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

Brief description of DNA: (two points)

Answer 4

DNA is a polymer with a double helix structure

Question 5

What monomer makes up DNA?

Answer 5

Nucleotide

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

What can the nitrogenous bases be? (four options)

Answer 7

Guanine, Cytosine, Adenine and Thymine

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 condensation reactions. By forming a bond between the phosphate group and the pentose sugar (deoxyribose)

Question 10

Explain how a bond is formed between nucleotides: (two points)

Answer 10

The bond is formed through multiple condensation reactions. The condensation reactions occur between the deoxyribose sugar and the phosphate group, which create a phosphodiester bond

Question 11

What is a phosphodiester bond?

Answer 11

A phosphodiester bond is a strong covalent bond that helps ensure the genetic code is not broken down

Question 12

What forms the genetic code?

Answer 12

The nitrogenous bases form the genetic code

Question 13

What is the sugar phosphate backbone? What has a sugar phosphate backbone?

Answer 13

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

Question 14

How does the DNA polymer occur? What does the DNA polymer form in structure?

Answer 14

The DNA polymer occurs in pairs, which join together by hydrogen bonds between the bases. The DNA polymer forms a double helix structure

Question 15

Where do the hydrogen bonds form between?

Answer 15

The hydrogen bonds form between complementary base pairs

Question 16

What does each nitrogenous base pair with?

Answer 16

Adenine and thymine forms a hydrogen bond

Guanine and cytosine form a hydrogen bond

Question 17

How many hydrogen bonds are formed between each nitrogenous base?

Answer 17

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

Question 18

Why are the complementary base pairs important?

Answer 18

The complementary base pairing is important to help maintain the order of the genetic code when DNA replicates

Question 19

How does the structure relate to function?

Answer 19

1. The complementary base pairing allows identical copies to be made
2. DNA being a large molecule enables it to carry lots of information
3. The hydrogen bonds are weak so when DNA replication occurs the bonds will be easily broken and the replication of DNA can easily be done
4. The molecule is double stranded so when DNA replication occurs one strand can act as an template
5. DNA has a stable structure due to the phosphodiester bonds which create a sugar-phosphate backbone, leading to the formation of a double helical structure. This structure means the strong covalent bonds are on the outside of the helix, leaving the weaker hydrogen bonds in the middle of the helix, protected.