Biomolecules MCQ Quiz - Objective Question with Answer for Biomolecules - Download Free PDF

The correct answer is Hypothalamus: Growth Hormone Synthesis.

Key Points

• The hypothalamus does not directly synthesize growth hormone; this is the function of the anterior pituitary gland (adenohypophysis).
• The hypothalamus regulates the secretion of growth hormone by producing Growth Hormone-Releasing Hormone (GHRH) and Somatostatin (growth hormone-inhibiting hormone).
• The anterior pituitary gland synthesizes and secretes growth hormone, which is critical for growth and metabolism.
• Other hypothalamic hormones include oxytocin and antidiuretic hormone (ADH), which are stored and released by the posterior pituitary gland.
• Thus, option 4 is incorrectly matched, as the hypothalamus is not directly responsible for growth hormone synthesis.

Additional Information

• Iodine and Thyroxine: Iodine is an essential micronutrient required for the synthesis of thyroxine (T4) and triiodothyronine (T3), hormones produced by the thyroid gland.
• Melatonin and Sleep Cycle: Melatonin is a hormone secreted by the pineal gland that regulates circadian rhythms, including the sleep-wake cycle.
• Insulin and Blood Sugar Regulation: Insulin, produced by the beta cells of the pancreas, is responsible for lowering blood glucose levels by facilitating the uptake of glucose into cells.
• Hypothalamus Functions: The hypothalamus is a key brain region that regulates body temperature, hunger, thirst, sleep, and the endocrine system through its control of the pituitary gland.
• Anterior Pituitary Gland: This gland synthesizes critical hormones such as growth hormone (GH), prolactin, thyroid-stimulating hormone (TSH), and adrenocorticotropic hormone (ACTH).

The correct answer is Uracil is energetically cheaper to synthesise.

Key Points

• Uracil is used in RNA instead of thymine because it is energetically cheaper to synthesize, making it more efficient for cells to produce RNA.
• Thymine contains an additional methyl group compared to uracil, which requires more energy for its synthesis.
• RNA molecules are generally short-lived compared to DNA, and the energy-efficient synthesis of uracil suits RNA's transient nature.
• In contrast, thymine is more stable and is used in DNA to protect it from degradation and mutations, ensuring long-term genetic storage.

Additional Information

• Uracil and Thymine:
  • Both uracil and thymine are pyrimidine bases, but thymine has an extra methyl group at the 5th carbon.
  • The structural difference affects stability, with thymine being more resistant to hydrolysis than uracil.
• Energetic Cost of Nucleotide Synthesis:
  • Synthesizing thymine involves additional enzymatic steps and energy compared to uracil.
  • This is why cells preferentially use uracil in RNA, where durability is less critical.
• RNA vs. DNA Stability:
  • RNA is a temporary molecule used in protein synthesis, making energy-efficient synthesis a priority.
  • DNA, as the hereditary material, requires higher stability, achieved partly by using thymine instead of uracil.
• Role of Uracil in RNA:
  • Uracil pairs with adenine during transcription, forming stable but transient hydrogen bonds.
  • Its presence is crucial for RNA's function in gene expression, including mRNA, tRNA, and rRNA.

The correct answer is fat-soluble vitamins.

Key Points

• Bile is essential for the emulsification of fats, which allows for the digestion and absorption of fat-soluble vitamins such as Vitamins A, D, E, and K.
• Without bile, fats remain undigested, and the absorption of fat-soluble vitamins in the small intestine becomes impaired.
• Fat-soluble vitamins require the presence of dietary fats and bile salts to form micelles, which facilitate their absorption into the intestinal cells.
• A deficiency in bile production can lead to health issues such as night blindness (Vitamin A deficiency), rickets (Vitamin D deficiency), and clotting disorders (Vitamin K deficiency).
• Patients with bile production issues may require medical interventions like bile supplements or dietary modifications to ensure proper nutrient absorption.

Additional Information

• Bile and Its Role:
  • Bile is produced by the liver and stored in the gallbladder, released into the small intestine during digestion.
  • It contains bile salts, cholesterol, and waste products like bilirubin, which help in fat digestion and the excretion of waste.
• Fat-Soluble Vitamins:
  • Fat-soluble vitamins include Vitamins A, D, E, and K, which are stored in the liver and fatty tissues for later use.
  • These vitamins are crucial for vision (A), bone health (D), antioxidation (E), and blood clotting (K).
• Micelle Formation:
  • Bile salts help in the formation of micelles, which are tiny droplets that make fats and fat-soluble vitamins soluble in the watery environment of the intestine.
  • This process is critical for their absorption across the intestinal lining.
• Diseases Linked to Bile Deficiency:
  • Conditions like gallstones, liver diseases, or bile duct obstructions can reduce bile production or flow, leading to malabsorption of fats and fat-soluble vitamins.
  • Patients may experience symptoms like diarrhea, weight loss, and deficiencies in fat-soluble vitamins.
• Treatment Options:
  • Treatment may include bile acid supplements, a low-fat diet, or addressing underlying conditions like gallbladder or liver disease.
  • Supplementation of fat-soluble vitamins is often recommended for individuals with chronic bile deficiency.

