Macromolecules Carbohydrates Proteins Lipids Nucleic Acids

Carbohydrates Function: fuel and building material; made of C + H2O. Monosaccharides (simple or single sugars). Ex: glucose, galactose, fructose Disaccharides (double sugars). Ex: sucrose, fructose, maltose Polysaccharides are long chains of monosaccharides. Ex: cellulose (starch in flour) glycogen (in animals)

Carbohydrates Monosaccharides have molecular formulas that are some multiple of CH2O. Ex: glucose and galactose C6H12O6. Most names for sugars end in –ose: glucose, ribose. Monosaccharides form disaccharides by dehydration. (chemical reaction) SEE NEXT TWO SLIDES

Carbohydrates Polysaccharides are polymers of hundreds to thousands of monosaccharides. Function in energy storage (used as needed). Ex: starch (in plants) and glycogen (in animals’ livers) Function as strong building materials. Ex: cellulose

Lipids Lipids are hydrophobic: They do NOT like water! In a triglyceride, 3 fatty acids (same or different) are joined to glycerol. 3 fatty acids glycerol

Lipids A saturated fat has no carbon-carbon double bonds, and it is straight. They pack together – solid at room temperature. Unsaturated fats have one or more carbon-carbon double bonds, and they bend. They can’t get close to each other, so they are liquid at room temperature.

Lipids Saturated fats come from animal products. Ex: butter, lard A diet rich in saturated fats may contribute to cardiovascular disease (heart attack, stroke) through plaque deposits in arteries; obesity, diabetes.

Lipids Unsaturated fats come from plant & fish products. Ex: olive oil, corn oil, safflower oil, fish oils. Generally considered healthier for the heart.

Lipids Functions of lipids Nutrition: 1g of fat contains twice as much energy as 1g of carbohydrate. Protection: cushions vital organs and insulates them. This subcutaneous layer is especially thick in whales, seals and most other marine mammals.

Lipids Functions of lipids Phospholipids: MAJOR components of cell membranes. Have two fatty acids attached to glycerol and a phosphate group at the third position.

Lipids Functions of lipids Waxes reduce water loss by plants. Steroids Carnauba wax Steroids Cholesterol is a component in animal cell membranes. Many steroids are hormones.

Nucleic acids All molecules of the body are programmed by a genetic code in the organism’s DNA, a polymer of nucleic acids. Nucleic acids store and transmit hereditary in- formation. A nucleic acid

Nucleic acids There are two types of nucleic acid polymers: Ribonucleic acid (RNA) Single-stranded. Contains adenine, guanine, cytosine, and uracil. Sugar is ribose. Deoxyribonucleic acid (DNA) Double stranded. Contains adenine, guanine, cytosine, and thymine. Sugar is deoxyribose.

Proteins Humans have at least 30,000 different proteins, each with a unique structure and function. Functions include structural support, storage, transport of materials, intercellular signaling, movement, and defense. Enzymes are one class of proteins that regulate metabolism by moderating chemical reactions. All proteins are structurally complex in 3 dimensions. All are constructed from the same set of 20 monomers, called amino acids.

Proteins Amino acids are joined by dehydration; the resulting covalent bond is called a peptide bond. Polymers of amino acids are called polypeptides.

Proteins A protein’s function depends on its precise twisting, folding, and coiling into a unique shape. The order of amino acids determines what the three- dimensional shape will be. Folding of a protein occurs spontaneously: an emergent property resulting from its specific molecular order.

Proteins In individuals with sickle cell disease, abnormal hemoglobins develop because of a single amino acid substitution.

Proteins Fibrous proteins are long, insoluble molecules . For movement (muscle fibers); For structure and support.   Collagen in skin. Cartilage connects tissues. Keratin is found in hair, horns, wool, nails, and feathers.

Proteins Globular proteins are soluble and form compact spheroidal molecules in water.   Transport proteins and receptor proteins are globular. Enzymes are globular proteins that are in- volved in chemical reactions (enzymes generally end in –ase). Antibodies Hemoglobin – transport of oxygen

Proteins Transport proteins and receptor proteins in the cell membrane capture chemicals in the blood and may move them into the cell.

Proteins A protein’s shape can change in response to changes in pH, salt concentration, temperature. These forces disrupt the bonds that maintain the protein’s shape. This is called denaturation. Then the protein won’t work right.