Bare Minimum

Question 1

diffusion affected by

Answer 1

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

Question 2

Osmotic pressure

Answer 2

hydrostatic pressure (acting against) applied to a soln to prevent inward flow of water across semi-permeable membrane

Question 3

Colligative property

Answer 3

depends only on number of solute not types/nature of particles in soln

Question 4

Tonicity

Answer 4

measure of soln’s ability to change cell volume by altering water content

Question 5

fluctuations in electrical current through ion channel due to…

Answer 5

conformational changes associated with gating

Question 6

enzyme-like properties of transporter proteins

Answer 6

• Chemical specificity
• Inhibition; blocking of binding pocket
• Competition
• Saturation

Question 7

primary active transport

Answer 7

E directly derived from hydrolysis of ATP

Question 8

ATPase

Answer 8

transport proteins binding/hydrolysing ATP to provide enough E to cause conformational change and perform active transport

Question 9

Pump-leak hypothesis

Answer 9

ions leak back into cell down grad so pump works continuously

Question 10

importance of setting up conc grad

Answer 10

• Maintain RMP
• Electrical excitability
• Muscle contraction
• Maintain steady cell volume
• Nutrient uptake
• Maintain intracellular pH

Question 11

secondary active transport

Answer 11

E stored in ionic conc grad established by primary

- Indirectly use energy from ATP hydrolysis

Question 12

epithelial cells are separated by….

Answer 12

lateral intercellular and paracellular space

Question 13

tight junctions hold…

Answer 13

epithelial cells at luminal edges

Question 14

tight junction - barrier function

Answer 14

stop substance (e.g bacteria) movement through intercellular space (only some small ions, water etc. which varies by junction structure)

Question 15

tight junction - fence function

Answer 15

prevent membrane protein from diffusing in plane of lipid bilayer => membrane domain formation:

• Apical/luminal/mucosal
• Basolateral

Question 16

Higher electrical resistance =>

Answer 16

more tight junction strands holding together

Question 17

proximal features

Answer 17

• leaky epithelium
• paracellular transport
• low electrical resistance
• low number of strands
• bulk transport
  E.g duodenum, proximal tubule

Question 18

Distal features

Answer 18

• tight epithelium
• transcellular transport
• high electrical resistance
• high number of strands
• hormonally controlled (less transport)
  E.g colon, collect duct

Question 19

paracellular transport

Answer 19

through tight junction

- diffusion + tightness

Question 20

transcellular transport

Answer 20

through cell

- transporters + channels

Question 21

transepithelial transport

Answer 21

1. entry/exit steps
   - Absorption: lumen (apical) -> blood
   - Secretion: blood (basolateral) -> lumen
2. Electchem grad
   - Forces driving passive / active movement
3. Electroneutrality
   - Movement of cation / anion will attract counter ion
4. Osmosis
   - Net ion movement => difference in osmolarity => water flow

Question 22

inflammation

Answer 22

fighting against pathogens

Question 23

antigens

Answer 23

antibody generator - molecules inducing immune response via lymphocytes
(many on pathogen surface)

Question 24

Epitopes

Answer 24

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

Question 25

immunogenicity

Answer 25

ability to provoke immune response by stimulating production of specific antibodies, proliferation of specific T cells (or B cells) or both

Question 26

reactivity

Answer 26

ability to react specifically with the antibodies/cells it’s provoked

Question 27

B cells

Answer 27

• 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

Question 28

T cells

Answer 28

• develop in bone marrow
• mature in thymus
• several different types

Question 29

contraction

Answer 29

activation of myosin’s cross bridges

Question 30

hypertension

Answer 30

high blood pressure caused by narrowing/hardening of arteries => reduced flow => unwanted coagulation

Question 31

multiple myeloma

Answer 31

form of leukemia where malignant B lymphocyte produces monoclonal Ig (single antibody)
- serum electrophoresis used to diagnose (immediately identified)

Question 32

zymogens

Answer 32

inactive precursor of enzymes

Question 33

zymogens and complement

Answer 33

complement are proteases that are inactive until cleaves (proteolytic cleavage activates)

Question 34

lectin

Answer 34

carbohydrate binding proteins in blood that bind to unusual carbs found only on microbes

Question 35

virulence factors

Answer 35

proteins produced by many microbes that inhibit the complement cascade

Question 36

plasminogen

Answer 36

protease activated by tissue plasminogen activator (TPA) or streptokinase

Question 37

threshold

Answer 37

certain voltage that the membrane potential must reach/exceed in order for action potentials to occur (~55 mV)

Question 38

SA node

Answer 38

group of specialised cells in right atria that act more like nerves and don’t play much role in contraction

Question 39

purkinje fibres

Answer 39

specialised conducting cells

Question 40

muscle hypertrophy

Answer 40

increase and growth of muscle cells due to sustained use

Question 41

muscle atrophy

Answer 41

progressive degeneration/shrinkage of muscle/nerve tissue due to reduction in activity caused by loss of innervation or lack of exercise