Bare Minimum Flashcards
diffusion affected by
1) Steepness/magnitude of diffusion/conc. Grad
2) Temperature
3) Mass/size of diffusing substance
4) Surface area
5) Diffusion distance
a. Cell size
b. Membrane thickness
Osmotic pressure
hydrostatic pressure (acting against) applied to a soln to prevent inward flow of water across semi-permeable membrane
Colligative property
depends only on number of solute not types/nature of particles in soln
Tonicity
measure of soln’s ability to change cell volume by altering water content
fluctuations in electrical current through ion channel due to…
conformational changes associated with gating
enzyme-like properties of transporter proteins
- Chemical specificity
- Inhibition; blocking of binding pocket
- Competition
- Saturation
primary active transport
E directly derived from hydrolysis of ATP
ATPase
transport proteins binding/hydrolysing ATP to provide enough E to cause conformational change and perform active transport
Pump-leak hypothesis
ions leak back into cell down grad so pump works continuously
importance of setting up conc grad
- Maintain RMP
- Electrical excitability
- Muscle contraction
- Maintain steady cell volume
- Nutrient uptake
- Maintain intracellular pH
secondary active transport
E stored in ionic conc grad established by primary
- Indirectly use energy from ATP hydrolysis
epithelial cells are separated by….
lateral intercellular and paracellular space
tight junctions hold…
epithelial cells at luminal edges
tight junction - barrier function
stop substance (e.g bacteria) movement through intercellular space (only some small ions, water etc. which varies by junction structure)
tight junction - fence function
prevent membrane protein from diffusing in plane of lipid bilayer => membrane domain formation:
- Apical/luminal/mucosal
- Basolateral
Higher electrical resistance =>
more tight junction strands holding together
proximal features
- leaky epithelium
- paracellular transport
- low electrical resistance
- low number of strands
- bulk transport
E.g duodenum, proximal tubule
Distal features
- tight epithelium
- transcellular transport
- high electrical resistance
- high number of strands
- hormonally controlled (less transport)
E.g colon, collect duct
paracellular transport
through tight junction
- diffusion + tightness
transcellular transport
through cell
- transporters + channels
transepithelial transport
- entry/exit steps
- Absorption: lumen (apical) -> blood
- Secretion: blood (basolateral) -> lumen - Electchem grad
- Forces driving passive / active movement - Electroneutrality
- Movement of cation / anion will attract counter ion - Osmosis
- Net ion movement => difference in osmolarity => water flow
inflammation
fighting against pathogens
antigens
antibody generator - molecules inducing immune response via lymphocytes
(many on pathogen surface)
Epitopes
small part of antigen recognised by antibodies/T cells
- 7 amino acids (may be linear or assembled by protein folding)
multiple antigens may share same epitope
immunogenicity
ability to provoke immune response by stimulating production of specific antibodies, proliferation of specific T cells (or B cells) or both
reactivity
ability to react specifically with the antibodies/cells it’s provoked
B cells
- develop and specialise in bone marrow
- transform into plasma cells => synthesis and secrete antibodies
- clone as well as save copy (memory B cells) for future infections
T cells
- develop in bone marrow
- mature in thymus
- several different types
contraction
activation of myosin’s cross bridges
hypertension
high blood pressure caused by narrowing/hardening of arteries => reduced flow => unwanted coagulation
multiple myeloma
form of leukemia where malignant B lymphocyte produces monoclonal Ig (single antibody)
- serum electrophoresis used to diagnose (immediately identified)
zymogens
inactive precursor of enzymes
zymogens and complement
complement are proteases that are inactive until cleaves (proteolytic cleavage activates)
lectin
carbohydrate binding proteins in blood that bind to unusual carbs found only on microbes
virulence factors
proteins produced by many microbes that inhibit the complement cascade
plasminogen
protease activated by tissue plasminogen activator (TPA) or streptokinase
threshold
certain voltage that the membrane potential must reach/exceed in order for action potentials to occur (~55 mV)
SA node
group of specialised cells in right atria that act more like nerves and don’t play much role in contraction
purkinje fibres
specialised conducting cells
muscle hypertrophy
increase and growth of muscle cells due to sustained use
muscle atrophy
progressive degeneration/shrinkage of muscle/nerve tissue due to reduction in activity caused by loss of innervation or lack of exercise
