Glucose Molecule

Macromolecules Carbohydrates, proteins, and nucleic acids are polymers Polymers – long molecules made from building blocks linked by covalent bonds Monomers – the building blocks to polymers Monomers are connected to form polymers by a condensation reaction, or specifically a dehydration synthesis, named because a water molecule is produced. Polymers are broken down into monomers by hydrolysis, water is added to break the bonds.

Dehydration Synthesis and Hydrolysis Dehydration reactions build macromolecules – enzymes facilitate this process Hydrolysis breaks down macromolecules; also with the aid of enzymes. Example – digestion of food

Monomers to Polymers Polymers of living things are made from only 40 to 50 common monomers These monomers have the potential of producing thousands of different macromolecules These macromolecules are responsible for the great diversity among individuals of a species and even greater diversity from species to species

Monomers to Polymers Class Monomers or Subunits Functions CarbohydratesMonosaccharides Energy, raw materials, energy storage, structural compounds Lipids Glycerol and fatty acids = fats Energy storage, cell membranes, steroids, hormones ProteinsAmino acids Enzymes, transport, movement, receptors, defense, structure Nucleic AcidsNucleotides Heredity, code for amino acid sequence

Carbohydrates Include sugars and their polymers Monosaccharide – single sugar or simple sugar (ex. glucose) Disaccharide – double sugar, formed by two monosaccharides bonded together (ex. sucrose – made from the monosaccharides glucose and fructose) Polysaccharide – many monosaccharides bonded together (ex. starch – long chain of glucose molecules)

Monosaccharides Have the general molecular formula of (CH 2 O) n Example: glucose (C 6 H 12 O 6 ) a source of energy for cells Name of monosaccharides usually ends in -ose Have a carbonyl group and multiple hydroxyl groups Carbon skeleton ranges from 3 to 7 carbons The diversity of monosaccharides is due to the arrangements of parts around the carbons

Monosaccharides

Disaccharides Joined by a glycosidic linkage, covalent bond b/w two mono. by a dehydration reaction

Polysaccharides Formed from a few hundred to a few thousand monosaccharides joined by a glycosidic linkage Serve two main purposes: storage and structure

Storage Polysaccharides Starch –major storage polysaccharide in plants –Made up of glucose monomers –Source of stored energy –Humans and other animals hydrolyze the starch in potatoes and grains for a source of energy Glycogen –storage polysaccharide in animals –Stored mainly in the liver and muscle cells –Reserves only last about 1 day in humans

Structural Polysaccharides Cellulose –Major component in plant cell walls –Made up of glucose monomers –Differs from starch in the linkage of the glucose monomers –Many animals, including humans, are unable to digest cellulose Chitin –Makes up the exoskeletons of arthropods –Hardens with the aid of calcium carbonate –Also found in the cell walls of fungi

Cellulose