Tutorials of General Biochemistry /HND1 Exercise 1. Multiple Choices Questions (MCQs) 1- Glucose and fructose are examples of: a. Double sugar; b. Disaccharides; c. Single sugar; d. Polysaccharides. 2- What are described as “the building blocks of proteins”? a. Fiber; b. Lipids; c. Amino acid; d. Nutrients. 3- (CH2O)n is the molecular formula of which type of macromolecules? a. Proteins; b. Lipids; c. Carbohydrates; d. Nucleic acids. 4- Which macromolecules do not dissolve in water? a. Proteins; b. Lipids; c. Carbohdrates; d. Nucleic acids. 5- What are the monomers of lipids: a. Amino acids; b. Simple sugars; c. Fatty acid and glycerol; d. Nucleotides. 6- Oxidation of which substance in the body yields the most calories a. Glucose; b. Glycogen; c. Protein;; d. Lipids. 7- Milk is deficient in which vitamins? a. Vitamin C; b. Vitamin A; c. Vitamin B2; d. Vitamin K. 8- The degradative Processess are categorized under the heading of a. Anabolism; b. Catabolism; c. Metabolism; d. None of the above. 9- The digestive enzymes of cellular compounds are confined to: a. Lysosomes; b. Ribosomes; c. Peroxisomes; d. Polysomes. 10- The general formula of polysaccharides is a. (C6H10O5)n; b. (C6H12O5)n; c. (C6H10O6)n; d. (C6H10O6)n. 11- A polysacchharide which is often called animal starch is a. Glycogen; b. Starch; c. Inulin; d. Dextrin. 12- The constituent unit of inulin is a. Glucose; b. Fructose; c. Mannose; d. Galactose. 13- The polysaccharide found in the exoskeleton of invertebrates is a. Pectin; b. Chitin; c. Cellulose; d. Chondroitin sulphate. 14- Synthesis of Glucose from amino acids is termed as a. Glycolysis; b. Gluconeogenesis; c. Glycogenesis; d. Lipogenesis. 15- The absorption of glucose in the digestive tract a. Occurs in the small intestine; Instructor: DZOTAM KAMGUE Joachim, Ph.D Page 1 of 9 Tutorials of General Biochemistry /HND1 b. Is stimulated by the hormone Glucagon; c. Occurs more rapidly than the absorption of any other sugar; d. Is impaired in cases of diabetes mellitus. 16- The enzymes involved in Phosphorylation of glucose to glucose 6phosphate are a. Hexokinase; b. Glucokinase; c. Phosphofructokinase; d. Both (A) and (B). 17- An aromatic amino acid is a. Lysine; b. Tyrosine; c. Taurine; d. Arginine. 18- In proteins the α-helix and β-pleated sheet are examples of a. Primary structure; b. Secondary structure; c. Tertiary structure; d. Quaternary structure. 19- The enzyme trypsin is specific for peptide bonds of a. Basic amino acids; b. acidic amino acids; c. Aromatic amino acids; d. Next to small amino acid residues. 20- Chymotrypsin is specific for peptide bonds containing a. Uncharged amino acid residues; b. Acidic amino acids; c. Basic amino acid; d. Small amino acid residues. 21- Pepsinogen is converted to active pepsin by a. HCl; b. Bile salts c. Ca++; d. Enterokinase. 22- The optimal pH for the enzyme trypsin is a. 1.0–2.0; b. 2.0–4.0; c. 5.2–6.2; d. 5.8–6.2. 23- The optimal pH for the enzyme chymotrypsin is a. 2.0; b. 4.0; c. 6.0; d. 8.0. 24- Trypsinogen is converted to active trypsin by a. Enterokinase; b. Bile salts; c. HCl; d. Mg ++. 25- Kwashiorkor occurs when the diet is severely deficient in a. Iron; b. Calories; c. Proteins; d. Essential fatty acids. 26- Clinical features of Kwashiorkor include all of the following except a. Mental retardation; b. Muscle wasting; c. Oedema; d. Anaemia. 27- Kwashiorkor usually occurs in a. The post-weaning period; b. Pregnancy; c. Lactation; d. Old age. 28- Marasmus occurs from deficient intake of a. Essential amino acids; b. Essential fatty acids; c. Calories; d. Zinc. 29- Normal range of serum urea is a. 0.6–1.5 mg/dl; b. 9–11 mg/dl; c. 20–45 mg/dl; d. 60–100 mg/dl. Instructor: DZOTAM KAMGUE Joachim, Ph.D Page 2 of 9 Tutorials of General Biochemistry /HND1 30- Normal range of serum creatinine is a. 0.6–1.5 mg/dl; b. 9–11 mg/dl; c. 20–45 mg/dl; d. 60–100 mg/dl 31- Which among the following is a basic amino acid? a. Aspargine; b. Arginine; c. Proline; d. Alanine. 32- Zymogen is a. An intracellular enzyme; b. Serum enzyme; c. A complete extracellular enzyme; d. An inactivated enzyme. 33- International enzyme commission classifies enzymes into a. Three classes; b. Six classes; c. Four classes; d. Ten classes. 34- Vitamins are a. Accessory food factors; b. Generally synthesized in the body; c. Produced in endocrine glands; d. Proteins in nature. 