Lecture 10 - Immune System part 1 Flashcards
Disease Definition
Impairs normal function of an organism can also be communicable / non-communicable
What causes disease ?
pathogens
viruses
bacteria
protists
fungi
Can be spread by air, water, touch
Virus/Bacteria grow in the body
Bacteria produces toxins that damage tissue making you feel ill
Viruses live and reproduce in cells causing damage
Primary defence Barriers
Eyes
Nose + Mouth
Skin
Stomach Acid
Trachea + Bronchi
Blood clotting
Globlet Cells
Mucous Membrane
Platelets
Structure of Bacteria
Ribosomes
Plasmids
Cell Surface Membrane
Cell Wall
Capsule
Circular DNA
Flagellum
Structure of Virus
Core of Genetic Material
Attachment Protein
Protein Capsid
Binary Fission
Replication of circular DNA and Plasmids
Division of Cytoplasm produces 2 daughter cells
Single copy of DNA and Variable number of plasmids in new
Antigens on blood types
Different blood types have different antigens on them or non at all
Example of blood types
Antibody A can only bind to Type A Antigen
Same with B
Type O has no antigen
B Lymphocyte Structure
Plasma Membrane
Nucleus
Cytoplasm
Antibody
Cytokines
Release at the site of infection
Act as a messenger
Opsonin
Attach to foreign Antigens to aid Phagocytosis
Phagocytosis - Neutrophil
Attracted to wound by cytokines
Receptors attach to opsonin
Cytoplasm moves around and engulfs pathogen
Phagosome is created
Lysosome binds to Phagosome
Lysozymes released
Phagocytosis
Pathogen engulfed
Phagosome Fuses with lysosome
Enzymes digest Pathogen
How to become a APC
GlyoProteins bind to antigen molecules
MHC-Antigen complex formed
Antigen moves to Cell surface membrane becoming an antigen presenting cell
Actually how becomes APC
Engulfed
Phagosome fuses with lysosomes
Pathogen destroyed by lysozymes
Antigen Displayed on Cell surface membrane
B Lymphocyte
Acts as Opsonin
Tags foreign bodies
Also sticks pathogens together (Agglutination)
Antibody
Are Glycoproteins
Made from polypeptides (amino acids)
Contains 4 chains - 2 heavy - 2 light
Held together by Disulphide Bridges
Also has Constant and Variable regions
Constant Region
Same for all Antibodies
Allows binding to phagocyte
Same Amino Acid sequence in all Antibodies
Variable Region
Each have a different shaped Variable Region due to amino acid structure
Complimentary to different Antigens
2 binding sites - binds to 2 antigens
Hinge region
Gives molecule Flexibility
Adjusts - distance between 2 sites vary