The correct answer is night blindness.

Key Points

• Night blindness, scientifically known as nyctalopia, is primarily caused by a deficiency of Vitamin A.
• Vitamin A is essential for the production of rhodopsin, a pigment in the retina that helps the eyes adapt to low-light conditions.
• This deficiency can lead to difficulty seeing in dim light or darkness, a hallmark symptom of night blindness.
• Vitamin A-rich foods such as carrots, spinach, sweet potatoes, and fish can help prevent night blindness.
• If untreated, severe Vitamin A deficiency may lead to more serious eye conditions, including xerophthalmia and corneal ulcers.

Additional Information

• Vitamin A: It is a fat-soluble vitamin essential for vision, immune function, reproduction, and cellular communication.
• Xerophthalmia: A severe form of Vitamin A deficiency that causes dryness of the conjunctiva and cornea, potentially leading to blindness.
• Rhodopsin: A light-sensitive protein found in the rod cells of the retina, crucial for vision in low-light conditions.
• Sources of Vitamin A: Rich dietary sources include liver, dairy products, eggs, and plant-based sources like carrots, sweet potatoes, and leafy greens.
• Global Concern: Vitamin A deficiency is a public health issue in many developing countries, particularly affecting children and pregnant women.

The correct answer is Carotene.

Key Points

• Carotene is a pigment responsible for the slight yellow color in cow's milk.
• It is a precursor to Vitamin A and is commonly found in plants, especially in carrots.
• The yellowish color of cow’s milk is mainly due to the presence of carotene from the cow’s diet.
• Carotene is fat-soluble, meaning it dissolves in the milk fat, causing the yellowish tinge.

Additional Information

• Xanthophyll: Xanthophylls are yellow pigments found in plants but are not directly responsible for the color of cow's milk. These pigments play a role in photosynthesis in plants.
• Riboflavin: Riboflavin (Vitamin B2) is a water-soluble vitamin found in milk. It contributes to the greenish hue in skimmed milk.
• Ribulose: Ribulose is a sugar involved in the Calvin cycle of photosynthesis. 

The Correct Answer is Option 1 i.e 8.

• B vitamins are a class of water-soluble vitamins.
• Vitamin B refers to several different types of vitamins that, together, are known as the B-complex vitamins.
• ​The commonly used Vitamin B Complex is constituted of 8 vitamins.
  • Thiamin (vitamin B-1)
  • Riboflavin (vitamin B-2)
  • Niacin (vitamin B-3)
  • Pantothenic acid (vitamin B-5)
  • Vitamin B-6
  • Biotin (vitamin B-7)
  • Folate (vitamin B-9)
  • Vitamin B-12

 Additional Information

Vitamin B Complex refers to a group of water-soluble vitamins that are essential for various metabolic processes in the body. The term "Vitamin B Complex" typically includes eight B vitamins:

Thiamine (Vitamin B1):

• Thiamine plays a key role in energy metabolism, particularly in the metabolism of carbohydrates.
• It is essential for the functioning of nerve cells and is involved in the synthesis of neurotransmitters.

Riboflavin (Vitamin B2):

• Riboflavin is involved in energy production, particularly in the electron transport chain of cellular respiration.
• It is essential for the metabolism of fats, carbohydrates, and proteins.
• Riboflavin is also important for maintaining healthy skin, eyes, and mucous membranes.

Niacin (Vitamin B3):

• Niacin is essential for energy metabolism, particularly in the form of nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP).
• It plays a role in DNA repair, cell signaling, and the functioning of the nervous system.
• Niacin is also used therapeutically to lower cholesterol levels.

Pantothenic Acid (Vitamin B5):

• Pantothenic acid is a component of coenzyme A (CoA), which is involved in numerous metabolic pathways, including the synthesis of fatty acids and the citric acid cycle.
• It plays a role in energy metabolism and the synthesis of hormones and neurotransmitters.

