Immunology COPY Flashcards
Define Pathogen
A disease-causing agent
State three factors that make something cellular
Made of cells
Able to reproduce independently of a host
Able to undertake independent metabolic processes
State three types of cellular pathogen
Bacteria
Fungi
Parasites
By what process do bacteria divide?
Binary fission
State how bacterial pathogens cause disease
Bacteria release toxins.
Bacterial populations are high due to rapid reproduction by binary fission.
This increases the volume of toxin produced, which causes illness.
State how a virus causes disease
When a virus invades a host cell it damages or destroys the cell, causing disease
Explain how a virus replicates itself
The virus is engulfed into a host cell and inserts its genetic material into host cell’s DNA.
The virus uses host cell organelles to produce new protein coats (at the ribosome) and replicate genetic material.
State how fungal pathogens cause disease
Fungi cause disease by releasing enzymes which break down proteins
Define antigen
An antigen is a unique molecule or part of a molecule that initiates an immune response
State two types of non-cellular pathogen
Virus
Prion
State three types of barriers against disease
Physical
Chemical
Microbiological/Microbial
State an example of a physical barrier against disease
Intact skin, Hair, Earwax
State an example of a chemical barrier against disease
Saliva, tears, stomach acid, mucous, sweat
Describe how microbial barriers can prevent disease
non-pathogenic bacteria outcompete pathogenic bacteria for space and nutrients, preventing colonies being established in the human body
How do lysozymes in tears and saliva act as a barrier against disease?
Lysozymes are enzymes that break bacterial cell walls, so bacterial cells burst due to osmosis