2 5 Carbohydrates 2 5 Carbohydrates Some Functions

2. 5 Carbohydrates

2. 5 Carbohydrates • Some Functions: – Quick fuel – Short-term energy storage – Structure of organisms – Cell to cell recognition

2. 5 Carbohydrates • Simple Carbohydrates

2. 5 Carbohydrates • Simple Carbohydrates – Monosaccharides are sugars with 3 - 7 carbon atoms

2. 5 Carbohydrates • Simple Carbohydrates – Monosaccharides are sugars with 3 - 7 carbon atoms – Pentose refers to a 5 -carbon sugar – Hexose refers to a 6 -carbon sugar

2. 5 Carbohydrates Three ways to represent the structure of glucose.

2. 5 Carbohydrates • Disaccharides contain two monosaccharides.

2. 5 Carbohydrates • Polysaccharides are long polymers that contain many glucose subunits.

2. 5 Carbohydrates • Polysaccharides are long polymers that contain many glucose subunits. – Starch is the storage form of glucose in plants.

2. 5 Carbohydrates • Polysaccharides are long polymers that contain many glucose subunits. – Starch is the storage form of glucose in plants. – Glycogen is the storage form of glucose in animals.

2. 5 Carbohydrates • Polysaccharides are long polymers that contain many glucose subunits. – Starch is the storage form of glucose in plants. – Glycogen is the storage form of glucose in animals. – Cellulose can be found in the cell walls of plants.

2. 5 Carbohydrates

2. 6 Lipids

2. 6 Lipids • Some Functions: – Energy Storage – Found in the plasma membrane – Component of steroid hormones Lipids do not dissolve in water

2. 6 Lipids • Some Functions: – Energy Storage – Found in the plasma membrane – Component of steroid hormones Lipids do not dissolve in water Lipids are electrically neutral

2. 6 Lipids • Fats and Oils

2. 6 Lipids • Fats and Oils – Fats • Usually of animal origin • Solid at room temperature

2. 6 Lipids • Fats and Oils – Fats • Usually of animal origin • Solid at room temperature – Oils • Usually of plant origin • Liquid at room temperature

2. 6 Lipids • Functions of Fats

2. 6 Lipids • Functions of Fats – Long-term energy storage – Insulation against heat loss – Protection of major organs

2. 6 Lipids Synthesis and degradation of a fat molecule

2. 6 Lipids Emulsification

2. 6 Lipids • Saturated and Unsaturated Fatty Acids

2. 6 Lipids • Saturated and Unsaturated Fatty Acids – Fatty acids are hydrocarbon chains that end with -COOH.

2. 6 Lipids • Saturated and Unsaturated Fatty Acids – Fatty acids are hydrocarbon chains that end with -COOH. • Saturated fatty acids: No double covalent bonds between carbon atoms • Unsaturated fatty acids: Double bonds between carbon atoms

2. 6 Lipids Saturated Fatty Acid Unsaturated Fatty Acid

2. 6 Lipids • Phospholipids

2. 6 Lipids • Phospholipids – Comprised of 2 fatty acids + a phosphate group – Primary components of cellular membranes

2. 6 Lipids

2. 6 Lipids • Steroids

2. 6 Lipids • Steroids – All steroids have four adjacent rings.

2. 6 Lipids • Steroids – All steroids have four adjacent rings. – Examples: § Cholesterol § Testosterone § Estrogen

2. 6 Lipids

2. 7 Proteins • Proteins have important functions in cells. – Proteins such as keratin and collagen have structural roles. – Proteins are also enzymes that speed up the chemical reactions of metabolism. – Proteins such as hemoglobin are responsible for the transport of substances within the body. – Proteins also transport substances across cell membranes.

2. 7 Proteins • Proteins have important functions in cells. – Proteins form the antibodies of the immune system that defend the body from disease. – Proteins such as insulin are hormones that regulate cellular function. – Contractile proteins such as actin and myosin allow parts of cells to move and muscles to contract.

2. 7 Proteins • Proteins are comprised of amino acids.

2. 7 Proteins • Amino acids – Amino group (-NH 2) – Acidic group (-COOH) – R group (remainder)

2. 7 Proteins

2. 7 Proteins • Peptides – A polypeptide is a single chain of amino acids. – A peptide bond joins two amino acids.

2. 7 Proteins

2. 7 Proteins • Levels of Protein Organization – The structure of a protein has three or four levels of organization. – The final shape of a protein is very important to its function.

2. 7 Proteins

2. 8 Nucleic Acids • DNA (deoxyribonucleic acid)

2. 8 Nucleic Acids • DNA (deoxyribonucleic acid) • RNA (ribonucleic acid)

2. 8 Nucleic Acids • DNA stores genetic information. • DNA codes for the order of amino acids in a protein. • RNA is an intermediary in the sequencing of amino acids into a protein.