Chapter 4 vocab Flashcards
complimentary base pairing
hydrogen bonding between purines (a and t), and pyrimidines (c and g)
DNA helicase
enzyme that unwinds the DNA strands by breaking H-bonds between base pairs
DNA polymerase
enzyme that positions and joins new complimentary DNA nucleotides into place during DNA replication
nucleotide
a molecular complex of three subunits; phosphate, pentose sugar and a nitrogen containing base
recombinant DNA
contains DNA from two or more different sources
replication
the process of copying one DNA helix into two identical helices
semi-conservative replication
after DNA replication, a new double helix has one conserved old template strand and one new strand
amino acid
an organic molecule composed of an amino group and an acidic group
anti-codon
a triplet of three bases complimentary to the mRNA codon
codon
a triplet nucleotides in mRNA that either codes for a particular amino acid or signals polypeptide termination
DNA sequence
a succession of letters that indicate the order of nucleotides within a DNA molecule
elongation
the second step of protein synthesis where the polypeptide chain is created one amino acid at a time
environmental mutagen
environmental influences that cause mutations in humans
genetic disorder
an illness caused by one or more abnormalities in the genome i.e. sickle cell mutation
initiation
first step of protein synthesis, all translation components are brought together
mRNA function
a RNA molecule is formed by copying DNA (with uracil instead of thymine). RNA travels through the nuclear pores to the ribosome where proteins are formed.
mutation
a permanent change in the sequence in the sequence of bases in the DNA; either germ-like or somatic
polypeptide chain
a chain of amino acids that are joined by peptide bonds
ribosomes
composed of two subunits, involved in synthesis of proteins using mRNA as a template
termination
final step of protein synthesis, polypeptide and assembled components that carried out protein synthesis are separated from one another
transcription
the first step of gene expression; process where ta portion of DNA serves as a template for mRNA formation
tRNA
a nucleic acid containing a sugar ribose responsible for bringing the amino acid to the ribosome for protein formation
translation
during gene expression, the process where the sequence of mRNA bases determine the sequence of amino acids in a polypeptide
