DNA and RNA

Question 1

DNA

Answer 1

• deoxyribonucleic acid
• used to store genetic info
• all instructions needed to grow and develop from a fertilised egg to fully grown adult

Question 2

RNA

Answer 2

• ribonucleic acid
• main function is to transfer genetic info from DNA to ribosomes (made from RNA + proteins)
• need RNA to make polypeptides in a process called translocation

Question 3

nucleotide structure

Answer 3

• molecules of DNA and RNA are polymers of nucleotides

- biological molecules are made from 3 molecules: pentose sugars, nitrogen containing organic base and a phosphate group

Question 4

polynucleotide structure

Answer 4

• many nucleotides join together to form polynucleotide strands
• join up via condensation reactions between phosphate group of one nucleotide and the sugar of another
• forms phosphodiester bond
• chain of phosphate and sugars is knows as the sugar-phosphate backbone

Question 5

DNA structure

Answer 5

• double helix
• formed from 2 separate strands which wind around each together to form a spiral
• strands are polynucleotide
• made up from lots of nucleotides joined together in a long chain
• really long and coiled up very tightly
• a lot of genetic info can fit into a small space in the cells nucleus

Question 6

DNA nucleotide structure

Answer 6

• made from a phosphate group, pentose sugar deoxyribose and a nitrogen containing base
• each DNA nucleotide has same sugar and phosphate
• base on each nucleotide can vary though

Question 7

4 DNA bases

Answer 7

• Adenine A
• Thymine T
• Cytosine C
• Guanine G

Question 8

complementary base pairing

Answer 8

-2 polynucleotide strands join together by hydrogen bonds between bases
-each base can only join with one particular partner
-A-T
-G-C
2 polynucleotide strands antiparallel it twists to form a DNA double helix

Question 9

RNA structure

Answer 9

• is made of nucleotides that contain a sugar, a phosphate group and one of four different bases
• the nucleotides also form a polynucleotide strand with a sugar-phosphate backbone
• the sugar in the RNA nucleotides is a ribose sugar but still is a pentose sugar
• Uracil replaces Thymine as a base
• RNA form a single polynucleotide strand
• shorter than DNA