70 likes | 223 Views
Basic’s. There are 4 Nitrogenous Bases: Adenine (A) Guanine (G) Thymine (T) Cytosine (C). A always bonds with T G always bonds with C Think – “A Tall Girl Called”. Purine. Pyrimidine. 3’. 5’. G C. T A. C G. A T. 3’. 5’. Antiparallel Strands of DNA.
E N D
Basic’s • There are 4 Nitrogenous Bases: • Adenine (A) • Guanine (G) • Thymine (T) • Cytosine (C) A always bonds with T G always bonds with C Think – “A Tall Girl Called” Purine Pyrimidine 3’ 5’ G C T A C G A T 3’ 5’
Antiparallel Strands of DNA 5 “Prime” end 3 “Prime” end Notice: 2 strands of DNA run in opposite Directions!
Therefore… • The complementary strand of DNA… (5’)- TTCAGTACATTGCCA -(3’) IS… (3’)- AAGTCATGTAACGGT-(5’) Do the base pairing first… Then match up the 5’ with the 3’ ends. Remember - The nucleotide sequence is read from 5’ to 3’ Remember – complementary base pairing rules for DNA: A-T, C-G and RNA: C-G, A-U
Let’s Practice… • What is the correct sequence of RNA that results from the transcription of the DNA sequence (5’) GTTACGAAGTCT (3’) ? • First figure out the complementary bases • The sequence is read in the 5’ to 3’ direction • Answer is: • (5’) AGACUUCGUAAC (3’)