DNA replication, transcription and RNA prcoessing Flashcards
what does antiparallel mean?
2 polynucleotide DNA strands have opposite polarity
what is meant by semiconservative?
each new DNA double helix is made from one original strand (from parental helix)and one newly made strand
what is enzyme responsible for DNA replication?
DNA polymerase (DNA replication fork)
what direction does DNA synthsis occur in and why?
5’-3’ direction because an incoming nucleotide can only be added to 3’ carbon of deoxyribrose
what are the strands on replicating DNA?
leading - continuous replication
lagging (produce ozaki fragments) - discontinuous replication
what initiates DNA replication ?
primers (RNA)
what enzyme unwinds parental DNA?
DNA helicase
what are SSBPs?
single-stranded binding proteins
they maintain inwound DNA structure
what enzyme detaches primer?
ribonuclease H
what enzyme links ozaki fragments?
DNA ligase (covalent bonds)
what are 2 steps in gene expression?
transcription and translation
name 3 strutcural differences between RNA and DNA?
RNA is a single strand, DNA is double.
RNA contains ribrose sugar, DNA sugar is deoxyribrose
RNA has uracil, DNA has thymine
what are 3 phases in eukaryotic transcription?
initiation, elongation, termination
what initiates RNA transcription?
binding of RNA polymerase to promotor region/sequence.