Question

1. Describe the molecular biology and biochemistry.

2. State the importance of studying the biological phenomena.

3. Distinguish between prokaryotes and eukaryotes.

4. List the similarities between prokaryotes and eukaryotes.

5. State the functions of the following cell components:

a) cytosol

b) mitochondria

c) chloroplast

d) vacoule

6. Explain about van der walls interaction. Give an example to support your explanation.

7. Why CH4 molecule is not capable for hydrogen bond?

8. Discuss the properties of water that make it a good solvent and buffer.

9. Describe about amphipathic.

10. What is chalatherate?

11. Explain how amphiphiles form micelles, membrane bilayers and vesicles.

12. Differentiate between ionization of water and water concentration.

13. Calculate the following molarity of solutions:

a) containing 72.9 grams of HCl in enough water to make 500 mL of solution?

b) containing 11.522 grams of KOH in enough water to make 350 mL of solution?

14. What is pH of 0.0002 M HI solution? What will be pH if 1 mL of the above was added to 999 mL of pure water?

15. What is pH of mixture prepared by mixing 20 mL 0.07 M NaOH and 13 mL 0.09 M HCl?

16. Calculate pH of 1 M solution of nitrous acid, pK_a=3.37.

17. Calculate pH of 0.001 M solution of benzoic acid, pK_a=4.19.

18. 0.1 M solution of weak acid has pH=4.0. Calculate pK_a.

19. 20 mL of 0.1 M solution of weak acid was mixed with 8 mL 0.1 M solution of NaOH. Measured pH was 5.12. Calculate pK_a.

20. Calculate the pH of a 0.2M solution of ammonia. K_a=5.62×10^-10.

21. Calculate pH of 0.01 M aniline hydrochloride. Aniline pK_b=9.4.

22. Calculate pH of 0.1 M potassium hydrogen oxalate. pK_a1=1.25, pK_a2=4.27.

23. Calculate pH of solution prepared from 0.1 mole of formic acid and 0.02 mole of NaOH diluted to 1L. pK_a=3.75.

24. You have 100 mL of 1 M ammonia solution (pK_a=9.25). What volume of 1 M hydrochloric acid is needed to prepare buffer with pH=9.5?

25. What will be pH of a 100 mL buffer solution containing 0.064 M of acetic acid and 0.036 M of sodium acetate, after addition of 1 millimole of the hydrochloric acid? pK_a=4.75.

26. Explain what happen to man who have an acidic blood fluid in his body.

Answer 1

1. Molecular biology: It is a branch of biochemistry which deals with the molecular basis of biological activity between biomolecules in the various systems of a cell, including the interactions between DNA, RNA, and proteins; and their biosynthesis, as well as the regulation of these interactions.

Biochemistry: It is also called biological chemistry and is the study of chemical processes within and relating to living organisms. Biochemistry is closely related to molecular biology. Depending on the exact definition of the terms used, molecular biology can be thought of as a branch of biochemistry, or biochemistry as a tool with which to investigate and study molecular biology.

2. The importance of studying biological phenomena lies in the structures, functions, and interactions of biological macromolecules, such as proteins, nucleic acids, carbohydrates, and lipids, which provide the structure of cells and perform many of the functions associated with life. The chemistry of the cell does also depend on the reactions of smaller molecules and ions. These smaller molecules can be inorganic (for example water and metal ions), or organic (for example amino acids, which are used to synthesize proteins).

3. Differences between prokaryotes and eukaryotes:

(i) Eukaryotes contain membrane-bound organelles including a nucleus, whereas prokaryotes do not contain a nucleus or other membrane-bound organelles.

(ii) Eukaryotic cells are bigger (~ 40 micrometers) in size, whereas prokaryotic cells are smaller(~ 5 micrometers) in size.

(iii) Eukaryotes are usually multicellular, whereas prokaryotes are unicellular.

(iv) Eukaryotic cells have mitochondria, whereas prokaryotic cells don't have mitochondria.

(v) Eukaryotic cells have more than one chromosome, whereas prokaryotic cells have one, which is not a true chromosome (it is a plasmid)

4. Similarities between prokaryotes and eukaryotes:

(i) They are composed of cells

(ii) They contain DNA as a heritable genetic material.

(iii) They transcribe DNA into RNA

(iv) They translate RNA into proteins on Ribosomes.

(v) They require chemical energy