Molecular Genetics Flashcards
(36 cards)
Central Dogma
DNA -> RNA -> Proteins
Nucleotide
Deoxyribose, phosphate group, nitrogenous base
Purines
Adenine, Guanine (Larger, two-ring)
Pyrimidines
Cytosine, Thymine, Uracil (1 ring)
DNA Directionality
3’ -> 5’
T-A
Two hydrogen bonds
G-C
Three hydrogen bonds
DNA helicase
Breaks the hydrogen bonds between nitrogenous bases
Replication Fork
Opening in the DNA molecule created by DNA helicase
Topoisomerase
Removes the strain by cutting, twisting, rejoining the strands of DNA
Replication Bubble
The replication fork passed a portion of DNA, where the two strands are separated
DNA polymerase
Reads the parent DNA strand and creates a complementary, antiparallel strand, reads 3’->5’ (creates 5’->3’)
Leading strand
3’ end facing toward the replication fork
Lagging strand
3’ end facing away from the replication fork
Okazaki Fragments
Short fragments of synthesized DNA, joined together by DNA ligase
RNA
ribose, uracil, single-stranded
mRNA
Carries the complement of a DNA sequence
tRNA
Recognizes mRNA codon and amino acid
rRNA
Ribosomal machinery, most abundant
Transcription
RNA polymerase binds to the DNA template, promoter region, TATA box, and transcription factors assist
Post-transcriptional Processing
Hetero-nuclear RNA (pre-RNA), introns spliced out leaving exons, 5’ guanine cap and 3’ poly-A tail added, leave the nucleus
Stop Codons
UAA, UGA, UAG
Translation
Initiation, elongation, translocation, termination
Initiation
Small ribosomal subunits binds, start codon, methionine, complex is bound