Define simple protein, conjugated protein and the globular protein

• Simple protein refers to protein that consists of only amino acids and does not contain any other substances. Example: collagen.
• Conjugated protein is a protein that contains non-protein materials called prosthetic groups. Example: haemoglobin.
• The globular protein is a polypeptide chain with tertiary or quaternary structures.  It is tightly coiled and folded into a spherical shape. Examples: enzymes, antibodies and some hormones. 

Amino acids are amphoteric molecules. Explain this statement.

• Amphoteric molecules can act both as a base and an acid.
• Amino acids have both acidic (carboxyl) and basic amino groups.
• At high concentrations of hydrogen ions, the negatively charged carboxyl group will accept protons and become uncharged and the overall charge of the amino acids becomes positive.
• At low concentration of hydrogen ions, the positively charged amino group loses its proton and the overall charge of molecule becomes negative. 

State factors that can cause the denaturation of proteins

• Heat or radiation
• Strong acids and alkalis
• High salt concentration and heavy metals
• Detergent and organic solvents
• Mechanical force           

Compare between fibrous protein and globular protein

Similarities: Both are polypeptides.

Differences:

Define hypertonic, hypotonic and isotonic solutions. State the movement of water in these solutions.

• A hypertonic solution is a solution that has more solutes and it had higher osmotic pressure than other solutions.
• A hypotonic solution is a solution that has fewer solutes and it had lower osmotic pressure than other solutions.
• An isotonic solution refers to a solution that has the same amount of solutes and therefore, the same osmotic pressure with another solution.
• Water tends to diffuse from hypotonic solution to hypertonic solutions and shows no net osmotic pressure movement from one isotonic to another isotonic solution. 

What is electrolysis?

Electrolysis is the production of a chemical reaction by passing an electric current through an electrolyte. In electrolysis, positive ions transfer to the cathode and negative ions to the anode. The reactions occurring depend on electron transfer at the electrodes and are therefore redox reactions. At the anode, negative ions in solution may lose electrons to form neutral species. Alternatively, atoms of the electrode can lose electrons and go into solution as positive ions. In either case the reaction is an oxidation. At the cathode, positive ions in solution can gain electrons to form neutral species. Thus cathode reactions are reductions.

What is electrolyte?

Electrolyte is a liquid that conducts electricity as a result of the presence of positive or negative ions. Electrolytes are molten ionic compounds or solutions containing ions, i.e. solutions of ionic salts or of compounds that ionize in solution. Liquid metals, in which the conduction is by free electrons, are not usually regarded as electrolytes. Solid conductors of ions, as in the sodium–sulphur cell, are also known as electrolytes.

e.g. acids, alkali, salts dissolved in water, molten salts