Biology: Carbohydrates

Carbohydrates

• General Characteristics:
  • Composed of carbon, hydrogen, and oxygen atoms
  • Typically have a 2:1 ratio of hydrogen to oxygen atoms
  • Can be simple or complex
• Types of Carbohydrates:
  1. Monosaccharides:
     • Simple sugars, e.g. glucose, fructose, galactose
     • Cannot be broken down into simpler sugars
  2. Disaccharides:
     • Composed of two monosaccharides, e.g. sucrose (glucose + fructose), lactose (glucose + galactose)
     • Can be broken down into simpler sugars
  3. Polysaccharides:
     • Composed of many monosaccharides, e.g. starch, cellulose, glycogen
     • Can be broken down into simpler sugars
• Functions:
  • Energy source for cells
  • Structural components (cellulose in plant cell walls)
  • Storage molecules (starch, glycogen)

Proteins

• General Characteristics:
  • Composed of amino acids
  • Amino acids linked by peptide bonds
  • Can be simple or complex
• Types of Proteins:
  1. Structural Proteins:
     • Provide structure and support for cells and tissues
     • Examples: collagen, keratin
  2. Enzymes:
     • Catalyze chemical reactions
     • Examples: lactase, peptidase
  3. Transport Proteins:
     • Transport molecules and ions across cell membranes
     • Examples: hemoglobin, albumin
  4. Defense Proteins:
     • Involved in immune response
     • Examples: antibodies, interferons
• Functions:
  • Structural components
  • Enzymatic activity
  • Transport and storage
  • Defense and immune response

Lipids

• General Characteristics:
  • Composed of carbon, hydrogen, and oxygen atoms
  • Typically have a high energy density
  • Can be simple or complex
• Types of Lipids:
  1. Fatty Acids:
     • Simple lipids, e.g. palmitic acid, oleic acid
     • Can be saturated or unsaturated
  2. Triglycerides:
     • Composed of three fatty acids and a glycerol molecule
     • Examples: fats, oils
  3. Phospholipids:
     • Composed of a glycerol molecule, two fatty acids, and a phosphate group
     • Examples: phosphatidylcholine, sphingomyelin
  4. Sterols:
     • Examples: cholesterol, ergosterol
• Functions:
  • Energy storage
  • Structural components (cell membranes)
  • Hormone regulation (steroids)
  • Insulation and protection (fats and oils)

Carbohydrates

• Composed of carbon, hydrogen, and oxygen atoms in a 2:1 ratio of hydrogen to oxygen atoms
• Can be simple (monosaccharides) or complex (disaccharides, polysaccharides)
• Examples of monosaccharides: glucose, fructose, galactose
• Disaccharides: composed of two monosaccharides, e.g. sucrose (glucose + fructose), lactose (glucose + galactose)
• Polysaccharides: composed of many monosaccharides, e.g. starch, cellulose, glycogen
• Functions: energy source for cells, structural components (cellulose in plant cell walls), storage molecules (starch, glycogen)

Proteins

• Composed of amino acids linked by peptide bonds
• Can be simple or complex
• Examples of structural proteins: collagen, keratin
• Enzymes: catalyze chemical reactions, e.g. lactase, peptidase
• Transport proteins: transport molecules and ions across cell membranes, e.g. hemoglobin, albumin
• Defense proteins: involved in immune response, e.g. antibodies, interferons
• Functions: structural components, enzymatic activity, transport and storage, defense and immune response

Lipids

• Composed of carbon, hydrogen, and oxygen atoms with high energy density
• Can be simple (fatty acids) or complex (triglycerides, phospholipids, sterols)
• Examples of fatty acids: palmitic acid, oleic acid (saturated or unsaturated)
• Triglycerides: composed of three fatty acids and a glycerol molecule, e.g. fats, oils
• Phospholipids: composed of a glycerol molecule, two fatty acids, and a phosphate group, e.g. phosphatidylcholine, sphingomyelin
• Sterols: e.g. cholesterol, ergosterol
• Functions: energy storage, structural components (cell membranes), hormone regulation (steroids), insulation and protection (fats and oils)