35- A deficiency of vitamin B12 causes a. Beri-Beri; b. Scurvy; c. Perniciuos anemia; d. Ricket. 36- Consumption of raw eggs can cause deficiency of a. Biotin; b. Pantothenic acid; c. Riboflavin; d. Thiamin. 37- When eggs are cooked a. Biotin is destroyed but avidin remains unaffected; b. Avidin is inactivated but biotin remains unaffected; c. Both avidin and biotin are inactivated; d. Both avidin and biotin remain unaffected. 38- The most active form of Vitamin D is a. 25-Hydroxycholecalciferol; b. 1, 25-dihydroxycholecalciferol; c. 25-dihydroxyergocalciferol; d. None of these. 39- An example of ligases is a. Succinate thiokinase; b. Alanine racemase; c. Fumarase; d. Aldolase 40- An example of lyases is a. Glutamine synthetase; b. Fumarase; c. Cholinesterase; d. Amylase. 41- The pH optima of most of the enzymes is a. Between 2 and 4; b. Between 5 and 9; c. Between 8 and 12; d. Above 12 42- The degradative Processess are categorized under the heading of a. Anabolism; b. Catabolism; c. Metabolism; d. None of the above. 43- The exchange of material takes place a. Only by diffusion; b. Only by active transport; c. Only by pinocytosis; d. All of these. 44- The most active site of protein synthesis is the a. Nucleus; b. Ribosome; c. Mitochondrion; d. Cell sap. Instructor: DZOTAM KAMGUE Joachim, Ph.D Page 3 of 9 Tutorials of General Biochemistry /HND1 45- The fatty acids can be transported into and out of mitochondria through a. Active transport; b. Facilitated transfer; c. Non-facilitated transfer; d. None of these. 46- From the biological viewpoint, solutions can be grouped into a. Isotonic solution; b. Hypotonic solutions; c. Hypertonic solution; d. All of these. 47- Bulk transport across cell membrane is accomplished by a. Phagocytosis; b. Pinocytosis; c. Extrusion; d. All of these 48- The ability of the cell membrane to act as a selective barrier depends upon a. The lipid composition of the membrane; b. The pores which allows small molecules; c. The special mediated transport systems; d. All of these. 49- A lipid bilayer is permeable to a. Urea; b. Fructose; c. Glucose ; d. Potassium. 50- The Golgi complex a. Synthesizes proteins; b. Produces ATP; c. Provides a pathway for transporting chemicals; d. Forms glycoproteins. 51- The power house of the cell is a. Nucleus; b. Cell membrane; c. Mitochondria; d. Lysosomes. 52- The digestive enzymes of cellular compounds are confined to a. Lysosomes; b. Ribosomes; c. Peroxisomes; d. Polysomes. 53- Starch is a a. Polysaccharide b. Monosaccharide c. Disaccharide d. None of these 54- The most abundant carbohydrate found in nature is a. Starch; b. Glycogen; c. Cellulose; d. Chitin. 55- Obesity increases the risk of a. Hypertension; b. Diabetes mellitus; c. Cardiovascular disease; d. All of these. 56- Worldwide, the most common vitamin deficiency is that of a. Ascorbic acid; b. Folic acid; c. Vitamin A; d. Vitamin D. 57- Consumption of iodised salt is recommended for prevention of a. Hypertension; b. Hyperthyroidism; c. Endemic goiter; d. None of these. 58- Restriction of salt intake is generally recommended in a. Diabetes mellitus; b. Hypertension; c. Cirrhosis of liver; d. Peptic ulcer. 59- Polyuria can occur in a. Diabetes mellitus; b. Diarrhoea; c. Acute glomerulonephritis; d. High fever. 60- Vitamins are: a. Inorganic nutrients needed in small quantities in the body Instructor: DZOTAM KAMGUE Joachim, Ph.D Page 4 of 9 Tutorials of General Biochemistry /HND1 b. Organic substances needed in very large quantities in the body c. Any of various fat-soluble or watersoluble organic substances essential in minute amounts for normal growth and activity of the body and obtained naturally from plant and animal foods d. Products of endocrine gland secretion 61- Coenzymes are: a. Any of various fat-soluble or watersoluble organic substances essential in minute amounts for normal growth and activity of the body and obtained naturally from plant and animal foods b. Substances that prevent vitamins from exerting their typical metabolic effects c. Any of numerous proteins or conjugated proteins produced by living organisms and functioning as specialized catalysts for biochemical reactions d. Nonprotein organic substances that usually contain a vitamin or mineral and combines with a specific apoenzyme to form an active enzyme system 62- Select a fat-soluble vitamin: a. Ascorbic acid; b. Tocopherol; c. Thiamine; d. Riboflavin 63- Select a water-soluble vitamin: a. Vitamin A; b. Vitamin E ; c. Vitamin D; d. Vitamin B1. 