2: CELLS - PROKARYOTIC CELLS AND VIRUSES Flashcards
1
Q
What organelles are found in prokaryotic cells?
A
- cytoplasm
- plasmids
- single loop of DNA
- ribosomes
- cell membrane
- cell wall
- capsule
- flagellum
2
Q
What is the function of the capsule?
A
- secreted layer to protect against attacking immune cells
- allows cell to stick to surfaces
3
Q
What is the function of the flagellum?
A
helps cell move/swim faster
4
Q
What is the process of binary fission?
A
- circular DNA and plasmids replicate
- cell gets bigger and circular DNA strands move to opposite poles of cell
- cytoplasm begins to divide and new cell walls begin to form
- cytoplasm divides and 2 cells are produced (both have one copy of the circular strand of DNA but each can have a variable number of plasmids)
5
Q
What 4 components are viruses made of?
A
- core of genetic material (DNA/RNA)
- capsid (protein coat)
- attachment proteins
- envelope
6
Q
What is the function of the attachment proteins?
A
allow the virus to attach itself onto a suitable host cell
7
Q
How do viruses replicate?
A
- virus attaches itself to host cell receptor proteins
- genetic material is injected into host cell (coat of virus remains outside)
- genetic material and proteins replicated by host cell machinery (eg: enzymes, ribosomes)
- new protein coats synthesised within host cell
- viral components assemble
- replicated viruses released from host cell
8
Q
Why can some viruses only infect 1 type of cell?
A
attachment proteins are specific to the receptor proteins of a specific cell