Pyridoxine (Vitamin B6):

• Pyridoxine is involved in amino acid metabolism, neurotransmitter synthesis, and the synthesis of heme (a component of hemoglobin).
• It is essential for the functioning of over 100 enzymes involved in various metabolic processes.

Biotin (Vitamin B7):

• Biotin is involved in the metabolism of carbohydrates, fats, and amino acids.
• It serves as a cofactor for enzymes involved in gluconeogenesis, fatty acid synthesis, and amino acid metabolism.

Folate (Vitamin B9):

• Folate is essential for DNA synthesis and cell division.
• It is particularly important during periods of rapid cell growth, such as during pregnancy and infancy.
• Folate deficiency can lead to neural tube defects in developing fetuses.

Cobalamin (Vitamin B12):

• Cobalamin is involved in DNA synthesis, red blood cell formation, and the functioning of the nervous system.
• It is required for the conversion of homocysteine to methionine and for the synthesis of myelin, a protective sheath around nerve fibers.

These eight B vitamins are commonly included together in Vitamin B Complex supplements because they work synergistically to support various aspects of health, including energy metabolism, nervous system function, and the synthesis of essential molecules in the body.

The correct answer is Vitamin D.

Key Points

• Vitamin D is a hormone produced by the kidneys.
• The liver and kidneys convert vitamin D into the active hormone, which is called calcitriol.
• It primarily helps in controlling the concentration of calcium in the blood.
• It is also vital for the development of strong bones.

Additional Information

The correct answer is Protein.

Key Points

• Wool and silk fibre are obtained from animals. 
• The protein fibre of silk is composed mainly of fibroin.
• The silk fibre is drawn from the cocoon of the silkworm.
• Wool is obtained from the fleece of sheep or goat.
• It is also obtained from the hair of rabbits, yak and camels. 
• So, silk fibre is primarily made up of protein.

The correct answer is delayed clotting of blood.

Key Points

• Vitamin K deficiency in our body leads to delayed clotting of blood.
• It plays a key role in helping the blood clot and preventing excessive bleeding.
• Unlike many other vitamins, vitamin K is not typically used as a dietary supplement.
• Vitamin K is actually a group of compounds.
• The most important of these compounds appears to be vitamin K1 and vitamin K2. Vitamin K1 is obtained from leafy greens and some other vegetables.
• Vitamin K2 is a group of compounds largely obtained from meats, cheeses, and eggs, and synthesized by bacteria.
• Low levels of vitamin K can raise the risk of uncontrolled bleeding.

Additional Information

The correct answer is one.

• A single chromosome contains only one DNA (deoxyribonucleic acid) molecule and so many genes.
• Humans have 23 pairs of chromosomes.
  • 22 pairs of autosomes chromosomes and one pair of sex chromosomes, X and Y.

Important Points

• In the cell nucleus, the DNA molecule is packaged into thread-like structures called chromosomes.
  • A chromosome (microscopic structure) is made up of DNA tightly coiled many times around proteins called histones that support its structure.
  • A chromosome has two arm - p arm (short arm) and q arm (long arm), joined in the location of the centromere.

Key Points

• The information in DNA (double helix structure) is stored as a code made up of four chemical bases: adenine (A), guanine (G), cytosine (C), and thymine (T).
  • DNA has two base pairs, A-T and G-C, attached to a sugar-phosphate backbone.

The correct answer is E.

Key Points

• Vitamin E is tocopherol.
• Vitamin E represents a group of compounds that contain both tocopherol and tocotrienol.
  • It is good for the immune system and it fights toxins.
  • It is a fat-soluble vitamin.
  • It is a very powerful antioxidant.
  • Weak muscles and fertility problems are signs of deficiency of vitamin E.
  • Its deficiency also causes hair damage and skin problems.

Important Points

The correct answer is Vitamin C.

Key Points

• Vitamins
  • Vitamins are chemical compounds that are required in small amounts for growth and good health and are obtained from our food.
  • The vitamins are not synthesized in the body that's why they must be supplied through the diet.
• ​Vitamin C
  • ​Vitamin C is a water-soluble compound found in living organisms. 
  • It is an essential nutrient for various metabolism in our body and also serves as a reagent for the preparation of many materials in the pharmaceutical and food industry.
  • Vitamin C also known as ascorbic acid is an essential nutrient in many multicellular organisms, especially in humans.
  • Ascorbic acid is a water-soluble vitamin and is found in variable quantities in citrus fruits, vegetables and organ meats.

