Lecture 2 Flashcards
What is Na+ normal concentration in ECF?
135 - 145 mmol/L
What is Ca++ normal concentration in ECF?
2.1 - 2.6 mmol/L
What is K+ normal concentration in ECF?
3.5 - 5 mmol/L
What is the normal concentration of glucose in ECF?
fasting = 3.5 - 6 mmol/L
non fasting = 3.5 - 8 mmol/L
pH normal concentration of ECF?
7.35 - 7.45
Why is ECF composition important in multicellular organisms?
ECF must be maintained as it allows multicellular organisms to function in a diverse range of environments
What does osmolarity measure?
Measure of total number of solute particle per litre of solution
What is the normal osmolarity value in ECF & ICF?
275 - 300 mmosmol/L
What is tonicity?
The effect that a solution has on cell volume
Hypertonic solutions will cause cells to:
high pressure - SHRINK
Hypotonic solutions will cause cells to:
Low pressure - SWELL
What is the core body temperature value?
37 degrees
What is Simple Diffusion?
Passive transport
Diffusion of substances directly through the phospholipid bilayer from an area of high conc to an area of low conc
What are the different types of passive transport called?
Simple diffusion & Facilitated diffusion = Channels & Carrier
What do membrane channels do?
Channel structures in membrane allow specific substances to diffuse through the membrane. They open & close in response to stimuli, membrane potential etc
When is facilitated diffusion used?
When particles can’t directly pass through the phospholipid bilayer e.g charged ions and water soluble molecules
What is carrier mediated transport? How does it work?
Substances diffuse by means of carrier structures in membrane. Substance binds to carrier on one side of membrane, inducing carrier to change shape and release substance on other side
What are the different types of active transport called?
Transport pumps, endocytosis & excotysis
How do transport pumps work?
Pumps allow movement of particles from an area of low conc to an area of high conc by means of energy consuming pump structures in the membrane
What is endocytosis?
Substances are brought into the cell by trapping it in a section of the plasma membrane that pinches off to form a vesicle.
Phagocytosis = cell eating
Pinocytosis = cell drinking
What is exocytosis?
Substances leave cell by fusing a secretory vesicle with the membrane
What is Osmosis?
The net movement of water across its membrane down it own concentration gradient.
