Question

1. The three-dimensional shape of a protein determines its function. Briefly explain these terms as they relate to protein shape and provide a supporting example for each: denature, conformational change, genetic mutation. Each example must include a specific protein.

2. Compare and contrast simple diffusion and facilitated diffusion. In other words, how are they similar and how are they different? Provide supporting examples for each.

3. (a) What is the osmolarity of a solution containing 85 mM C6H12O6, 120 mM KCl, and 24 mM CaCl2? Show your calculations. (b) What would happen to human blood cells put in the solution above? Explain.

Answer 1

1) a) denaturation

It is a process in which tertiary, quaternary or secondary structure of the protein is destroyed to its primary structure by action of agents such as acids, heat etc.

Example- action of heat on egg during boiling.

b) conformational chamge- it is the change in the shape of the structure ( tertiary )of the protein to bring out certain actions.

Example- change in structure of protein during transportation pf ligands across the membrane.

Enzymes.

c) genetic mutation-

It is change in the sequence of amino acids either by deletion addition or translocation of amino acids whose sequence forms the proteins.

Example- sickle cell anemia, in which 6th amino acid that is glutamic acid is substituted by valine.

2) simple diffusion

It is downhill that is along the concentration gradient.

It is not carrier mediated.

No energy is required in simple diffusion.

It is a slower process.

Facilitated diffusion-

It is also downhill.

It is carrier mediated.

No energy is required during facilitated diffusion.

It is rapid than simple diffusion.

3) a) we know that multiplication of the molarity by the number of dissociation particles gives osmolarity.

Therefore,

Osmolarity= 1 × 85 ( glucose) + 2× 120 (KCl) + 3× 24 ( CaCl2)

= 85+ 240+ 72 = 397 mOsmol/L.

b) Osmolarity of plasma is 290 mOsmol/L.

And the osmolarity of the sbove solution is 397 mOsmol/L.

That means, solution ia hypertonic to the RBC, so they should shrink in the solution.