64- Which of the following vitamins can be also synthesized from a dietary precursor? a. Vitamin С; b. Vitamin A; c. Vitamin B1 ; d. Vitamin B6; 65- Beri-beri is a. Disease caused by a deficiency of thiamine, endemic in eastern and southern Asia, and characterized by neurological symptoms, cardiovascular abnormalities, and edema. It is also called endemic neuritis b. Inflammation at the corners of the mouth caused by a deficiency of riboflavin, associated with a wrinkled or fissured epithelium that does not involve the mucosa c. A disorder of the lips often due to riboflavin deficiency and other B-complex vitamin deficiencies and characterized by fissures, especially in the corners of the mouth d. All of the above. 66- Dermatitis, diarrhoea and dementia are characteristics of: a. Dry beriberi; b. Pyridoxine deficiency; c. Scurvy; d. Pellagra. 67- Pellagra is: a. A disease caused by a deficiency of niacin in the diet and characterized by skin eruptions, digestive and nervous system disturbances, and eventual mental deterioration b. Inflammation of several nerves at one time caused by a deficiency of thiamin, marked by paralysis, pain, and muscle wasting. Also called multiple neuritis or polyneuritis; c. A severe form of anemia most often affecting elderly adults, caused by a failure of the stomach to absorb vitamin B12 and characterized by abnormally large red blood cells, gastrointestinal disturbances, and lesions of the spinal cord. Also called pernicious anemia, malignant anemia d. All of the above 68- Pernicious anemia is: a. A severe form of anemia most often affecting elderly adults, caused by a failure of the stomach to absorb vitamin B12 and characterized by abnormally Instructor: DZOTAM KAMGUE Joachim, Ph.D Page 5 of 9 Tutorials of General Biochemistry /HND1 large red blood cells, gastrointestinal disturbances, and lesions of the spinal cord; b. A form of anemia in which the capacity of the bone marrow to generate red blood cells is defective, caused by a bone marrow disease or exposure to toxic agents, such as radiation, chemicals, or drugs; c. Anemia characterized by a decrease in the concentration of corpuscular hemoglobin; d. All of the above 69- Rickets is: a. A deficiency disease resulting from a lack of vitamin D or calcium and from insufficient exposure to sunlight, characterized by defective bone growth and occurring chiefly in children b. A disease occurring primarily in adults that results from a deficiency in vitamin D or calcium and is characterized by a softening of the bones with accompanying pain and weakness c. A disease characterized by a decrease in bone mass and density, occurring especially in postmenopausal women, resulting in a predisposition to fractures and bone deformities such as a vertebral collapse d. All of the above 70- Scurvy is: a. A disease caused by deficiency of vitamin C and characterized by spongy bleeding gums, bleeding under the skin, and weakness b. Extreme dryness of the conjunctiva resulting from a disease localized in the eye or from systemic deficiency of vitamin A; c. A disease caused by deficiency of niacin in the diet and characterized by skin eruptions, digestive and nervous system disturbances, and eventual mental deterioration; d. All of the above; 71- Which of the following vitamins is given along with isoniazide in treatment of tuberculosis? a. Nicotinic acid; b. Riboflavin; c. Pyridoxine; d. Ascorbic acid. 72- Which of the following vitamins is also known as an antisterility factor? a. Vitamin E; b. Vitamin B6; c. Vitamin B1; d. Vitamin К. 73- Mega doses of which vitamin are sometime beneficial viral respiratory infections a. Vitamin С; b. Vitamin A; c. Vitamin К; d. Vitamin PP. 74- Which of the following vitamins improves megaloblast anemia but does not protect the neurological manifestations of pernicious anemia? a. Vitamin B12; b. Vitamin C; c. Vitamin PP; d. Vitamin D. Instructor: DZOTAM KAMGUE Joachim, Ph.D Page 6 of 9 Tutorials of General Biochemistry /HND1 Exercise 2. Opened -answer questions 1- Draw the structures of the following functional groups, pH 7.0: (a) Hydroxyl. (b) Carboxylate. (c) Amino. (d) Phosphoryl. 