Biomolecules and Their Analysis

Biomolecules

• Biomolecules are essential organic compounds, crucial for life functions. They include carbohydrates, lipids, proteins, and nucleic acids.
• These molecules are composed of carbon, hydrogen, nitrogen, phosphorus, oxygen, and sulfur.
• Biomolecules play diverse roles in biological processes.

Analysis of Chemical Composition

• Analyzing organic compounds (proteins, nucleic acids, carbohydrates) involves treatment with trichloroacetic acid to break down organic matter for analysis.
• Analyzing inorganic compounds (minerals, metals) involves burning tissues to form ash.

Proteins

• Proteins are complex nitrogenous organic compounds made of amino acids.
• Approximately 22 different types of amino acids exist in nature.
• Amino acids are the building blocks of proteins, with each having an amino group, a hydrogen atom, a carboxyl group, and a unique side chain.
• Amino acids act as dipolar ions (zwitterions) in water.
• All amino acids, except glycine, exhibit optical activity due to a chiral carbon atom.

Formation of Peptide Bonds

• Amino acids combine to form peptides (dipeptides, tripeptides, and polypeptides).
• Polypeptides are long chains of amino acids.
• The first amino acid is N-terminal/amino-terminal and the last one is C-terminal/carboxyl-terminal.
• Peptide bonds link amino acids together.

Levels of Protein Organization

• Proteins have four levels of organization (primary, secondary, tertiary, and quaternary).
• Primary structure: Linear sequence of amino acids linked by peptide bonds.
• Secondary structure: Protein folds into alpha-helices or beta-sheets stabilized by hydrogen bonds.
• Tertiary structure: The three-dimensional arrangement of the entire protein molecule, stabilized by various forces such as hydrophobic interactions, hydrogen bonds, electrostatic interactions, van der Waals forces, and covalent bonds.
• Quaternary structure: Some proteins consist of multiple polypeptide chains interacting.
• Fibrous proteins: Insoluble in water, often structural (e.g., collagen).
• Globular proteins: Soluble in water, functional (e.g., enzymes, antibodies).

Nucleic Acids

• Nucleic acids are essential biomolecules (DNA and RNA).
• They consist of nucleotides (nitrogenous base + sugar + phosphate group).
• Two main types of nucleic acids: DNA (deoxyribonucleic acid) and RNA (ribonucleic acid).
  • DNA has deoxyribose sugar.
  • RNA has ribose sugar.
• Nucleotides consist of nitrogenous bases (purines and pyrimidines).
• Purines include adenine and guanine.
• Pyrimidines include thymine, cytosine, and uracil.
• DNA structure: Double-stranded helix; antiparallel strands; base pairing (A-T, G-C); hydrogen bonds stabilize the structure.
• Two types of DNA structure: B-DNA and Z-DNA.

RNA

• RNA is single-stranded and has various forms (mRNA, tRNA, rRNA) with specific functions in protein synthesis.

Carbohydrates

• Carbohydrates are organic compounds composed of carbon, hydrogen, and oxygen.
• Monosaccharides (simplest carbohydrates) include glucose, fructose, and galactose.
• Disaccharides are formed from two monosaccharides linked together, such as sucrose, lactose, and maltose.
• Polysaccharides (e.g., starch, glycogen, cellulose) are formed from long chains of monosaccharides.
• Starch and glycogen are energy storage forms found in plants and animals.
• Cellulose is a structural component in plant cell walls.

Lipids

• Lipids are hydrophobic molecules, insoluble in water but soluble in non-polar solvents like chloroform and benzene.
• Functions: Energy storage, structural component (cell membranes), protection in plants and animals.
• Fatty acids are building blocks of lipids with long hydrocarbon chains and a carboxyl group.
• Saturated fatty acids have no double bonds.
• Unsatruated fatty acids have one or more double bonds.
• Triglycerides are a crucial storage form of energy.

Enzymes

• Enzymes are proteins that catalyze (speed up) biochemical reactions in living organisms.
• Enzymes are not consumed in reactions.
• Enzyme activity is influenced by temperature, pH, and substrate concentration.
• Inhibitors can regulate enzyme activity.

This quiz explores the crucial role of biomolecules in life functions, focusing on carbohydrates, lipids, proteins, and nucleic acids. It also covers the analysis of chemical compositions of organic and inorganic compounds, emphasizing the significance of amino acids in protein structure. Test your knowledge on this fundamental topic in biochemistry!