Topic 2a- Prokaryotic Cells and Viruses

Question 1

What is a prokaryotic bacterial cell structure?

Answer 1

It contains a cell wall (made of murein, a peptidoglycan), cell membrane, capsule for protection, cytoplasm contains enzymes, ribosomes, food granules. flagella for movement, genetic material.
There is no ER, golgi or mitochondria.
They have rings of DNA called plasmids, able to move from one bacterial cell to another.

Question 2

What are viruses?

Answer 2

Viruses are acellular (they’re not cells).
They are nucleic acids surrounded by protein.
Viruses contain a core of genetic material- either DNA or RNA.
The protein coat around the core is called the capsid.
Attachment proteins stick out from the edge of the capsid. Let the virus cling on to a suitable host cell.

Question 3

What is a mesosome?

Answer 3

Site of respiration, bacterial cells do not have mitochondria.
A mesosome is an infolding of the cell surface membrane which is involved in aerobic respiration.
Photosynthesising bacteria have a special form of chlorophyll but no chloroplasts.

Question 4

Prokaryotic cells replicate by binary fission. What is binary fission?

Answer 4

In binary fission, the cell replicates it’s genetic material, before physically splitting into two daughter cells.