2.1.1 Cell Structure – Prokaryotes and Eukaryotes Flashcards
(10 cards)
What are the two key features of prokaryotes?
- They have no nucleus, their DNA is free in the cytoplasm.
- They have no membrane-bound organelles e.g. mitochondria, golgi apparatus etc.
Which two kingdoms of organisms are both prokaryotes?
Bacteria and archaea.
How is the DNA organised inside a prokaryote?
Into one long loop of DNA – one single chromosome.
Which organelles does a prokaryote have in common with eukaryotic cells?
Cell surface membrane, cell wall, cytoplasm, ribosomes.
What is the cell wall of a prokaryote made from?
Peptidoglycan – (also known as murein) a molecule made of amino acids and sugars.
What is a plasmid?
A small continuous loop of DNA, that contains non-essential DNA.
What is a pilus?
A structure that allows one prokaryotic cell to connect with another. A pilus can often be used to transfer/share plasmids between bacteria.
Singular = pilus
Plural = Pili.
What do prokaryotes use flagella for?
For movement – to move themselves.
What is a mesosome?
Infoldings of the cell surface membrane of the prokaryote. Many reactions take place on this membrane, including respiration, and in some bacteria a form of photosynthesis.
What is the difference between prokaryotic and eukaryotic ribosomes?
Prokaryotic ribosomes are smaller. Prokaryotic ribosomes are known as 70S ribosomes, whereas eukaryotic ribosomes are 80S. This is a measure of how heavy they are.
