication that builds new DNA
strands
DNA Replication: Copying process by which a cell duplicates its DNA
Double Helix: Two strands of DNA wrapped together
Exon: segments of DNA that are expressed as genes
Frameshift Mutation: caused by insertion or deletion, shifting the entire triple
codon over one, this results in a mutation
Guanine: One of the four nitrogenous bases in the DNA structure; pairs with
cytosine
Insertion: when a single nitrogen base is inserted, shifting the triple codon over
one
Intron: ‘Junk DNA’ and are not expressed
mRNA: Acts as a “messenger” and carries a copy of the directions from the DNA
in the nucleus to the ribosome in the cytoplasm
Mutation: changes in the nucleotide sequence
Nitrogenous base: The four bases that create the base pairs; adenine, cytosine,
guanine and thymine
Nucleotide: Monomer of nucleic acids made up of a 5-carbon sugar, a
phosphate group, and a nitrogenous base
Phosphate: A type of acid in both nucleotides of DNA and RNA
Point Mutation: mutation that effects a single nucleotide
Polypeptide: Strand of amino acids produced during translation
Promoter: Where transcription begins
Purine: One of the two nitrogenous bases in the DNA structure; single and
consists of cytosine and thymine
Pyrimidine: One of the two nitrogenous bases in the DNA structure; double and
consists of adenine and guanine
Ribosome: Made of proteins
RNA: A structure used for short term storage consisting of only one strand
RNA polymerase: Attaches to a promoter and opens the DNA helix during
transcription
rRNA: Part of the ribosome; ribosome is made up of proteins and rRNA
Substitution: one nucleotide is substituted for another
Terminator: Transcription stops when RNA polymerase hits this structure
Thymine: One of the four nitrogenous bases in the DNA structure; pairs with
adenine
Transcription: process in which part of the nucleotide sequence of DNA is copied
into a complementary sequence in RNA; makes RNA
Transformation: Process in which one strain of bacteria is changed by a gene or
genes from another strain of bacteria
Translation: decoding of a mRNA message into a polypeptide chain; makes
proteins
tRNA: Transfers an amino acid to the ribosome