Question

B3. Cell Membrane and Cell Transport a) What kind of solution should a cell be placed in for it to become lysed? [1 mark] b) Give an example of a transmembrane protein. [1 mark] c) Which form of membrane transport does NOT require the expenditure of energy by the cell? [1 Mark] d) Given a cell with concentration of solutes in the environment lesser than the concentration of solutes in the surrounding fluid.. i. the extracellular fluid is said to be? [1 Mark] ii. the intracellular fluid is said to be? [1 Mark] e) Given the following molecules carbon dioxide, nitrogen, oxygen, potassium ion, water... i. Which is least likely to cross a cellular membrane by simple diffusion? [1 Mark] ii. Which will cross the membrane with the least speed? [1 Mark] iii. Which will cross the membrane with the fastest speed? [1 Mark] iv. Why is the molecule on iii able to cross faster than the molecule in ii? [1 Mark] 1) A bacterium containing sodium ions at a concentration of 0.1 mM lives in a pond that contains sodium ions at 0.005 mm. What specific mode of transport are the sodium ions entering the cell by? [1 Mark]

Answer 1

B3 Aus and Cell membrane Cell Transport A for it cell should be placed in a in a hypotonic solution to become lysed Because, hypotonic solection has lower solute concentration than cell. This water will from this solution to cell and swelling of cell and finally lysing bursting. cause its H₂OLL » Cell 9 Hypotonic solution H₂ona 7 Example of a Trans-membrane protein & Human Glycophorin G-protein linked receptor (GPCR) Receptor Tyrosine kinase (RTK), Bacterio rhodopsin Prominin Transmembrane as integral proteins because they run throughout the cell membrane etc. proteins also known

C > Passive transport does not require the expenditure of energy by the cell. Passive transport is notweally occurring phenom 10 menon and does not require energy. It invote movement of molecules down their concentration o gradient. d) Given that fluid inside the cell has lesser solute concentration and In surrounding fluid has higher solute concentration. solute] = 1 [solute] = Extracellular fluid Intracellular fluid i The extracellular fluid is ii) The intracellular fluid said to be Hypertonic said to be Hypotonic. Molecules nitrogen, oxygen, Carbon dioxide potassium ion , water... Cross can i) The molecule which cy least likely to cellular membrane by imple diffusion is potassium ion. There are impermeable to cross- Because charged particles be transported by proteins Water will the membrane with the least speed. Because it is small and polar , uncharged molecule. cross

Nitrogen will cross the membrane with the fastest speed. Because it is molecule gaseous and have low molecular weight. Q Nitrogen can cross faster due to gaseous nature and small molecular weight while water molecule speed plant because it is polar molecule . it will hot cross the hydrophobic portion of membrane easily. has least Thus, intracellular [Nat oilmy [Nat] in ponda 0.005 mm » [mat] a Oolmr [Nat] = 0.005 mm wat Nat. There ions concentration shows that concentration of sodium is higher inside the bacterial cell and lowen pond water. Thus, sodium lors will from pond water to bacterial cell concentraction gradient with the help of active transport. move against the