active cell physiology (lecture 7)

Question 1

what is osmosis

Answer 1

Osmosis relates to the water concentration and its travel across the semi permeable membrane to ensure for balanced isotonic solutions (balance tonicity)

Question 2

define isotonic, hypertonic and hypotonic

Answer 2

isotonic is the state of balance where water equals.
hypertonic (too much water in the cell) occurs when the ECF loses water and creates an imbalance, and
hypotonic (not enough water in cell) is the opposite of hypertonic where the ICF loses water and creates an imbalance

Question 3

an electrical gradient is caused when

Answer 3

uneven distribution of charged molecules across the membrane exists positive moving to negative

Question 4

what is known as the resting membrane potential

Answer 4

the negatively charged electrical gradient when the cell is at rest

Question 5

how is the excitable cell maintaining a negative gradient

Answer 5

the ATP active sodium potassium exchange pump works to bring ions each direction, bring 2K+ in the cell and pushing 3Na+ out of the cell against both of their concentration gradients. the electrical gradient therefore our excitable cell stays negative on the inside and positive on the outside and maintains the neg gradient

Question 6

define resting membrane potential

Answer 6

it is the point that the sodium potassium exchange pump is trying to get the cell to in order to be ready for the next excitable event, re-polarising the cell