2.1.1 (k) - Prokaryotes vs Eukaryotes

Question 1

What are the general structural features of prokaryotes?

Answer 1

• No nucleus or membrane-bound organelles
• Small 18nm ribosomes
• No histones, just a single loop fo DNA
• Different to eukaryote, but has flagella
• Unicelullar

Question 2

What is the difference between DNA in a prokaryote (compared to eukaryote)?

Answer 2

• DNA structure same as eukaryotes, but packaged differently
  
  • Prokarytoes have 1 chromosome that is supercoiled and compact
• Genes organised into operons
  
  • Meaning genes switched on or off

Question 3

What are the features of ribosomes in prokaryotes?

Answer 3

• Has 70s ribosomes (smaller) compared to 80s ribosomes in eukaryotes

Question 4

What is the structure of a prokaryotic cell wall?

Answer 4

• Mde of peptidoglycan (aka murein)
• Polymer of amino acids and sugars

Question 5

What is the difference in the structure of prokaryotic flagella compared to eukaryotic?

Answer 5

• Not 9+2
• It is thinner in prokaryotes
• Filaments are rotated by energy from chemiosmosis (not from ATP like in eukaryotes

Question 6

What is consisted within the structure of a prokaryote?

Answer 6

Pili on the surface of the peptidoglycan cell wall Plasma membrane 70S ribosomes Free chromosomal DNA in the nucleoid region Flagellum