biochem

• What are the four main classes of biological molecules introduced in this lecture?

  Carbohydrates, lipids, nucleic acids, and proteins
• What is the significance of complex biological macromolecules being composed of smaller biomolecules?

  It highlights the hierarchical organization of biological structures and functions
• How can aldose and ketose sugars be distinguished?

  Aldose sugars contain an aldehyde group, while ketose sugars contain a ketone group
• What is the formation process of ring structures in monosaccharides?

  The carbonyl group reacts with a hydroxyl group in aqueous solution
• What is the molecular formula for monosaccharides?

  C$_n$H$_{2n}$O$_n$ where n = 3, 4, 5, or 6
• What functional groups are present in monosaccharides?

  Carbonyl and hydroxyl groups
• What are the characteristics of monosaccharides?

  They are hydrophilic, polar, and water-soluble
• What are the two types of monosaccharides based on their functional groups?

  Aldoses and ketoses
• What is the difference between D- and L-isomers of monosaccharides?

  1. isomers are the most naturally occurring forms, while L-isomers are not metabolized by cells
• What are epimers in the context of monosaccharides?

  Epimers are stereoisomers that differ in configuration at a single asymmetric carbon
• How do the α- and β-forms of glucose differ when in ring structure?

  They differ in the position of the hydroxyl group attached to carbon 1
• What type of bond forms between monosaccharides to create complex carbohydrates?

  Glycosidic bonds
• What is the linkage type for α-1→4 and β-1→4 in carbohydrates?

  They are types of glycosidic linkages
• What are disaccharides composed of?

  Two monosaccharides linked by a glycosidic bond
• What are polysaccharides and their function?

  Polysaccharides are polymers of glucose that act as energy stores
• What are the two forms of starch found in plants?

  Amylose and amylopectin
• How does glycogen differ from amylopectin?

  Glycogen has a similar structure to amylopectin but with more branches
• What is the role of sugars in cell surfaces?

  Sugars can form recognition molecules, such as blood group determinants
• What defines lipids in terms of solubility?

  Lipids are water-insoluble but soluble in organic solvents
• What are the monomeric building blocks of triacylglycerols and glycerophospholipids?

  Fatty acids
• How do the length and structure of fatty acids affect their properties?

  They determine the shape and melting point of the fatty acid
• What type of linkages form triacylglycerols?

  Ester linkages between fatty acids and glycerol
• Why are triacylglycerols important for cells?

  They are important energy storage molecules
• What is the structure of glycerophospholipids?

  They are based on glycerol with one fatty acid replaced by a phosphate group
• What is the significance of the amphipathic nature of glycerophospholipids?

  It allows them to form cell membranes by aggregating in aqueous environments
• What is the role of cholesterol in animal cell membranes?

  Cholesterol modulates membrane fluidity by inserting between glycerophospholipids
• What are the two types of nucleic acids?

  Ribonucleic acid (RNA) and deoxyribonucleic acid (DNA)
• What are the building blocks of RNA and DNA?

  Nucleotides
• What are the components of a nucleotide?

  A pentose sugar, a nitrogenous base, and a phosphate group
• What is the function of ATP in cells?

  ATP carries chemical energy in its phosphoanhydride bonds
• What roles do proteins play in the body?

  Proteins carry out mechanical, structural, and transport functions, and act as enzymes
• How does the structure of proteins relate to their function?

  The unique structure of each protein is determined by the DNA sequence of the gene
• How many amino acids are common to all living organisms?

  20 amino acids
• What is the significance of the side chains (R groups) of amino acids?

  They determine the properties of each amino acid and how proteins fold
• What type of bond links amino acids in polypeptides?

  Peptide bonds
• What is the basic structure of an amino acid?

  • Central carbon atom
  • Amino group (NH$_2$)
  • Carboxyl group (COOH)
  • Hydrogen atom
  • Side chain (R group)
• What is the significance of the polar nature of amino acids?

  • Determines solubility in water
  • Influences protein folding and function
  • Affects interactions with other molecules
• What are the main functions of nucleic acids?

  • Store and transmit genetic information
  • Serve as templates for protein synthesis
  • Carry chemical energy (e.g., ATP)
• What are the key features of carbohydrates?

  • Monosaccharides are the building blocks
  • Can form disaccharides and polysaccharides
  • Serve as energy sources and structural components