Biology - DNA Vocab

adenine

one of two purine nucleobases used in forming nucleotides of the nucleic acids; adenine bonds to thymine via two hydrogen bonds; in RNA adenine binds to uracil

anticodon

a region of tRNA that consists of three bases complementary to the codon of mRNA

base pairing

principle that states that bonds in DNA can form only between adenine and thymine and between guanine and cytosine

codon

in DNA, a three-nucleotide sequence that encodes an amino acid or signifies a start signal or a stop signal

cytosine

one of the two pyrimidine bases found in DNA and RNA that binds with guanine via three hydrogen bonds

deletion mutation

segments of a gene are lost, often during meiosis

deoxyribonucleic acid (DNA)

genetic material that organisms inherit from their parents

differentiation

process in which cells become specialized in structure and function

DNA Polymerase

principal enzyme involved in DNA replication

exon

the portion of the DNA sequence in a gene that contains the sequence of amino acids in a chain and the beginning and the end of a coding sequence

frameshift mutation

a mutation that causes a gene to be read in the wrong three-nucleotide sequence

gene alteration

mutations that change a gene

gene expression

the manifestation of the genetic material of an organism in the form of specific traits

genetic code

the rule that describes how a sequence of nucleotides, read in groups of three consecutive nucleotides (triplets) that correspond to specific amino acids, specifies the amino acid sequence of a protein

guanine

a purine base found in DNA and RNA; usually paired via three hydrogen bonds with cytosine

insertion mutation

a sizable length of DNA is inserted into a gene

intron

a section of DNA that does not code for an amino acid and that is transcribed into RNA but is removed before it is translated

lac operon

a gene system whose operator gene and three structural genes control lactose metabolism in E. Coli

messenger RNA

a single stranded RNA molecule that encodes the information to make a protein

mutagen

chemical or physical agents in the environment that interact with DNA and may cause a mutation

mutation

change in the genetic material of a cell

nitrogenous base

bases that contain nitrogen; DNA has four adenine, cytosine, guanine, and thymine

nucleotide

subunit if which nucleic acids are composed; made up of a 5-carbon sugar, a phosphate group, and a nitrogenous base

operon

a unit of gene regulation and transcription in bacterial DNA that consists of a promoter, an operator, and one or more structural genes

phosphate group

a phosphorus atom bound to four oxygen atoms; alternates with a sugar to form the backbone of DNA

point mutation

a mutation in which only one nucleotide or nitrogenous base in a gene is changed

polyploidy

condition in which an organism has an extra set of chromosomes

promoter

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

replication

process of copying DNA prior to cell division

repressor

a regulatory protein that binds to an operator and blocks transcription of the genes of an operon

ribonucleic acid (RNA)

a natural polymer that is present in all living cells and that plays a role in protein synthesis

ribosomal RNA

an organelle that contains most of the RNA in the cell and that is responsible for ribosome function

RNA interference

introduction of double-stranded RNA into a cell to inhibit gene expression

RNA Polymerase

an enzyme that starts (catalyzes) the formation of RNA by using a strand of a DNA molecule as a template

telomeres

the tip of eukaryotic chromosome

thymine

a pyrimidine base that pairs with adenine in DNA ; replaced with uracil in RNA

transcription

the process of forming a nucleic acid by using another molecule as a template; particularly the process of synthesizing RNA by using one strand of a DNA molecule as a template

transfer RNA

an RNA molecule that transforms amino acids to the growing end of a polypeptide chain during translation

translation

codons in mRNA molecules to specify the sequence of amino acids in polypeptide chains

uracil

one of the four bases that combine with sugar and phosphate to form a nucleotide subunit of RNA; uracil pairs with adenine

dys-

bad, difficult

-ectomy

cut out

em-, en-, endo-

in, into

-emia

blood

entero-

intestine