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

The Correct answer is To remove dirt and harmful microbes.

Key Points

• Fruits and vegetables often carry dirt, pesticides, and harmful microbes such as bacteria and viruses on their surfaces.
• Washing them helps in removing these contaminants, ensuring they are safe to consume.
• Harmful microbes like Escherichia coli (E. coli), Salmonella, and Listeria can cause foodborne illnesses if not removed before eating.
• Proper washing can also eliminate chemical residues from pesticides and fertilizers used during farming.
• Rinsing under running water is effective in dislodging dirt and microbes from the surface of fruits and vegetables.
• In some cases, using a vegetable brush can help clean tougher surfaces like potatoes or carrots.
• Washing fruits and vegetables is especially important if they are to be consumed raw, as cooking usually kills harmful microbes.

Additional Information

Vitamins can be divided into two categories:  

Fat-Soluble vitamins

• Fat-soluble vitamins are soluble in fats.
• They are absorbed by fat globules that travel through the small intestines and into the general blood circulation within the body.
• Unlike water-soluble vitamins, fat-soluble vitamins are stored in the body when they are not in use.
• Vitamin A, D, E K are fat-soluble.

Water-soluble vitamins

• Water-soluble vitamins dissolve in water, which means these vitamins and nutrients dissolve quickly in the body.
• Unlike fat-soluble vitamins, water-soluble vitamins are carried to the body’s tissues, but the body cannot store them.
• Any excess amounts of water-soluble vitamins simply pass through the body
• Vitamin B and Vitamin C are water-soluble.

The correct answer is Thiamin

Concept:

Vitamins are organic compounds required in the diet in small quantities to perform biological functions.

Classification of Vitamins:

• Fat-soluble vitamins: These are absorbed in dietary fats and stored in adipose tissues and the liver. These include vitamins A, D, E, and K.
• Water-soluble vitamins are dissolved in water and readily excreted by the kidneys, requiring regular supplements. These include vitamin C and B complex vitamins.

Explanation:

• Vitamin B1, also known as Thiamin, is a water-soluble vitamin that plays a critical role in energy metabolism and the functioning of the nervous system.
• It is involved in the conversion of carbohydrates into energy by acting as a coenzyme in the metabolism of glucose.
• The body cannot store thiamin in large amounts, so it needs to be consumed regularly through diet or supplements.
• Deficiency in thiamin can lead to conditions such as beriberi (affecting the cardiovascular and nervous systems) and Wernicke-Korsakoff syndrome (commonly seen in alcoholics).
• Good sources of Vitamin B1 include whole grains, legumes, nuts, seeds, and meat (especially pork).

Explanation of Other Options:

• Riboflavin: Riboflavin is Vitamin B2. It helps in energy production, maintains healthy skin and eyes, and supports the nervous system. It is also involved in the metabolism of fats, carbohydrates, and proteins.
• Retinol: Retinol is Vitamin A, which is crucial for vision, immune function, and skin health.
• Tocopherol: Tocopherol is Vitamin E. It acts as an antioxidant and helps protect cells from damage caused by free radicals. It also plays a role in immune function and skin health.

Additional Information 

CONCEPT:

Base Pairing in DNA

• DNA (Deoxyribonucleic Acid) is a double-stranded molecule, where the two strands are held together by base pairing between complementary nitrogenous bases.
• The four nitrogenous bases in DNA are:
  • Adenine (A)
  • Thymine (T)
  • Guanine (G)
  • Cytosine (C)
• The base pairing follows a specific rule known as Chargaff's Rule:
  • Adenine (A) pairs with Thymine (T) through two hydrogen bonds.
  • Guanine (G) pairs with Cytosine (C) through three hydrogen bonds.

EXPLANATION:

• Adenine pairs with Thymine - This is correct because adenine always pairs with thymine in a normal DNA molecule.
• Adenine pairs with Guanine - This is incorrect because adenine never pairs with guanine.
• Adenine pairs with Cytosine - This is incorrect because adenine never pairs with cytosine.
• Thymine pairs with Guanine - This is incorrect because thymine never pairs with guanine.

Based on the base pairing rules, the correct answer is: Adenine pairs with Thymine.

Therefore, the correct base pairing found in a normal DNA molecule is that Adenine pairs with Thymine.

The correct answer is Vitamin C.

Concept:

• Vitamins are organic substances that we need in sufficient quantities to maintain good health.
• Our body, however, cannot synthesize them. Therefore, we need to consume natural sources such as fruits and vegetables.
• Vitamins are divided into two groups– water-soluble vitamins (Vitamins of B group and Vitamin C) and fat-soluble vitamins (Vitamins A, D, E, and K).

Explanation:

• Vitamin C is the vitamin that is destroyed by heat during cooking.
• When we boil something that contains vitamin C, it reduces its content more than any other method of cooking.
• Broccoli, spinach, and lettuce, for example, lose up to or more than 50% of their vitamin C when they are cooked.
• Water-soluble vitamins are also temperature-sensitive vitamins.
• When the temperature drops below 86°F, vitamin C begins to denature.
• Vitamin C is primarily found in oranges, strawberries, tomatoes, broccoli, and green peppers, among other fruits and vegetables.
• When vitamin C is exposed to air, it is easily destroyed, which is what happens when food is overheated.
• When fat-soluble vitamins are heated or exposed to air, they are not destroyed.

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.

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.