A-Level Chemistry Question Analysis Topic: Chemistry - Short Questions
Exam Questions:
1) What is the reason for the stability of colloidal sols?
2) (i) Write the structural difference between starch and cellulose?
(ii) What type of linkage is present in nucleic acids?
(iii) Give one example each for fibrous protein and globular protein?
Answers:
For A-Level Chemistry, you should know:
1) The colloidal particles in a given colloid all carry the same charge, which can be either positive or negative. Colloidal particles with similar charges repel one another. This keeps them from getting closer to one another and forming bigger particles. This provides the stability of the colloidal solution i.e., by preventing it from coagulating.
2) (i) In contrast to starch, which can be found in both linear and branched chains, cellulose is mostly linear chains of glucose molecules linked by beta 1,4 glycosidic bonds.
Starch has alpha 1,4 linkages while cellulose has beta 1,4 linkages between the glucose units.
(ii) When nucleotides combine through phosphodiester linkages between the 5' and 3' carbon atoms, nucleic acids are formed. The order of nucleotides in DNA is known as a nucleic acid sequence.
(iii) Examples of fibrous proteins: keratin and spectrin
Examples of globular proteins: albumin and haemoglobin
Work hard for your A-Level Chemistry examination!
End of analysis. Great!
