The Structure and Function of Macromolecules Chapter 5 The Structure and Function of Macromolecules

Introductory Terms Macromolecule = “giant” molecule of living matter Monomer = subunits that serve as the building blocks of a polymer Example: Lego block Polymer = monomers linked together Example: Lego castle

Macromolecular Reactions  Dehydration Synthesis: 2 molecules become covalently bonded to each other through the loss of water Hydrolysis: Water is used to break up polymers to monomers

Macromolecular Diversity Diversity in polymers is due to differing arrangements of monomers… Nearly infinite possibilities… Alphabet analogy

Carbohydrates Structure: Functions: C:H:O in a 1:2:1 Ratio Example: C6H12O6 Functions: Short-term energy storage Pasta dinner before the big race, game, etc. Structural Support

Carbohydrates Monosaccharides: “one sugar” C:H:O Ratio = 1:2:1 Glucose (C6H12O6) is a monosaccharide

Carbohydrates Disaccharides: “double sugar” 2 monosaccharides joined together by a glycosidic linkage (covalent bond) Sucrose = glucose + fructose

Carbohydrates Polysaccharides Polymers in which a few hundred to a few thousand monosaccharides are linked together Starch and glycogen are examples

Carbohydrates Structural Polysaccharides Cellulose Chitin Major component of plant cell walls Cannot be digested by humans Fiber! Chitin Used by arthropods to build exoskeletons Cell wall of fungi

Lipids Structure: Functions: Made up of carbon, hydrogen, oxygen Do not dissolve in water Functions: Long-term energy storage Chemical messengers (hormones) Insulation Waxes

Lipids Fats Made of glycerol and 3 fatty acids Fatty acid has a long carbon skeleton and a carboxyl group C-H bonds responsible for hydrophobia of fats

Lipids Fats Saturated Fat = no double bonds Saturated with hydrogen Unsaturated Fat = double bonds Not saturated with hydrogen

Lipids Phospholipids Have only 2 fatty acids Instead of 3rd fatty acid, they have a phosphate group Major component of cell membrane

Lipids Steroids Made up of 4 interconnected rings Examples: Cholesterol Testosterone Estrogen

Proteins *** Most of a cell is made up of proteins Instrumental in almost everything organisms do Structure: All proteins are created from unique combinations of 20 different amino acids C,H,O,N Major Functions: Structure Defense (antibodies) Enzymes

Proteins Amino Acids Amino acids are the monomers of proteins Organic molecules possessing both carboxyl and amino groups 20 types of AAs that make up 1000s of different proteins AAs are linked together by peptide bonds

Amino Acids

Proteins A protein is one or more polypeptides precisely twisted, folded and coiled into a molecule of unique shape (3-D) 4 Levels of Protein Structure Primary Structure Unique sequence of AAs Example: Tryptophan-leucine-glycine-glycine-lysine-phenylalanine-serine-leucine Sickle Cell Anemia

Proteins Secondary, Tertiary, Quaternary Structure: The amino acid chain is folded into unique shapes because of hydrogen-bonding This gives each protein a unique shape

Proteins Denaturation: When pH, salt concentration, temperature, and/or other environmental factors are altered, the protein may unravel and lose its shape Biologically inactive Structure + function

Nucleic Acids Structure Function DNA and RNA Made up of long chains of nucleotides CHNOPS Function Carries genetic material from one generation to the next DNA and RNA