Eukaryotic and Prokaryotic Cells, and Viruses Flashcards
What is a eukaryotic cell?
a cell that has it’s DNA contained in a nucleus and contains membrane bound organelles
What is a prokaryotic cell?
contains DNA that is ‘free’ in the cytoplasm and has no membrane bound organelles
Give an example of a eukaryotic cell
animal cells/plant cells/fungi cells
Give an example of a prokaryotic cell
bacteria cells
Where is the genetic material in a eukaryote?
chromosomes contained inside a nucleus, and are associated with proteins (histones)
Where is the genetic material in a prokaryote?
no true nucleus, only circular DNA and plasmids free in the cytoplasm
State the difference between the organelles within eukaryotes and prokaryotes
eukaryotes - have membrane bound, specialised organelles / prokaryotes - have no membrane bound organelles
State the difference in the ribosomes contained within the two types of cells
eukaryotes - 80s ribosomes / prokaryotes - 70s ribosomes
State the difference in the cell wall of the two types of cells
eukaryotes - cell wall mostly made of cellulose / prokaryotes - cell wall made of murein (peptidoglycan)
Name some structures found in prokaryotes
cell wall, flagellum, plasmids, capsule
Why can the capsule be a problem in bacteria?
because it prevents the detection of antigens on the surface of the bacteria, which means they are not detected by the body to allow an immune response to take place
How can plasmids be used in producing the insulin gene? (or any gene pretty much)
cut out the gene using enzymes, put the gene into the plasmid, then it reproduces and makes many copies of the insulin gene, then you separate them and filter it out
What is a virus?
an acellular, non living particle that is smaller than bacteria
Describe the structure of a virus?
genetic material enclosed within a protein coat called a capsid
What is a capsid and it’s function?
composed of protein subunits called capsomeres, and it’s function is to protect the viral genetic material from damage- can also assist the virus in infecting the host
Describe the capsid’s structure
has attachment proteins which help the virus recognise and bind to the cell in the host organism
What else can be surrounding some viruses?
some viruses such as HIV are surrounded by lipid envelopes as well which can have the attachment proteins if it is present
How do viruses reproduce? (Lytic cycle)
1- virus attaches to cell using their attachment proteins then penetrates it, injects it’s nucleic acid into the cell
2- viral nucleic acid replicates using the host cell machinery
3- new viral nucleic acids are packaged into viral particles and released from the cell, which could destroy the host cell in the process
How do prokaryotes divide?
through binary fission
