Biochemistry

Chemistry, SSC-Punjab Class 10. This chapter is split into 31 topics and has 673 practice questions. The topics covered are listed below, followed by 10 free sample questions from the chapter.

Topics in this chapter

1. Open chain structures of glucose and fructose 21 questions
2. Vitamin sources and deficiency diseases 22 questions
3. Gene therapy and cloning 23 questions
4. Peptide linkage and polypeptides 23 questions
5. Basics of healthy eating 21 questions
6. Calculations on carbohydrates 22 questions
7. Calculations on amino acids and peptides 21 questions
8. Classifying biomolecules 25 questions
9. Enzymes and exercise review 21 questions
10. Genetic engineering 20 questions
11. Soap and commercial products of fats and oils 20 questions
12. Calculations on fatty acids and fats 21 questions
13. Vitamins: nature and importance 23 questions
14. Blood tests 21 questions
15. Starch, cellulose and glycogen 23 questions
16. Biochemistry integrated review 21 questions
17. Carbohydrates: composition and classification 21 questions
18. Formation of fats from fatty acids and glycerol 24 questions
19. Sucrose, maltose and lactose 22 questions
20. Pregnancy test and HCG 20 questions
21. Glucose and fructose 23 questions
22. Denaturation of proteins 20 questions
23. Amino acids and glycine 22 questions
24. Nutrition and nutrients 21 questions
25. Proteins: composition and functions 24 questions
26. Daily intake of nutrients 20 questions
27. Cancer screening and genetic testing 21 questions
28. Nucleic acids: DNA and RNA 23 questions
29. Biochemistry and the three classes of food 21 questions
30. Lipids and fatty acids 23 questions
31. Functions of a healthy balanced diet 20 questions

Sample questions: Biochemistry

10 sample questions with the correct answer and an explanation. Try to answer each one before reading the explanation.

Q1. Which three classes of foods are named in the chapter as providing energy and body structure?

• A. carbohydrates, lipids (fats) and proteins(correct answer)
• B. salts, acids and bases
• C. metals, gases and liquids in food
• D. vitamins, minerals and water

Answer: A.Carbohydrates, lipids or fats and proteins are the three classes of foods that provide energy and are responsible for body structures.

Q2. A balanced diet rich in fruits, vegetables and grains can provide most of the:

• A. lipids needed for insulation
• B. energy that is used by the brain every day
• C. fats that the body needs as fuel
• D. vitamins and minerals needed daily(correct answer)

Answer: D.The book states a balanced diet rich in fruits, vegetables and grains can provide most of the vitamins and minerals needed daily.

Q3. Which of these is NOT listed as one of the four nutrient groups?

• A. vitamins and minerals
• B. carbohydrates
• C. lipids
• D. nucleic acids(correct answer)

Answer: D.Nucleic acids are biomolecules discussed later; the four nutrient groups in 25.1 are carbohydrates, lipids, proteins and vitamins/minerals.

Q4. A person eats only white rice for weeks. Which of the four nutrient groups is most likely to be deficient in the diet?

• A. energy, because rice gives none
• B. carbohydrates, because rice has none
• C. starch, because rice has none
• D. proteins and vitamins/minerals(correct answer)

Answer: D.Rice is mostly carbohydrate; a balanced diet needs proteins, lipids, vitamins and minerals too (application of the chapter's balanced-diet idea).

Q5. Why is it advised to reduce sugar intake?

• A. too much sugar contributes to disease and unhealthy weight(correct answer)
• B. sugar is not a carbohydrate at all
• C. sugar is a protein used to build muscles
• D. sugar is a mineral needed in huge amounts

Answer: A.The book lists sugar among items to be reduced; excess sugar leads to weight gain and diabetes (link to healthy diet's disease-prevention function).

Q6. Osteoporosis, mentioned in the book, is a disease of the:

• A. kidneys
• B. bones(correct answer)
• C. lungs
• D. eyes

Answer: B.Osteoporosis is a disease in which bones become weak and brittle (standard knowledge); the book lists it among diseases prevented by a balanced diet.

Q7. Carbohydrates are best described as:

• A. chains of nucleotides joined by phosphate bonds and sugars
• B. long chain fatty acids joined to glycerol
• C. polyhydroxy aldehydes or ketones and their derivatives(correct answer)
• D. chains of amino acids joined by peptide bonds

Answer: C.Having many -OH groups plus a carbonyl group (aldehyde or ketone) defines carbohydrates (standard summary of the book's description).

Q8. Exercise MCQ 3: Which function is NOT performed by proteins in our body?

• A. they serve as catalysts for biochemical reactions
• B. they serve as chemical messengers
• C. they carry oxygen in the blood
• D. they store genetic information(correct answer)

Answer: D.Genetic information is stored in nucleic acids (DNA), not in proteins; the other three are protein functions (hormones, enzymes, haemoglobin).

Q9. Why was goat fat boiled with wood ash extracts to make soap?

• A. wood ash supplies sugar that reacts with fat
• B. wood ash extracts contain an alkali that hydrolyses the fat(correct answer)
• C. goat fat is itself a strong mineral acid
• D. wood ash supplies protein that reacts with fat

Answer: B.Wood ash extracts contain potassium carbonate (an alkali), which hydrolyses fat to soap (standard explanation of the book's statement).

Q10. Nucleic acids are classified as:

• A. minerals found in the bones
• B. vitamins found in the foods
• C. biomolecules (natural polymers)(correct answer)
• D. gases found in the air

Answer: C.The learning outcomes list nucleic acids as main biomolecules; the book calls carbohydrates, proteins and nucleic acids natural polymers (chapter 26).