1. What are biomolecules and why are they important?
Answer: Biomolecules are organic molecules present in living organisms that are essential for life. They include carbohydrates, proteins, lipids, nucleic acids, and vitamins. They play critical roles in structure, function, and regulation of the body’s tissues and organs.
2. How are carbohydrates classified?
Answer: Carbohydrates are classified into monosaccharides, disaccharides, oligosaccharides, and polysaccharides based on the number of sugar units they contain.
3. What are aldoses and ketoses?
Answer: Aldoses are carbohydrates that contain an aldehyde group (-CHO), while ketoses contain a ketone group (C=O). Glucose is an example of an aldose, and fructose is an example of a ketose.
4. Define monosaccharides and give examples.
Answer: Monosaccharides are the simplest form of carbohydrates consisting of a single sugar unit. Examples include glucose and fructose.
5. What are the constituent monosaccharides of oligosaccharides like sucrose, lactose, and maltose?
Answer:
- Sucrose is composed of glucose and fructose.
- Lactose is composed of glucose and galactose.
- Maltose is composed of two glucose units.
6. What are amino acids and why are they important?
Answer: Amino acids are organic compounds that serve as the building blocks of proteins. They are important because they play key roles in processes such as protein synthesis, enzyme function, and cellular signaling.
7. What is a peptide bond?
Answer: A peptide bond is a covalent bond formed between the amino group of one amino acid and the carboxyl group of another amino acid, linking them together in a protein chain.
8. Define polypeptides and proteins.
Answer: Polypeptides are long chains of amino acids linked by peptide bonds. Proteins are complex molecules made up of one or more polypeptide chains that are folded into specific three-dimensional structures.
9. What is the primary structure of a protein?
Answer: The primary structure of a protein is its unique sequence of amino acids.
10. Describe the secondary structure of a protein.
Answer: The secondary structure refers to the local folding of the polypeptide chain into structures such as alpha-helices and beta-pleated sheets, stabilized by hydrogen bonds.
11. What is the tertiary structure of a protein?
Answer: The tertiary structure is the overall three-dimensional shape of a polypeptide, resulting from interactions between the side chains (R groups) of amino acids.
12. Explain the quaternary structure of a protein.
Answer: The quaternary structure is the arrangement and interaction of multiple polypeptide chains in a multi-subunit protein.
13. What is denaturation of proteins?
Answer: Denaturation is the process in which proteins lose their three-dimensional structure and biological function due to the disruption of non-covalent interactions, often caused by changes in temperature, pH, or exposure to chemicals.
14. What are enzymes and their role in biological processes?
Answer: Enzymes are biological catalysts that speed up chemical reactions in the body without being consumed. They are crucial for processes such as digestion, metabolism, and DNA replication.
15. How are vitamins classified?
Answer: Vitamins are classified into two categories: fat-soluble (vitamins A, D, E, and K) and water-soluble (vitamins B and C).
16. What are the functions of vitamins?
Answer: Vitamins play various roles, including acting as coenzymes, antioxidants, and hormones. They are essential for energy production, immune function, blood clotting, and other physiological processes.
17. What is the chemical constitution of DNA?
Answer: DNA is composed of nucleotides, each containing a phosphate group, a deoxyribose sugar, and one of four nitrogenous bases: adenine (A), thymine (T), cytosine (C), or guanine (G).
18. What is the chemical constitution of RNA?
Answer: RNA is composed of nucleotides, each containing a phosphate group, a ribose sugar, and one of four nitrogenous bases: adenine (A), uracil (U), cytosine (C), or guanine (G).
19. What are the biological functions of nucleic acids?
Answer: Nucleic acids store and transmit genetic information. DNA holds the genetic blueprint for the development, functioning, and reproduction of living organisms, while RNA plays a crucial role in protein synthesis and other cellular processes.
20. Provide a general introduction to hormones and their importance.
Answer: Hormones are chemical messengers produced by endocrine glands that regulate various physiological processes in the body. They are vital for growth, metabolism, reproduction, and maintaining homeostasis.