Biomolecules: Carbohydrates Quiz

Carbohydrates

• Carbohydrates are organic macromolecules composed of carbon, hydrogen, and oxygen, with a general formula of CnH2non.
• They are soluble biomolecules and are important for life processes.
• Two major types: simple sugars (monosaccharides) and complex carbohydrates (polysaccharides).

Composition of Carbohydrates

• Monosaccharides are the building blocks, including glucose, galactose, and fructose.
• Disaccharides consist of two monosaccharides linked by glycosidic bonds, e.g., sucrose (glucose + fructose).
• Polysaccharides are long chains of monosaccharides, such as starch, glycogen, cellulose, and chitin.

Types of Polysaccharides

• Starch: A polymer of glucose found in plants, serves as an energy source.
• Glycogen: Storage form of glucose in liver and muscle cells; provides energy when needed.
• Cellulose: Major component of plant cell walls; known as fiber.
• Chitin: Constituent of exoskeletons in arthropods and cell walls of fungi.

Protein Structure and Types

• Proteins are formed from long chains of amino acids; there are 20 different amino acids.
• Amino acids consist of a central carbon, an amino group (-NH2), a carboxyl group (-COOH), a hydrogen atom, and a variable side chain (R).
• Four levels of protein structure: primary (amino acid sequence), secondary (alpha helix/beta sheets), tertiary (3D shape), and quaternary (multiple polypeptide chains).

Functions of Proteins

• Serve as enzymes, speeding up chemical reactions (e.g., salivary amylase).
• Provide structural support (e.g., collagen); involved in muscle contraction (e.g., myosin and actin).
• Perform protective functions (e.g., antibodies) and hormone production (e.g., insulin).

Lipids

• Lipids are large, nonpolar biomolecules, insoluble in water, often referred to as fats and oils.
• Major types include triglycerides (saturated and unsaturated fats), phospholipids, steroids, and waxes.
• Lipids provide a reserve source of energy and act as protective layers for organs.

Nucleic Acids

• Nucleotides are the building blocks of nucleic acids and consist of a pentose sugar, phosphate group, and nitrogenous base.
• DNA contains genetic instructions essential for life and organism functioning.
• RNA plays a role in converting genetic information from DNA into amino acid sequences for protein synthesis.

Summary of Biomolecule Functions

• Carbohydrates provide immediate energy and serve as energy reserves.
• Proteins are crucial for growth, repair, and as enzymes that facilitate biochemical reactions.
• Lipids are vital for long-term energy storage and cell membrane structure.
• Nucleic acids are necessary for encoding, transmitting, and expressing genetic information.