2.1.1 Cell Structure – Prokaryotes and Eukaryotes Flashcards
(8 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.
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 pilus/pili?
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 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.
What is the structure of bacteria
- capsule for protection
- cell wall made of murein/peptidoglycan
- cell surface membrane controls what enters and leaves
- mesosome is site of respiration
- loop of DNA
- circular DNA called plasimd
- flagellum made of microtubules (part of cytoskeleton) to help move
- pili to attach onto a surface
Draw and name structures of a bacterial cell
Differemce between prokaryote and eukaryote
- prokaryote much smaller in size than eukaryote
- prokaryote has capsule present but absent in eukaryote
- prokaryotes has no membrane bound organelles
- prokaryote has mesosome as site of respiration but mitchondria is site of respiration for eukaryote
- prokaryote doesn’t have DNA in nucleus and no histone
- prokaryote has 70s ribosomes but eukrayote has 80s ribosomes
- prokaryote has circular DNA plasmid but eukaryote has linear DNA double helix
- prokaryote has cell wall made of murein/peptidoglycan but eukaryote has animal cell - no, plant - cellulose, fungi - chitin
