Miller and Levine Biology Chapter 13: RNA and Protein Synthesis

RNA

single-stranded nucleic acid that contains the sugar ribose

messenger RNA

type of RNA that carries copies of the instructions for the assembly of amino acids into proteins from DNA to the rest of the cell

ribosomal RNA

type of RNA that combines with proteins to form ribosomes

transfer RNA

type of RNA that carries each amino acid to a ribosome during protein synthesis

transcription

synthesis of an RNA molecule from a DNA template

RNA polymerase

enzyme that binds to DNA, separates the DNA strands, and uses one DNA strand as a template to assemble nucleotides into a complimentary strand of RNA.

promoter

specific region of a gene where RNA polymerase binds and begins transcription

intron

sequence of DNA that is not involved in coding for protein and are cut out and discarded

exon

sequence of DNA that codes for a protein and is spliced together with other eons to form the final mRNA

polypeptide

long chain of amino acids that make proteins

genetic code

collection of codons of mRNA, each of which directs the incorporation of a particular amino acid into a protein during protein synthesis

codon

group of three nucleotide bases in mRNA that specify a particular amino acid to be incorporated onto a protein

translation

process by which the sequence of bases of an mRNA is converted into the sequence of amino acids of a protein

anticodon

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

gene expression

process by which a gene produces its product and the product carries out its function

mutation

change in the genetic material of a cell

point mutation

gene mutation in which a single base pair in DNA has been changed

frameshift mutation

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

mutagen

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

polyploidy

condition in which an organism has extra sets of chromosomes

operon

in prokaryotes, a group of adjacent genes that shares a common operator and promoter and are transcribed into a single mRNA

operator

short DNA region, adjacent to the promoter of a prokaryotic operon, that binds repressor proteins responsible for controlling the rate of transpiration of the operon

transcription factor

DNA-binding proteins that control gene expression by binding sequences in regulatory regions of genes

RNA interference (RNAi)

introduction of the double-stranded RNA into cells to inhibit gene expression

differentiation

process in which cells become specialized in structure and function

homeotic gene

a class of regulatory genes that determine the identity of body parts and regions in an animal embryo. Mutations in these genes can transform one body part into another

homeobox gene

A type of homeotic gene that contains a specific DNA sequence of about 130 base pairs (the homeobox) and codes for transcription factors that activate other genes important in cell development and differentiation

Hox gene

a group of homeotic genes clustered together that determine the head to tail identity of body parts in animals. All box genes contain the homeobox DNA sequence