DNA structure/function

Question 1

What does DNA stand for?

Answer 1

DNA stands for deoxyribonucleic acid

Question 2

What does DNA code for?

Answer 2

DNA codes for the sequence of amino acids in the primary structure of proteins

Question 3

What does the primary structure of a protein determine?

Answer 3

The primary structure determines the final 3D structure and function of a protein

Question 4

What monomer makes up DNA?

Answer 4

Nucleotide

Question 5

Draw the structure of a nucleotide (freeform)

Answer 5

Draw the structure of a nucleotide (freeform)

Question 6

What is a nucleotide made up of?

Answer 6

A pentose sugar (deoxyribose), a phosphate group and a nitrogenous containing base (cytosine, guanine, adenine and thymine)

Question 7

Label the structure of a nucleotide freeform

Answer 7

freeform answer

Question 8

What is a polymer of nucleotide?

Answer 8

A polynucleotide

Question 9

How do nucleotides join together?

Answer 9

Nucleotides join together through multiple condensation reactions.

Question 10

How is a polynucleotide formed?

Answer 10

Polynucleotides are formed from multiple condensation reactions between nucleotides, which involve the removal of a water molecule and the formation of a phosphodiester bond

Question 11

What is a phosphodiester bond and what is it’s importance in DNA?

Answer 11

Phosphodiester bonds are strong covalent bonds, and prove important in DNA because they ensure the genetic code is not broken down

Question 12

Brief description of DNA: (two points)

Answer 12

DNA is a polymer with a double helix structure

Question 13

What forms the genetic code?

Answer 13

The nitrogenous bases form the genetic code

Question 14

What is the sugar phosphate backbone?

Answer 14

The sugar phosphate backbone has strong covalent bonds between the sugar and phosphate groups that hold the polymer together

Question 15

What does each nitrogenous base pair with?

Answer 15

Adenine and thymine forms a hydrogen bond

Guanine and cytosine form a hydrogen bond

Question 16

How many hydrogen bonds are formed between each nitrogenous base?

Answer 16

Adenine and thymine forms 2 hydrogen bonds
Whereas cytosine and guanine form three hydrogen bonds

Question 17

Describe the formation of the double helix structure of a DNA molecule

Answer 17

The DNA polymer occurs in pairs, which are joined together by hydrogen bonds, that have formed between complementary bases

Question 18

How does the structure relate to function?

Answer 18

1. DNA being a large molecule enables it to carry lots of information
2. The hydrogen bonds are weak so when DNA replication occurs the bonds will be easily broken, making replication more efficient
3. DNA has a stable structure due to the phosphodiester bonds which create the sugar phosphate backbone. This structure means the strong covalent bonds on the outside of the helix, leaving the weaker hydrogen bond in the middle of the helix protected
4. DNA is double stranded so replication can occur using one strand as a template

5.Complementary base pairing allows identical copies of DNA to be made