Structure of DNA and RNA

Question 1

What do DNA and RNA do?

Answer 1

-DNA holds genetic information
-RNA transfers genetic information from DNA to the ribosomes

Question 2

What sugars are found in DNA and RNA?

Answer 2

-DNA deoxyribose (has 1 less oxygen atom)
-RNA ribose

Question 3

What base is found in DNA but not in RNA, and what is it replaced by?

Answer 3

• thymine in DNA
  -replaced by uracil in RNA

Question 4

What bond is between the sugar and phosphate group?

Answer 4

phosphoester bond

Question 5

What bond forms when a condensation reaction occurs between two nucleotides?

Answer 5

phosphodiester bond

Question 6

What is the structure of DNA?

Answer 6

-helicoidal shape and double stranded
-H bonds formed between complementary bases

Question 7

How is the structure if DNA related to its function?

Answer 7

-double helix structure means it’s not easily effected by eternal environment
-lots of variation in sequence of bases creates great diversity
-complimentary base pairing means mutations are rare
-large and long molecule meaning it can carry immense amounts of information
-hereditary material so can be replicated and H bonds are weak so can be broken easily

Question 8

Why is DNA very stable?

Answer 8

-phosphodiester backbone protects the more chemically reactive organic bases
-H bonds link pairs forming bridges between phosphodiester backbones

Question 9

Compare nucleic acids

Answer 9

-DNA is double stranded, mRNA and tRNA are single polynucleotide chains
-DNA is the largest and tRNA is the smallest
-DNA is a double helix shape, mRNA is a single helix molecule, tRNA is clover shaped
-DNA is mostly found in the nucleus, mRNA and tRNA are manufactured in the nucleus but found throughout the cell
-DNA has the same quantity in all cells of species, mRNA and tRNA quantities vary from cells depending on level of metabolic activity