In: Biology
1. One strand of a double-helical DNA has the sequence 5¢-GCGCAATATTTCTCAAAATATTGCGC-3¢. Write the base sequence of the complementary strand. What special type of sequence is contained in this DNA segment? Does this double-stranded DNA have the potential to form any alternative structures?
2. Compositional analysis of a certain lipid shows that it has exactly one mole of fatty acid per mole of inorganic phosphate. What could be the identify of this lipid? Explain.
1)The given coding strand is 5' GCGCAATATTTCTCAAAATATTGCGC3'
Template strand is 3' CGCGTTATAAAGAGTTTTATAACGCG 5
Complimentary strand will be 5' GCGCAATATTTTGAGAAATATTGCGC 3' ( when you are writing the single strand,must write it in the direction 5' to 3')
The speciality of this DNA sequence is palindrome and these sequence are inverted, repeat with two fold symmetry( can be equally divided).
coding strand : 5' GCGCAATATTTCTCAAAATATTGCGC 3'
Template strand : 3' CGCGTTATAAAGAGTTTTATAACGCG 5'
This sequence is self complemtary and they have the potential to from hairpin structure.This sequnce can also form cruciform. structure when these two strands are combined(put together).
2),The answer is Sphingolipids( sphingomycelin), it has one fatty acid molecule and a phosphocholine molecule attached to the sphingosine backbone, and the ratio of fatty acid to the inorganic phosphate is 1:1,. Glycerophospholipids have 2 fatty acid chains and one phosphate group, so the ratio of fatty acid to inorganic phosphate will be 2:1.