Molecular Biology

transcription

DNA to mRNA

translation

mRNA to proteins

histones

the proteins that DNA wraps around

hereditary

inherited

somatic

mutations in body cells, not inherited

mutagens

substances that cause DNA to mutate

frameshift mutation

insertion or deletion of nucleotide bases in a DNA sequence that alters the reading frame of the genetic code, potentially leading to significant changes in the resulting protein.

benign

have no effect

germline

mutations in the sperm or egg cells

base substitution

a type of mutation where one nucleotide is replaced by another in the DNA sequence, which may or may not affect protein function.

stem cells

undifferentiated cells capable of giving rise to various cell types.

nonsense

the substitution leads to a stop codon

silent

no change in amino acid

missense

amino acid changes

methylated

tightly packed DNA, gene turned off

acetylated

uncoiled DNA, gene turned on

transcription factors

protein “switches” that can turn on/off a gene and either activate or repress RNA polymerase from doing transcription.

pyrimidine

a class of nitrogenous bases that includes cytosine, thymine, and uracil.

purine

a class of nitrogenous bases including adenine and guanine.

plasmid

a circular DNA molecule found in bacteria that replicates independently

topoisomerase

alters the supercoiling of DNA strands

lacoperon

a series of genes in E. coli that allow the bacteria to utilize lactose for energy when glucose is not available

trp operon

a group of genes in E. coli that work together to produce the amino acid tryptophan