Structure of Prokaryotic Cells

Question 1

Describe how prokaryotic cells differ from eukaryotic cells

Answer 1

-1. Prokaryotic cell cytoplasm contains no membrane bound organelles e.g. mitochondria WHEREAS eukaryotic cell contains membrane bound organelles
2. Prokaryotic cell has no nucleus / contains free floating DNA WHEREAS eukaryotic cell has a nucleus containing DNA
3. Prokaryotic DNA is circular and isn’t associated with proteins WHEREAS eukaryotic DNA is linear and is associated with proteins
4. Prokaryotic cell wall contains murein and peptidoglycan WHEREAS eukaryotic cell wall is made of cellulose
5. Prokaryotic cells have smaller 70s ribosomes WHEREAS eukaryotic cells have larger ribosomes
6. Prokaryotic cells may have…. one or more plasmid, a capsule, and/or one or more flagella

Question 2

Explain why viruses are considered as non-living

Answer 2

1. Acellular → not made of or able to be divided into cells
2. Non-living → unable to exist/reproduce without a host cell

Question 3

Attachment protein

Answer 3

Allows virus to attach to host cell

Question 4

Lipid envelope

Answer 4

Derived from host cell membrane

Question 5

DNA/RNA

Answer 5

Encodes virus proteins

Question 6

Capsid

Answer 6

Protein coat that encapsulates the DNA/RNA

Question 7

Nucleoproteins

Answer 7

Accessory proteins e.g. enzymes

Question 8

Virus replication

Answer 8

1. Virus attaches to host cell and injects genetic material
2. Genetic material used as code to synthesise proteins
3. New virus particles are assembled
4. Viruses burst out of, and destroy, host cell