Biological Macromolecules: Hydrolysis & Dehydration Synthesis

Biological Macromolecules

• Hydrolysis: breaks bonds in a polymer by adding water
• Dehydration Synthesis: bond forms between 2 monomers, and a water molecule is lost, facilitated by enzymes
• Dehydration Synthesis: "to put together while losing water", includes cholesterol, female and male sex hormones

Lipids

• Glycerol backbone with 3 fatty acid tails
• Dehydration Synthesis of Fats: 1 glycerol and 3 fatty acids attached by dehydration synthesis, forming triglycerides
• 3 water molecules are formed during dehydration synthesis
• Saturated Fats: contain no double bonds between carbons, solid at room temperature (e.g. butter, lard, shortening, bacon)
• Unsaturated Fats: have double bonds between carbons, liquid at room temperature (e.g. oils)

Proteins

• Made of carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur
• Composed of amino acids
• Functions: building blocks of living materials, compose structural parts, and enzymes
• Found in: meat, eggs, and cheese
• Structure: much larger and more complex than carbohydrates and lipids, containing carbon, hydrogen, oxygen, and nitrogen

Carbon Compounds

• 95% of all carbon compounds are organic
• Carbon atoms can form chemical bonds with other carbon atoms in long chains or rings
• Carbon compounds in living things: carbohydrates, lipids, nucleic acids, and proteins (macromolecules)

Polymers and Monomers

• Polymers: many individual small molecules (monomers) combining to form a larger molecule
• Monomers: individual small molecules that combine to form a polymer
• Examples:
  • Carbohydrates: polysaccharides, monosaccharides (simple sugars)
  • Lipids: fats, glycerol and fatty acids
  • Proteins: amino acids
  • Nucleic Acids: nucleotides

Dehydration Synthesis and Hydrolysis

• Dehydration Synthesis: process of joining monomers to form polymers, releasing water molecules
• Hydrolysis: chemical breakdown of polymers into monomers through the addition of water, opposite of dehydration synthesis

Carbohydrates

• Energy-rich compounds made from carbon, hydrogen, and oxygen
• Cells use carbohydrates to get and store energy
• Also called sugars or starches
• Plant cells store energy as starch

Proteins and Amino Acids

• Amino acids: building blocks of proteins, joined by peptide bonds (dehydration synthesis)
• 20 different amino acids, each with a unique R group
• Peptide bonds hold amino acids together, forming dipeptides, tripeptides, and polypeptides
• Denaturation: proteins lose their shape and function when exposed to extreme changes in pH, temperature, etc.

Nucleic Acids

• Compounds made of long, repeating chains called nucleotides
• DNA: a nucleic acid that contains the information cells need to make all of their proteins
• Function: important for growth and reproduction of cells, contains the genetic code
• Structure: sugar (deoxyribose or ribose), phosphate, nitrogen bases
• Building blocks: nucleotides