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 carbon atoms

2.5 Carbohydrates Simple Carbohydrates –Monosaccharides are sugars with 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

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

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

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

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

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.

2.8 Nucleic Acids Components of a nucleotide –Phosphate –Pentose sugar –Nitrogen-containing base

2.8 Nucleic Acids DNA Structure

2.8 Nucleic Acids

ATP (Adenosine Triphosphate)

2.8 Nucleic Acids ATP (Adenosine Triphosphate) –A high energy molecule –ATP undergoes hydrolysis and energy is released

2.8 Nucleic Acids