Unit 1 Flashcards
Describe an immune response
Phagocyte engulf pathogens (recognises antigen)
Phagocyte activates T cells
T cells activate B cells which divide into plasma cells
Plasma cells make antibodies to specific antigen
How are antibodies used in pregnancy tests
Monoclonal antibody
Antibody for specific hormone in urine of pregnant women
Urine applied, hormone binds to antibody forming antigen-antibody complex
If hormone present, strip turns blue because blue beads attach when passing through
Name 4 functions of proteins
Enzymes
Antibodies
Transport proteins (hydrophilic head etc)
Structural proteins (long polypeptide chains parallel with cross links are physically strong)
How do enzymes work
Lower activation energy
Allows speed up Rate of reaction
What effects enzyme activity and how
Temperature
(Hot denature, cold not enough kinetic energy)
PH
(Acid or alkaline mess up ionic and hydrogen bonds, change tertiary structure, denature)
Substrate concentration (Higher faster until saturation point where more makes no difference)
Describe cell fractionation
Break up cell (homogenisation)
Get rid of big bits (filtration)
Separate organelles (ultracentrifugation)
How cholera work
Produce toxin Causes chloride channels open Chlorine moves into small intestine Lowers water potential Water osmosis into small intestine Leads to dihorreea
Describe breathing in
Diaphragm muscles contract
Rib cage moves up and out
Thorax volume increases
Pressure decreases
Causes air move in
Describe pulmonary tuberculosis
Immune system cells build wall around bacteria in lungs
This forms hard lumps called tubercles
Describe cardiac cycle
Ventricles relax, Atria contract
(Increases pressure in chamber, pushes blood into ventricles)
Ventricles contract, Atria relax
(Pressure in V higher than A, AV valves shut, SL valves open and blood forces into arteries)
Ventricles and atria relax
(Blood re-enters through pulmonary vein and vena cava, AV valves open)
How do pathogens cause disease
Produce toxins
Cell damage
Eg replicating inside cell causing it to burst
How do vaccines work
Contain antigen
Body produces memory cells against it
What are microvilli
Folds in plasma membrane
Increase surface area
Involved in absorption
How does the fluid mosaic model explain membrane properties
Controls what enters and leaves
Allows cell communication as contains receptor proteins
Barrier against most water-soluble molecules as hydrophobic tails make it hard for them to get through
Describe gas exchange in alveoli
O2 diffuses out alveoli and into blood
Co2 diffuses into alveoli from blood then is breathed out
