Biochemistry: Carbohydrates and Nucleic Acids

Disaccharides

• Maltose is made from the dehydration reaction of two glucose monomers linked by a 1–4 glycosidic linkage
• Sucrose is made from the dehydration reaction of one glucose and one frutose monomers linked by a 1–2 glycosidic linkage

Storage Polysaccharides

• Starch is the major storage polysaccharide in plants and is made of entirely glucose monomers
• Starch is stored in granules within chloroplasts and other plastids
• Amylose is the simplest form of starch, it's unbranched
• Glycogen is the major storage polysaccharide in animals, such as humans, stored in liver and muscle cells

Structural Polysaccharides

• Cellulose is a major component of plant cell walls, its a polymer of glucose monomers linked by beta glycosidic linkages
• Different linkages impact the shape of the molecule, determining its function.

Nucleic Acids

• Nucleic acids are polymers called polynucleotides
• Each polynucleotide is made of monomers called nucleotides
• Each nucleotide consists of a nitrogenous base, a pentose sugar, and one or more phosphate groups
• The portion of a nucleotide without the phosphate group is called a nucleoside
• There are two families of nitrogenous bases:
  • Pyrimidines (cytosine, thymine, and uracil) have a single six-membered ring
  • Purines (adenine and guanine) have a six-membered ring fused to a five-membered ring
• In DNA, the sugar is deoxyribose; in RNA, the sugar is ribose

Protein Structure

• Proteins are biological functional macromolecules, made of one or more polypeptides
• Polypeptides are unbranched polymers built from the same set of 20 amino acids
• Amino acids are organic molecules with carboxyl and amino groups
• Amino acids differ in their properties due to differing side chains, called R groups
• There are different types of amino acids based on their side chains and properties:
  • Nonpolar, hydrophobic
  • Polar, hydrophilic
  • Electrically charged, hydrophilic
• Amino acids are linked by peptide bonds
• Each polypeptide has a unique linear sequence of amino acids, with a carboxyl end (C-terminus) and an amino end (N-terminus)

Fats (Lipids)

• Fats are lipids made of glycerol and fatty acids
• Fatty acids vary in length and the number and location of double bonds
• Saturated Fats:
  • Made from saturated fatty acids
  • Solid at room temperature
  • Mostly found in animal fats
• Unsaturated Fats:
  • Made from unsaturated fatty acids
  • Liquid at room temperature
  • Mostly found in plant fats and fish oils
• Hydrogenation:
  • Process of converting unsaturated fats to saturated fats by adding hydrogen
  • Can create trans fats, which are worse for cardiovascular health than saturated fats
• Essential fatty acids:
  • Some unsaturated fatty acids are not synthesized by the human body and must be supplied through diet
  • Include omega-3 fatty acids, which are important for growth and cardiovascular health

Phospholipids

• Phospholipids have two fatty acid tails attached to glycerol and a phosphate group
• The tails are hydrophobic, while the phosphate group and attachments form a hydrophilic head
• This structure makes them important components of cell membranes

Roles of Proteins

• Enzymes are proteins that act as catalysts to speed up chemical reactions
• Proteins are involved in multiple functions, including muscle tissue, connective tissue, and more.

This quiz covers essential concepts related to disaccharides, polysaccharides, and nucleic acids. Learn about the structures and functions of molecules like maltose, starch, and cellulose, as well as the significance of nucleotides in nucleic acids. Test your understanding of these fundamental biochemical components.