2.1.7 prokaryotic cells

Question 1

how are prokaryotic cells similar to eukaryotic cells

Answer 1

they have:
- plasma membrane
- cytoplasm
- ribosomes (assembling amino acids into proteins)
- DNA & RNA

Question 2

how are prokaryotic cells different to eukaryotic cells

Answer 2

• they’re much smaller
• have less well-developed cytoskeleton w/ no centrioles
• no nucleus
• don’t have membrane-bound organelles eg. mitochondria, chloroplasts
• wall made of peptidoglycan (not cellulose)
• smaller ribosomes
• naked DNA (loop) not wound around histone proteins

Question 3

what do some prokaryotic cells also have

Answer 3

• protective, waxy capsule surrounding cell wall
• small loops of DNA = plasmids
• flagella
• pili

Question 4

what are flagella

Answer 4

long whip-like projections enabling them to move
–> structure differs from eukaryotic undulipodia

Question 5

what are pili

Answer 5

smaller hair-like projections which:
- enable bacteria to adhere to host cells/each other
- allow passage pf plasmid DNA from 1 cell to another

Question 6

how do prokaryotic cells divide

Answer 6

binary fission

Question 7

what happens before they divide

Answer 7

their DNA is copied so each new cell receives large loop of DNA & any smaller plasmids