2.6 structure of DNA and RNA

Question 1

draw the basic structure of a nucleotide, labeling its parts

Answer 1

see paper

Question 2

differentiate between the different types of nitrogenous based

Answer 2

4 based in DNA are:
guanine
cytosine
adenine
thymine

RNA has Uracil (U) instead of thymine

G-C A-T via hydrogen bonds

Question 3

compare the structure of DNA and RNA

Answer 3

sugar: d- deoxyribose r-ribose
bases: d-has thymine r-has uracil
strands: d-double strands r-usually single stranded

Question 4

list 3 types of RNA

Answer 4

messenger RNA (mRNA) - an RNA copy of a DNA gene

transfer RNA (tRNA) - transfers amino acids to ribosomes

ribosomal RNA (rRNA) - the catalytic component of ribosomes

Question 5

outline with the aid of the diagram how nucleotides are linked together to form DNA strands

Answer 5

DNA nucleotides are linked by covalent phosphodiester bonds to form a long polynucleotide strand
5’—>3’

Two strands join together via complementary base pairing (G pairs with C via 3 hydrogen bonds, A pairs with T via 2 hydrogen bonds)

the two strands run anti parallel to each other in order for the bases to face each other and form hydrogen bonds

the double stranded DNA then twists into a double helix

each twist occurs every 10 nucleotides

Question 6

list 3 contributions of the following scientists to the elucidation of DNA structure

Answer 6

.

Question 7

describe how watson and crick proposed the structure of DNA via model making

Answer 7

they demonstrated that DNA strands were anti parallel and formed a double helix

also showed complementary base pairing