Biomolecules are the organic compounds that make up living organisms. They are essential for all cellular processes and functions. The four major types of biomolecules are carbohydrates, proteins, lipids, and nucleic acids.
Carbohydrates:
- Provide energy and structural support.
- Classified into monosaccharides, disaccharides, and polysaccharides.
- Examples: Glucose, fructose, sucrose, starch, cellulose.
Proteins:
- Perform diverse functions, including enzymes, hormones, transport, and structure.
- Made up of amino acids linked by peptide bonds.
- Examples: Enzymes like lipase and amylase, hormones like insulin and growth hormone, structural proteins like collagen and keratin.
Lipids:
- Store energy, provide insulation, and form cell membranes.
- Examples: Fats, oils, cholesterol.
Nucleic Acids:
- Store and transmit genetic information.
Key points:
- Biomolecules are essential for all life processes.
- The four major types of biomolecules are carbohydrates, proteins, lipids, and nucleic acids.
- Each type of biomolecule has unique functions and properties.
- The structure and composition of biomolecules determine their biological activities.
Exercise
1. What are macromolecules? Give examples.
Ans :
Macromolecules are large structures made up of numerous smaller molecules.. They are essential components of living organisms and play various roles in cellular processes.
Examples of macromolecules include:
- Nucleic acids: DNA and RNA are polymers of nucleotides, which consist of a sugar, a phosphate group, and a nitrogenous base. They store and transmit genetic information.
- Carbohydrates: Composed of monosaccharides (simple sugars) linked together. Carbohydrates provide energy, structural support, and cell recognition.
- Lipids: Hydrophobic molecules composed of fatty acids and glycerol. Lipids serve as energy storage, insulation, and components of cell membranes.
2. What is meant by tertiary structure of proteins?
Ans :
Tertiary structure refers to the three-dimensional shape of a protein molecule, formed by interactions between different amino acid side chains within the polypeptide chain. These interactions include:
- Hydrogen bonds: Weak attractions between polar amino acid side chains.
- Ionic bonds: Attractions between oppositely charged amino acid side chains.
- Disulfide bonds: Covalent bonds between cysteine amino acid residues.
- Hydrophobic interactions: Interactions between nonpolar amino acid side chains, which tend to cluster together away from water.
- Van der Waals forces: Weak attractive forces between atoms that are close together.
3. Find and write down structures of 10 interesting small molecular weight biomolecules. Find if there is any industry which manufactures the compounds by isolation. Find out who are the buyers.
Ans :
1. Glucose (C6H12O6): A simple sugar, the primary source of energy for cells.
2. Amino Acids: Building blocks of proteins, essential for various cellular functions.
3. Fatty Acids: Components of lipids, used for energy storage and cell membrane structure.
4. Nucleotides: Building blocks of DNA and RNA, consisting of a sugar, a phosphate group, and a nitrogenous base.
5. Steroids: Lipid-based molecules with various functions, including hormones and cell signaling.
6. Vitamins: Essential organic compounds required in small amounts for various metabolic processes.
7. Neurotransmitters: Chemical messengers in the nervous system, involved in communication between neurons.
8. Hormones: Chemical messengers that regulate various physiological processes in the body.
9. Antibiotics: Compounds produced by microorganisms that can inhibit the growth of other microorganisms.
10. Alkaloids: Nitrogen-containing compounds found in plants, often with medicinal properties.
4. Find out and make a list of proteins used as therapeutic agents. Find other applications of proteins (e.g., Cosmetics etc.)
Ans :
Proteins are essential biomolecules with diverse functions in the body. Many proteins are used as therapeutic agents to treat various diseases and conditions. Here are some examples:
- Insulin: Used to treat diabetes mellitus.
- Growth hormone: Used to treat growth hormone deficiency.
- Erythropoietin (EPO): Used to treat anemia.
- Factor VIII: Used to treat hemophilia A.
- Interferon: Used to treat certain viral infections and cancers.
- Antibodies: Used to target and neutralize specific antigens in the body, such as in immunotherapy for cancer treatment.
- Enzymes: Used as therapeutic agents to treat various enzyme deficiencies.
Other Applications of Proteins
Proteins have a wide range of applications beyond their use as therapeutic agents. Here are some examples:
- Cosmetics: Proteins are used in many cosmetic products, such as moisturizers, creams, and shampoos. They can provide hydration, improve skin texture, and enhance hair strength.
- Food industry: Proteins are essential components of food and are used as ingredients in various products, including meat, dairy, and plant-based alternatives.
- Industrial applications: Proteins are used in various industrial processes, such as detergents, biofuels, and textiles.
- Research and development: Proteins are used extensively in scientific research to study biological processes and develop new technologies.
5. Explain the composition of triglyceride
Ans :
Triglycerides are the most common type of lipid and are composed of three fatty acids esterified to a glycerol molecule.
- Glycerol: A triol (alcohol with three hydroxyl groups) that forms the backbone of the triglyceride molecule.
