1.1) Structure of DNA

Question 1

• What is a ‘nucleotide’ made up of?

Answer 1

1. ➜ Phosphate
2. ➜ Deoxyribose Sugar
3. ➜ (Organic) Base

Question 2

• What is the ‘sugar-phosphate backbone’?

Answer 2

• The ‘sugar-phosphate backbone’ 🍦
  ➞ is when nucleotides form chemical bonds
  ↳ between the deoxyribose sugar and phosphate group 🧬
  ➜ forming the ‘sugar-phosphate backbone’.

Question 3

• What are ‘antiparallel strands’ and their features?

Answer 3

• ‘Antiparallel’ strands
  ➞ when 2 strands of DNA run in the opposite direction.
• The 3’ (three prime) strand
  ➜ always end on a deoxyribose sugar.
• The 5’ (five prime) strand
  ➜ always end on a phosphate group.

Question 3

• What are two different types of DNA and the two groups of DNA organisation (incl. examples)?

Answer 3

• CIRCULAR DNA: ⭕
  ➞ Prokaryotes (like bacteria 🦠)
  ↳ have a single, circular chromosome & smaller circular plasmids.
  ➜ (Yeast is a special example of a eukaryote as it also has plasmids).
• LINEAR DNA: ➖
  ➞ DNA 🧬
  ↳ found in eukaryotic cells is linear & found within the nucleus 🧫
  ➜ To allow the DNA to be organised effectively, it must be tightly coiled and packaged around bundles of proteins called histones.

Question 4

• REVIEW QUESTIONS:

1. Give an example of a prokaryotic and eukaryotic cell that contain plasmids:
   i. prokaryotic cell -
   ii. eukaryotic cell -
2. State where: i.) circular chromosomes and ii.) linear chromosomes could be find within the same eukaryotic cell.
   i.circular chromosomes -
   ii. linear chromosomes -

Answer 4

1. i. prokaryotic cell
   ➜ Bacteria 🦠
   ii. eukaryotic cell
   ➜ Yeast 🍞
2. i. circular chromosomes
   ➜ Chloroplasts or mitochondria
   ii. linear chromosomes
   ➜ Nucleus