Bio Ch 12 Flashcards
Pyrimidine
thymine & cytosine (single ring)
Purine-based nucleotides
adenine & guanine (double ring)
Double helix
double spiral; describes the 3D shape of DNA
Complementary base pairing
a purine (large, 2-ring base) is always bonded to a pyrimidine (smaller, one-ring base)
DNA Replication
process of copying a DNA molecule
Template
most often a mold used to produce a shape complementary to itself
Semiconservative replication
each daughter DNA double helix contains an old strand from the parental DNA double helix and a new strand
DNA Polymerase
during replication, an enzyme that joins the nucleotides complementary to a DNA template
telomeres
special nucleotide sequence that does not code for proteins; use a repeat sequence such as TTAGGG
Replication fork
in eukaryotic DNA replication, the location where the 2 parental DNA strands separate
Uracil
in RNA, this base replaces the thymine found in DNA
Messenger RNA (mRNA)
takes a message from DNA in the nucleus to the ribosomes in the cytoplasm
Transfer RNA (tRNA)
transfers amino acids to the ribosomes
Ribosomal RNA (rRNA)
along with ribosomal proteins, makes up the ribosomes, where polypeptides are synthesized
Transcription
process by which an RNA molecule is produced based on a DNA template; DNA is copied, base by base, into mRNA, tRNA, & rRNA