Question 1: What is the primary function of DNA in living organisms?

Answer: DNA stores and transmits genetic information necessary for growth, development, and reproduction.

Question 2: Describe the basic structure of an amino acid and how they link to form proteins.

Answer: An amino acid has a central carbon atom bonded to an amino group, a carboxyl group, a hydrogen atom, and a side chain (R group). Amino acids link via peptide bonds to form proteins.

Question 3: Explain why DNA is considered a polymer and identify its monomers.

Answer: DNA is a polymer because it is made up of many nucleotide monomers linked together in a chain.

Question 1: Calculate the molecular weight of a single amino acid, glycine (C₂H₅NO₂). Use atomic weights: Carbon = 12 g/mol, Hydrogen = 1 g/mol, Nitrogen = 14 g/mol, Oxygen = 16 g/mol.

Answer: 75 g/mol

Question 2: If a solution contains 0.5 grams of amino acid in 100 mL of solution, what is its concentration in g/L?

Answer: 5 g/L

Question 1: What safety precautions should be taken when handling chemicals used in DNA extraction experiments?

Answer: Wear gloves, safety goggles, and lab coats; work in a well-ventilated area; avoid ingestion or inhalation of chemicals.

Question 2: Describe a simple method to extract DNA from a fruit sample, including the key steps.

Answer: Mash the fruit, add a solution of detergent and salt to break cell membranes and release DNA. Filter the mixture to remove solids, then add alcohol to precipitate the DNA, which appears as a stringy substance.

Question 1: A sample of DNA has a molecular weight of approximately 660 g/mol per nucleotide. If a DNA strand has 300 nucleotides, estimate the total molecular weight of the strand.

Answer: 198,000 g/mol

Question 2: In a protein sequence, there are 150 amino acids. Using an average amino acid molecular weight of 110 g/mol, estimate the total weight of the protein.

Answer: 16,500 g/mol

Question 1: Explain how the sequence of amino acids determines the structure and function of a protein. Include the roles of primary, secondary, and tertiary structures in your answer.

Answer: The sequence of amino acids (primary structure) determines how the protein folds into secondary structures like alpha helices and beta sheets. These structures further fold into a specific three-dimensional shape (tertiary structure) critical for the protein's function. The exact order of amino acids influences the shape and activity of the protein.

Question 1: Describe how DNA analysis is used in forensic science and the importance of amino acid sequencing in medicine.

Answer: DNA analysis helps identify individuals by comparing genetic profiles. Amino acid sequencing is crucial for understanding diseases, developing drugs, and designing personalized treatments.