- Fatty Acids: Long chains of carbon atoms with a carboxylic acid group at one end. Fatty acids can be saturated (no double bonds between carbon atoms) or unsaturated (containing one or more double bonds).
6. Can you attempt building models of biomolecules using commercially available atomic models (Ball and Stick models).
Ans : Yes, it’s possible to build models of biomolecules using commercially available ball-and-stick models. These models are often used in educational settings to visualize the three-dimensional structure of molecules, including biomolecules like proteins, nucleic acids, and carbohydrates.
7. Draw the structure of the amino acid, alanine.
Ans :
8. What are gums made of? Is Fevicol different?
Ans :
Gums are natural polysaccharides derived from plants. They are made up of two or more different types of monosaccharides linked together through glycosidic bonds. Some common examples of gums include gum arabic, guar gum, xanthan gum, and tragacanth gum.
Fevicol, on the other hand, is a synthetic glue made of polyvinyl alcohol (PVA). It is not a polysaccharide and has different properties and uses compared to natural gums.
Gums are natural polysaccharides derived from plants, while Fevicol is a synthetic polymer-based adhesive.
9. Find out a qualitative test for proteins, fats and oils, amino acids and test any fruit juice, saliva, sweat and urine for them.
Ans :
Qualitative Tests for Biomolecules
Proteins:
- Biuret Test:
- Procedure: Add a few drops of dilute copper sulfate solution to the sample.
- Positive Result: A violet color indicates the presence of proteins.
Fats and Oils:
- Emulsion Test:
- Procedure: Add a few drops of the sample to a test tube containing water. Shake vigorously.
- Positive Result: If the sample forms a stable emulsion (cloudy appearance), it indicates the presence of fats or oils.
Amino Acids:
- Ninhydrin Test:
- Procedure: Add a few drops of ninhydrin reagent to the sample and heat it gently.
- Positive Result: A purple color indicates the presence of amino acids.
Testing Fruit Juice, Saliva, Sweat, and Urine:
- Fruit Juice: Most fruit juices contain carbohydrates and some may contain proteins. Test for carbohydrates using Benedict’s reagent (positive result: brick-red precipitate) and for proteins using the biuret test.
- Saliva: Saliva contains enzymes (proteins), so it will test positive for proteins using the biuret test. It also contains carbohydrates, so it will test positive for carbohydrates using Benedict’s reagent.
- Sweat: Sweat contains salts and water, but it may also contain traces of proteins and urea. Test for proteins using the biuret test and for urea using a urea test kit.
- Urine: Urine contains urea, a nitrogenous waste product. It can be tested for urea using a specific urea test kit. It may also contain traces of proteins and glucose, which can be tested using the biuret test and Benedict’s reagent, respectively.
10. Find out how much cellulose is made by all the plants in the biosphere and compare it with how much of paper is manufactured by man and hence what is the consumption of plant material by man annually. What a loss of vegetation!
Ans :
Cellulose Production and Consumption
Cellulose Production by Plants:
- Annual Production:
Approximately 100 billion tonnes of cellulose are produced by plants in the biosphere each year. - Dominant Biomolecule: Cellulose is the most abundant organic compound on Earth.
- Primary Component of Plant Cell Walls: Cellulose forms the structural framework of plant cell walls.
Paper Production:
- Annual Consumption: Global paper production consumes approximately 0.5 billion tonnes of wood annually.
- Wood Composition: Wood is primarily composed of cellulose, hemicellulose, and lignin.
- Paper Manufacturing Process: Cellulose is extracted from wood pulp and processed to produce paper.
Comparison and Loss of Vegetation:
While the amount of cellulose produced by plants is significantly higher than the amount used for paper production, the consumption of plant material for various human needs, including paper, timber, food, and other products, still contributes to a significant loss of vegetation. This loss of vegetation can have detrimental effects on ecosystems, biodiversity, and the environment.
11. Describe the important properties of enzymes.
Ans :
Specificity: Enzymes are highly specific for their substrates (the molecules they act upon).
Efficiency: Enzymes can significantly increase the rate of chemical reactions, often by millions of times. This allows for rapid and efficient biochemical processes.
Lower Activation Energy: Enzymes reduce the activation energy required for a reaction to occur, making it more likely to proceed.
Sensitivity to Environmental Conditions: Enzymes are sensitive to changes in temperature, pH, and other environmental factors. Optimal conditions are necessary for enzymes to function properly.
Regulation: Enzymes can be regulated to control the rate of biochemical reactions. This regulation can be achieved through various mechanisms, such as allosteric regulation, competitive inhibition, and noncompetitive inhibition.
Reversibility: Most enzymes can catalyze both the forward and reverse reactions of a chemical process. However, the direction of the reaction depends on the concentrations of reactants and products.
Protein Nature: Enzymes are primarily proteins, although some RNA molecules (ribozymes) can also act as catalysts.
