lecture 6 Flashcards
DNA/RNA and biotechnology
what does a DNA nucleotide consist of
phosphate - sugar - base
what do DNA nucleosides consist of
sugar - base
what pairs with adenine (A) in a complementary DNA sequence
Thymine (T)
what pairs with cytosine (C) in a complementary DNA sequence
Guanine (G)
what is a hairpin structure
single palindromic DNA strand
what is a cruciform structure
double palindromic DNA strand
what is the secondary structure of DNA
the double helix
what is DNA folding
DNA helix wraps around a histone protein twice, forming a nucleosome. this is further packed into loops to form chromatin fibre which is folded into loops to form the chromosome
what is mRNA
messenger RNA - carries the code for making proteins. during transcription, DNA is unzipped and a single chain of pre-mRNA is made. this is processed into mRNA by removing the non-coding junk sequences. mRNA sequence is read 3 bases at a time to determine the order of amino acids in the protein chain
what is tRNA
transfers a specific amino acid to the ribosome. one end of tRNA binds to a specific amino acid and the other end binds to a specific codon in the mRNA sequence
what is denaturation
the separation of double-stranded DNA into randomly coiled strands
how do you know which DNA fragment has the highest percentage of CG nucleotides
the melting curve with the highest melting point
what is gel electrophoresis
used to identify DNA fragments based on their size and shape.
what are nucleases
enzymes that catalyse the hydrolysis of phosphodiester bonds to break apart DNA
how is DNA cloned
plasmid is cleaved by a restriction endonuclease - DNA fragment of interest cleaved from eukaryotic chromosome by a restriction endonuclease - DNA fragment of interest added to plasmid by DNA ligase to form recombinant vector which is inserted into bacterium. bacterial growth leads to cloning of recombinant DNA
