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autosomal recessive trait where individuals lack the enzyme to break down homogentisic acid; characterized by black urine


bread mold used by Beadle and Tatum to show that mutation in a specific gene caused loss of activity in a specific enzyme

Diversity of Proteins

results from the number of possible combinations of the 20 different amino acids


intermediary between genes and phenotype


triplet of nucleotides in mRNA that encode the information for a specific amino acid

T4 Genes

used by Crick & Brenner to discover the number of nucleotides required to encode one amino acid

Stop Codon

signals the end of protein synthesis


single-stranded copy of the nucleotide sequence in a gene


transfer of information from the base sequence of DNA to the base sequence of RNA; occurs in nucleus


conversion of information encoded in the nucleotide sequence of an mRNA molecule into the linear sequence of amino acids in a protein; occurs in cytoplasm

Transcription Initiation

an enzyme called RNA polymerase binds to a specific nucleotide sequence in the DNA adjacent to a gene and unwinds the DNA

Promoter Region

region of a DNA molecule to which RNA polymerase binds and initiates transcription

Polymerase I

catalyzes transcription for rRNA formation

Transcription Elongation

RNA polymerase links RNA nucleotides together, forming mRNA

Terminator Region

nucleotide region that signals the end of transcription


DNA sequences that are transcribed but removed during processing; noncoding


DNA sequences that are transcribed and translated into an amino acid sequence


precursor molecule that are processed in the nucleus to remove introns, or cut and spliced to remove introns


modified base attached to the 5' end of mRNA

Poly-A Tail

series of A nucleotides added to the 3' end of mRNA

Amino Group

chemical group (NH2) found in amino acids and at one end of the polypeptide chain

Carboxyl Group

chemical group (COOH) found in amino acids and at one end of the polypeptide chain

Peptide Bonds

covalent chemical link between carboxyl and amino groups of two different amino acids


molecule made of ten or more amino acids joined together with peptide bonds


end of a polypeptide or protein that has a free amino group


end of a polypeptide or protein that has a free carboxyl group


cytoplasmic particles composed of two units that are the site of protein synthesis


RNA molecule that forms part of the ribosome


contains a binding site for a specific type of amino acid and has a three-base segment that recognizes a specific base sequence in mRNA


group of three nucleotides in a tRNA molecule that pairs with a complementary sequence in an mRNA molecule

Initiation Complex

formed by a combination of mRNA, tRNA, and the small ribosomal subunit


set of proteins present in a particular cell at as specific time under a particular set of environmental conditions

Primary Structure

amino acid sequence in a polypeptide chain; still linear

Tertiary Structure

3D structure of a protein molecule brought about by folding on itself

Secondary Structure

pleated structure in a protein molecule brought about by bonds between amino acids

Quaternary Structure

structure formed by the interaction of two or more polypeptide chains in a protein

Protein Functions

muscle contraction, transport, immune response, nerve impulse transmission, phenotypes of cells/tissues/organisms


protein folded into an infectious conformation that is the cause of several disorders

Mad Cow Disease

prion disease of cattle


molecules that can fit into the three-dimensional shape of an enzyme

Phenylalanine Hydroxolase

the enzyme that catalyzes the conversion of phenylalanine to tyrosine


the enzyme that catalyzes the breakdown on sugar lactose


lowers the energy of activation required in biochemical reactions

Genetic Disorders

absence or changes to the protein functions; mutant phenotypes

Amount of Info Stored in a Cell

related to the number of nucleotides within a cell

Protein Diversity

stems from possible combinations of the 20 amino acids


points on the polypeptide chain mirror points on the gene; if there is a break toward the end of the gene, the chain will have a break t the same point


the last position can vary, but the codon will still create the same amino acid

Polymerase II

catalyzes transcription for mRNA formation

Polymerase III

catalyzes transcription for tRNA formation


sequences that allow polymerases to bind to the DNA strand before reaching the open reading frame

Open Reading Frame

a stretch of consecutive codons undisrupted by a termination codon

Heterogeneous Nuclear RNA

newly synthesized RNA

Alternative Splicing

allows for the possibility that a single gene can produce more than one type of protein

Direction to Read a Polypeptide

from N-terminus to C-terminus


assist in the folding of newly synthesized proteins

Post-Translational Modification

process in which polypeptides are chemically modified after being created

Beta Sheet

the backbone of this particular secondary structure looks like an accordion

Creutzfeldt-Jakob Disease

human version of mad cow disease; brain looks like a sponge

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