2- (a) On the reaction coordinate diagram shown below, label the transition state and the overall free-energy change ( ∆G) for the uncatalyzed reaction A → B. (b) Is this an exergonic (- ∆G) or endergonic (+ ∆G) reaction? (c) Draw a second curve showing the energetics of the reaction if it were enzyme-catalyzed. 3- You are given a solution containing an enzyme that converts B into A. Describe what you would do to determine the specific activity of this enzyme solution. 4- Match these molecules to their biological role 1- Carbohydrate storage in animal liver Proteoglycan 2- Extracellular matrix of animal tissues Starch 3- Blood clotting factor inhibitor Chitin 4- Carbohydrate storage in plants Cellulose 5- Polyanionic acid-sugar that forms main stalk of proteoglycans Glycogen 6- Structural component of plant cell walls Hyaluronic acid 7- Disaccharide Lactose 8- Exoskeleton of insects Heparin. 9- List five endocrine glands of your choice and for each, give: a. Its location in the body; b. Two hormones it secretes; and c. The role of each of these hormones. 10- What nutritional diseases can arise from a diet too rich in: a. Carbohydrates? b. Lipids (fats)? c. Proteins? Justify your answer each time. Instructor: DZOTAM KAMGUE Joachim, Ph.D Page 7 of 9 Tutorials of General Biochemistry /HND1 Exercise 2. Short answer questions 1- What are the techniques used in biochemistry to purify and/or identify compound of a biological mixture? For each technique, briefly describe the principle. 2- Draw a well labelled animal cell and indicate the function of six of its most important part (according to you). 3- Compare a eukaryotic and a prokaryotic cell. 4- What is the chemical composition of an animal cell membrane? 5- Define: metabolism, lipodosis, enzymes, isoenzyme, zymogenes, cofactor, and bioenergetics. 6- What is the general formula of the following molecules: a. Monosaccharide; b. Disaccharide; c. Polysaccharide; d. Glycerol; e. Fatty acid; f. Fat; g. Amino acid; h. Polypeptide. Exercise 3. Essay questions/ Write short notes on the following topics 123456- Factors that affect enzymes’ activity. Classification of vitamins. Procedure of plasma and serum preparation. Storage and structural polysaccharides. An overview on protein functions. Meaning of variation of blood glucose level. Exercise 4. Structural biochemistry You are given the following molecules: Instructor: DZOTAM KAMGUE Joachim, Ph.D Page 8 of 9 Tutorials of General Biochemistry /HND1 12345678- Classify them into: a) lipids; b) carbohydrate and c) protein monomers. Draw/give the general formula for: a) amino acids and b) monosaccharides. Draw the reaction that leads to the formation of sucrose by the two monosaccharides in the figure. Draw a dipeptide consist of two of the amino acids of your choices from the figure. Draw the structure of a diacylglycerol using precursors of fats in the figure. Give two function of cholesterol in the body. Give the name of three polymers consisting by glucose molecules. What are essential amino acids? How many are them in humans? Case study: In the hospital, it was learned that Mr. Percy Veere had lost 32 lb in the 8 months since his last visit to his family physician. On admission, his hemoglobin (the iron-containing compound in the blood, which carries O2 from the lungs to the tissues) was 10.7 g/dL (reference range, males = 12 - 15.5), his serum iron was 38 g/dL (reference range, males = 42 - 135), and other hematologic indices were also abnormal. These values are indicative of an iron deficiency anemia. His serum folic acid level was 0.9 ng/mL (reference range = 3 - 20), indicating a low intake of this vitamin. His vitamin B12 level was 190 pg/mL (reference range = 180 - 914). A low blood vitamin B12 level can be caused by decreased intake, absorption, or transport, but it takes a long time to develop. His serum albumin was 3.2 g/dL (reference range = 3.5 - 5.0), which is an indicator of protein malnutrition or liver disease. A dietary deficiency of calcium can lead to osteoporosis, a disease in which bones are insufficiently mineralized and consequently are fragile and easily fractured. Osteoporosis is a particularly common problem among elderly women. Deficiency of phosphorus results in bone loss along with weakness, anorexia, malaise, and pain. Iron deficiencies lead to anemia, a decrease in the concentration of hemoglobin in the blood. Question: Which foods would provide Percy Veere with good sources of folate and vitamin B12? Instructor: DZOTAM KAMGUE Joachim, Ph.D Page 9 of 9