adenine

(biochemistry) purine base found in DNA and RNA

amino acid

basic building block of protein

anticodon

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

cell cycle

series of events that cells go through as they grow and divide

chromosome

threadlike structure within the nucleus containing the genetic information that is passed from one generation of cells to the next

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

cytosine

Nitrogen base that pairs with guanine.

deoxyribose

five-carbon sugar that is a component of DNA nucleotides

DNA

deoxyribonucleic acid

DNA Polymerase

enzyme involved in DNA replication that joins individual nucleotides to produce a DNA molecule

double helix

two strands of nucleotides wound about each other; structure of DNA

enzyme

specialized proteins that speed up chemical reactions

exon

sequence of a gene's DNA that transcribes into protein structures

gene/genome/genetic code

(genetics) a segment of DNA that is involved in producing a polypeptide chain

guanine

The base that pairs with Cytosine in DNA

helicase

an enzyme that untwists the double helix at the replication forks, separating the two parental strands and making them available as template strands

histone

protein molecule around which DNA is tightly coiled in chromatin

hydrogen bond

the bond between the nitrogenous bases of DNA

intron

sequence of DNA that is not involved in coding for a protein

lagging / leading strands

DNA strand that must be synthesized during replication in the direction opposite from the replication fork

ligase

An enzyme that connects two fragments of DNA to make a single fragment; also called DNA ligase. This enzyme is usedd during DNA replication and is also used in recombinant DNA research.

mRNA

messenger RNA; type of RNA that carries instructions from DNA in the nucleus to the ribosome

nitrogenous base

an organic base that contains nitrogen, such as a purine or pyrimidine; a subunit of a nucleotide in DNA and RNA

nucleic acid

an organic compound, either RNA or DNA, whose molecules are made up of one or two chains of nucleotides and carry genetic information

nucleosome

bead-like structure in eukaryotic chromatin, composed of a short length of DNA wrapped around a core of histone proteins

nucleotide

Monomer of nucleic acids made up of a 5-carbon sugar, a phosphate group, and a nitrogenous base

Okazaki Fragments

Short fragments of DNA that are a result of the synthesis of the lagging strand during DNA replication.

peptide bonds

Bonds between amino acids

phosphodiester bond

Strong covalent bond holding the carbon-3 atom of one nucleotide (deoxyribose sugar) to the phosphate group of another nucleotide

polypeptide

A polymer (chain) of many amino acids linked together by peptide bonds.

protein synthesis

the formation of proteins by using information contained in DNA and carried by mRNA

purine

a nitrogenous base that has a double-ring structure; one of the two general categories of nitrogenous bases found in DNA and RNA; either adenine or guanine

pyrimidine

a nitrogenous base that has a single-ring structure; one of the two general categories of nitrogenous bases found in DNA and RNA; thymine, cytosine, or uracil

replication

copying process by which a cell duplicates its DNA

ribose

a five-carbon sugar present in RNA

ribosome

small particle in the cell on which proteins are assembled; made of RNA and protein

RNA Polymerase

enzyme similar to DNA polymerase that binds to DNA and separates the DNA strands during transcription

rRNA

ribosomal RNA; type of RNA that makes up part of the ribosome

semi-conservative

method of replication that implies that each new strand of DNA is half original and half new

template

a model or standard for making comparisons

thymine

a base found in DNA (but not in RNA) and derived from pyrimidine

transcription

(genetics) the organic process whereby the DNA sequence in a gene is copied into mRNA

translation

(genetics) the process whereby genetic information coded in messenger RNA directs the formation of a specific protein at a ribosome in the cytoplasm

tRNA

transfer RNA; type of RNA that carries amino acids to the ribosome

uracil

a nitrogen-containing base found in RNA (but not in DNA) and derived from pyrimidine