Prokaryotic Cells And Viruses

Question 1

Describe what a virus is

Answer 1

-> accelular - not cells
-> nucleic acids - not even alive
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> invade and reproduce inside cells of organisms

Question 2

Differences between Prokaryotic and Eukaryotic cells

Answer 2

Prokaryotic cells:
-> no true nucleus,only and area where DNA is found
-> (Pro) DNA is not associated with proteins
-> some DNA may be in the form of circular strands called plasmids
-> no membeane-bounded organelles
-> no chloroplasts, only bacterial chlorophyll associated with the cell-surface membrane insome bacteria
-> ribosomes are smaller(70S)
-> cell wall made of murein
-> may have an outer mucilaginous layer called a capsule
Eukaryotic cells:
-> distinct nucleus, with a nuclear envelope
-> DNA is associated with proteins called histones
-> There are no plasmids and DNA is linear
-> membrane-bounded organelles, such as mitochondria , are present
-> chloroplasts present in plants and algae
-> ribosomes are large(80S)
-> where present, cell wall is made mostly of cellulose(chitin in fungi)
-> no capsule

Question 3

Functionality of different parts of a prokaryotic cell

Answer 3

-> Flagellum - moves the cell
-> Circular DNA (Chromosomal DNA)
-> Cytoplasm - chemical reactions occur, contains enzymes and ribosomes
->Ribosomes 70S - protein synthesis
-> Capsule - Secreted slime - helps protect from immune system
-> Cell Wall - made from murein (a glycoprotein)
-> Cell surface membrane - Control what goes in and out (made of lipids and proteins)
-> Plasmid DNA - loops of DNA

Question 4

Structure of a virus

Answer 4

-> NO CELL SURFACE MEMBRANE, CYTOPLASM, OR RIBOSOMES
-> Attachment protein - allows the virus to cling onto a suitable host cell
-> Capsid - A protective protein coat
-> Lipid envelope - “ONLY SOME VIRUS HAVE THIS”
-> has genetic material inside

Question 5

How do virus cell replicate?

Answer 5

-> inject their DNA or RNA into host cell (hijack cell) and uses the host cells organelle (ribosomes and enzymes to do the virus’ dirty work
->Virus must attach to host cell surface
- Use attachment proteins to bind to receptor proteins
- Receptor proteins are found on cell-surface membrane