Biological Macromolecules Chapter 3 Lecture Objectives 1 Understand

Biological Macromolecules Chapter 3 Lecture Objectives: 1. Understand the difference between monomers & polymers 2. Understand the 4 classes of Macromolecules (Carbs, Lipids, Proteins, Nucleic Acids)

Yummy – pizza!

BIOLOGICAL MACROMOLECULES There are four categories of biological macromolecules: or polymers 1. Carbohydrates 2. Lipids 3. Proteins 4. Nucleic acids © 2013 Pearson Education, Inc.

Carbon is very diverse & serves as the backbone to many of these molecules………. Double bond Carbon skeletons vary in length Carbon skeletons may be unbranched or branched Carbon skeletons may have double bonds, which can vary in location Carbon skeletons may be arranged in rings Fig. 3. 01

Carbohydrates “Sugars” Function 1. Dietary energy 2. Storage 3. Structural Named based on size 1. Monosaccharides (glucose & fructose) 2. Disaccharides (lactose & maltose) 3. Polysaccharides (starch & cellulose) © 2013 Pearson Education, Inc.

C Abbreviated structure of glucose C 6 H 12 O 6 Fig. 3. 06 b

Fig. 3. 07 OH H Glucose Galactose H 2 O Lactose A disaccharide

Examples of Polysaccharides Starch granules in potato tuber cells Glycogen granules in muscle tissue (a) Starch Glucose monomer (b) Glycogen Cellulose microfibrils in a plant cell wall Cellulose molecules (c) Cellulose Hydrogen bonds Fig. 3. 09

Lipids Function 1. Energy storage 2. Hormones 3. Insulation & Protection Don’t mix with water because they are nonpolar Examples include 1. Fats (triglycerides) 2. Phospholipids 3. Steroids (testosterone and estrogen) © 2013 Pearson Education, Inc.

Saturated Fats TYPES OF FATS Unsaturated Fats Margarine Plant oils Trans fats Omega-3 fats Fig. 3. 12

Cholesterol Testosterone can be converted by the body to A type of estrogen

Proteins Function 1. Enzymes 2. Structure & Storage 3. Contraction 4. Transport Examples 1. Lactase & hemoglobin © 2013 Pearson Education, Inc.

MAJOR TYPES OF PROTEINS Structural Proteins (provide support) Storage Proteins (provide amino acids for growth) Contractile Proteins (help movement) Transport Proteins (help transport substances) Enzymes (help chemical reactions)

Amino group Carboxyl group Side group The general structure of an amino acid Hydrophobic side group Hydrophilic side group Leucine Serine Fig. 3. 16

5 1 15 10 30 35 20 25 45 40 50 65 55 60 70 Amino acid 85 80 75 95 100 90 115 105 specific sequence of amino acids in a protein is its primary structure 125 129 120

Amino acids (b) Secondary structure (c) Tertiary structure (d) Quaternary structure (a) Primary structure Pleated sheet A protein with four polypeptide subunits Hydrogen bond Polypeptide Alpha helix Fig. 3. 20

Protein Shape – SUPER important A protein’s three-dimensional shape 1. typically recognizes and binds to another molecule 2. enables the protein to carry out its specific function in a cell. © 2013 Pearson Education, Inc.

SEM lu G o r His Leu Thr P 6 7. . . 146 Val 1 2 4 5 Normal hemoglobin SEM Normal red blood cell Val 1 Sickled red blood cell 3 al Glu V o r His Leu Thr P 6 7. . . 146 2 3 4 5 Sickle-cell hemoglobin Fig. 3. 19

Nucleic Acids Function 1. Store information 2. Provide instruction Examples 1. DNA & RNA © 2013 Pearson Education, Inc.

Sugar-phosphate backbone Nucleotide T G C T A Base pair T A Hydrogen bond G A T A A C T A G Bases T C G A (a) DNA strand (polynucleotide) T (b) Double helix (two polynucleotide strands)

Large biological Functions molecules Carbohydrates Components Dietary energy; storage; plant structure Monosaccharide Lipids Proteins Long-term energy storage (fats); hormones (steroids) Enzymes, structure, storage, contraction, transport, etc. Components of a triglyceride Side group Examples Monosaccharides: glucose, fructose; Disaccharides: lactose, sucrose; Polysaccharides: starch, cellulose Fats (triglycerides); steroids (testosterone, estrogen) Lactase (an enzyme); hemoglobin (a transport protein) Amino acid Nucleic acids Information storage T Nucleotide DNA, RNA