Biomolecules II Quiz

Macromolecules Overview

• Macromolecules consist of chains of smaller units called monomers, forming polymers.
• Dehydration synthesis refers to the process of monomers joining together, losing water in the process.
• Hydrolysis is the splitting of monomers using water, the reverse reaction of dehydration synthesis.

Nucleic Acids

• Nucleic acids, including DNA and RNA, are the most complex macromolecules.
• They store genetic information required for protein synthesis, cell growth, and replication.
• Monomers: Nucleotide; Polymers: Polynucleotide.
• Nucleotides consist of a phosphate group, sugar (different in DNA and RNA), and a nitrogenous base (A, T, C, G).
• The sugar-phosphate backbone supports nitrogenous bases which form the structure of DNA and RNA.

Nitrogenous Bases

• Nitrogenous bases include adenine (A), thymine (T), guanine (G), and cytosine (C).
• Base pairing rules: Adenine pairs with thymine (A-T), and guanine pairs with cytosine (G-C).
• C-G pairs are linked by three hydrogen bonds, while A-T pairs have two, highlighting differences in bonding strength.

Chargaff's Rules

• Chargaff discovered proportional relationships in nitrogenous bases: %A = %T and %C = %G.
• This established the concept that purines (A, G) equal pyrimidines (T, C) in DNA.

DNA Structure

• DNA is double-stranded with strands running in opposite (antiparallel) directions.
• Strands align such that nitrogenous bases pair through hydrogen bonds.

Proteins

• Proteins are macromolecules composed of amino acids, crucial for cellular structure and function.
• Monomer: Amino acid; Polymer: Polypeptide.
• Dehydration synthesis in proteins forms peptide bonds between amino acids.

Amino Acid Structure

• There are 20 different amino acids, each with distinct side chains (R groups) contributing to their function.
• The carboxyl group of amino acids transforms into a carbonyl group after dehydration synthesis.

Protein Structure Levels

• Proteins have four levels of structural organization:
  • Primary Structure: Sequence of amino acids in a polypeptide chain.
  • Secondary Structure: Folding of the polypeptide, forming alpha helices and beta-pleated sheets through hydrogen bonds.
  • Tertiary Structure: Interactions among helices and sheets lead to further folding of the polypeptide.
  • Quaternary Structure: Assembly of multiple polypeptides into a single functional protein.

Study Recommendations

• Review the structures and functions of nucleic acids and proteins.
• Familiarize with macromolecule synthesis and splitting processes.
• Consider the significance of amino acid properties in determining protein function.
• Understand the importance of hydrogen bonds in maintaining macromolecular structures.

Test your knowledge on Nucleic Acids, Proteins, and Macromolecules in this Biomolecules II quiz. This quiz will cover the structures and functions of essential biomolecules and their roles in biology. Prepare for your upcoming lecture exam with these crucial concepts!