Important Points

• Vitamins	Chemical Name	Deficiency Disease
  Vitamin A	Retinol	Night Blindness
  Vitamin B1	Thiamine	Beri-Beri
  Vitamin B2	Riboflavin	Angular Stomatitis
  Vitamin B3	Niacin	Pellagra
  Vitamin B5	Pantothenic Acid	Paresthesia
  Vitamin B6	Pyridoxine	Anemia
  Vitamin B7	Biotin	Dermatitis
  Vitamin B9	Folic Acid	Megaloblastic Anemia
  Vitamin B12	Methylcobalamin	Anemia
  Vitamin C	Ascorbic Acid	Scurvy
  Vitamin D	Cholecalciferol	Rickets
  Vitamin E	Tocopherols	Less Fertility
  Vitamin K	Menaquinones	Non-Clotting of Blood

The correct answer is Lipase.

Key Points

• Lipase enzymes are used in the stabilization of rice bran oil.
• Rice bran oil is known as wonder oil and it is the most important vegetable oil in Asia.
• Rice bran oil is extracted from bran which is the outer hard layer of rice.
• It is an emerging category in edible oil with a lot of nutritional properties and health benefits.
• Rice bran oil is heart-friendly, immunity, and prevents other diseases.
• The current study aimed to stabilize rice bran oil through different probiotic isolates and to assess the nutritional content of rice bran oil after stabilization.
• The study was aimed to inactivate naturally occurring lipases that can hydrolyze oil into glycerol and free fatty acid which is a serious problem that gives it a rancid taste and smell.

Additional Information

• Hydrolases are the group of enzymes that catalyze bond cleavages by reaction with water. The natural function of most hydrolases is digestion to break down nutrients into smaller units for digestion.
• Catalase is a key enzyme that uses hydrogen peroxide, a non-radical ROS, as its substrate. This enzyme is responsible for neutralization through the decomposition of hydrogen peroxide, thereby maintaining an optimum level of the molecule in the cell which is also essential for cellular signaling processes.
• Cellulase is any of several enzymes produced chiefly by fungi, bacteria, and protozoans that catalyze cellulolysis, the decomposition of cellulose and of some related polysaccharides. The name is also used for any naturally occurring mixture or complex of various such enzymes, that act serially or synergistically to decompose cellulosic material.

The correct answer is Glycogen

Key Points

• Glycogenesis:
  • The Biochemical process in which Glucose is converted into Glycogen in the liver is known as Glycogenesis.
  • The cell must have an excess of glucose for starting this process. Glucose is the starting molecule and is converted through the process of glycogenesis.
  • When the body does have readily available glucose, the body creates glycogen through the process of glycogenesis.
  • This process is activated during rest periods in the liver and also activated by insulin in response to high levels of glucose.
  • When the body gets an excess meal and the blood glucose levels are high, the pancreas releases insulin hormone to store glucose.
  • The fat in the human body is stored for long time energy but glycogen is not the same as fat.
  • When the blood glucose concentration has dropped, glycogen stores are often taken from meals. 

Important Points

• Glycogenolysis:
  • Glycogenolysis is the breakdown of the molecule glycogen into glucose.
  • Glycogenolysis occurs in muscle and liver cells when more energy needs to be produced. 
• Gluconeogenesis:
  •  Gluconeogenesis fulfil the needs for plasma glucose between meals.
  • Gluconeogenesis takes place in the liver and kidneys. Gluconeogenic substrates include glycerol, lactate, propionate, and certain amino acids. 
• Glycolysis:
  • Glycolysis is the metabolic process that breaks down glucose into pyruvic acid to produce energy.
  • This process occurs in the cytosol of the cell cytoplasm. Glycolysis is an oxygen-independent metabolic pathway. 

The correct answer is Option 2. 

Key Points

•  Vitamin B3, also known as niacin or nicotinic acid, is one of the eight B vitamins. It plays a crucial role in the proper functioning of the body and is involved in various metabolic processes.
• Here are some key points about vitamin B3:
  • Function: Niacin is essential for the conversion of carbohydrates, fats, and proteins into energy.
  • Sources: Niacin can be obtained from both animal and plant sources. 
  • Forms: Niacin exists in two forms: nicotinic acid and niacinamide (nicotinamide).
  • Deficiency: Severe niacin deficiency leads to a condition known as pellagra. 
  • Recommended Daily Intake: The recommended daily intake of niacin varies depending on age, sex, and life stage. 

Additional Information

• Vitamin B1, also known as thiamine, is one of the eight B-vitamins that play essential roles in maintaining the proper functioning of our bodies
• Vitamin B2, also known as riboflavin, is one of the water-soluble vitamins belonging to the B-complex group. It plays a crucial role in maintaining overall health and is involved in various metabolic processes in the body.