MACROMOLECULES

The Big Idea… Living organisms are made up of carbon-bases molecules

Objectives Describe the role of carbon in living organisms Summarize the four major families of biological macromolecules Compare the functions of each group of macromolecules

4 essential elements to life {Q#1} 95% of your body weight

The element CARBON

Carbon Component of almost all biologic molecules Life on Earth is thought to be “carbon-based.” Organic Chemistry – a branch of chemistry devoted completely to the study of carbon- based compounds

Carbon molecule Bohr’s diagram 4 valence electrons Capable of forming 4 covalent bonds

Carbon molecules

Macromolecules Prefix: Macro- means: large aka: Biomolecules aka: Polymers Prefix: Poly- means: many Repeating units of identical monomers building blocks 4 categories (pg. 167) Carbohydrates Lipids Proteins Nucleic acids

Carbohydrates Carbon, Hydrogen, and Oxygen in a 1:2:1 ratio Building blocks: monosaccharides “Simple sugars” Carbon, Hydrogen, and Oxygen in a 1:2:1 ratio

How we use carbohydrates Mono- and disaccharides are an energy source Glucose (chief energy source) Sucrose Lactose Polysaccharides are energy storage molecules Glycogen (liver and muscle cells)

Polysaccharides in nature Cellulose Plant cell walls Chitin Exoskeleton of insects and crustaceans Fungi cell wall

Lipids Carbon, Hydrogen, Oxygen (CHO) Fats, oils, and waxes Building blocks of lipids are fatty acids Large, non-polar molecules Hydrophobic - will not dissolve in water Serve as barriers

Recall the cell membrane Phospholipid bi-layer

Phospholipid review Heads are polar and attract water hydrophilic Tails are non-polar and repel water hydrophobic

Lipids Triglyceride Made of glycerol head and 3 fatty acid chains

Lipids Steroids Cholesterol Hormones Testosterone Estrogen

Lipids in nature Cutin – a waxy coating covering leaves Chlorophyll – green pigment molecule Beeswax – honeycomb

Proteins Building blocks – amino acids Carbon, Hydrogen, Oxygen, Nitrogen, and sometimes Sulfur (CHON S) 2 functional groups Amino Group … -NH2 Carboxyl Group … -COOH

Amino Acids Same general structure 20 different amino acids Combine in various ways to form polypeptides which join together to make a protein Peptide bonds join amino acids together to form proteins in a condensation reaction (removal of water molecule)

3-D Protein Structure Primary – simple arrangement of the amino acids as they line up, in order, to form the protein

3-D Protein Structure Secondary - folding into a helix or pleated sheet (pg. 170)

3-D Protein Structue Tertiary – globular structure, as in hemoglobin

3-D Protein Structure Quaternary Structure – combination with other proteins

Protein Functions 15 percent of total human body mass Hair, skin, muscles Cells have about 10,000 different proteins Transport proteins Enzymes – thousands to control chemical reactions (aka biologic catalysts)

Nucleic Acids Building blocks – nucleotides Composed of Carbon, Hydrogen, Oxygen, Nitrogen, and Phosphorus atoms Nucleotides are made of 3 parts: Phosphate Nitrogenous base Ribose (5 carbon) sugar

Functions of Nucleic Acids Carry the genetic information in cells DNA – deoxyribose nucleic acid Contains all the instructions for making every protein needed in a living organism RNA – ribose nucleic acid Copies and transfers the genetic information in DNA to ribosomes so that proteins can be made

Nucleotide ATP ATP is a special nucleotide with 3 phosphate groups Storehouse of chemical energy You will learn more about ATP in chapter 8

8 review questions…

REVIEW Carbohydrates, lipids, proteins, and nucleic acids are M___________________. Proteins are made from A_______ A________ that are joined by P________ B__________. L____________ make up fats, oils, and waxes. DNA and RNA are examples of N____________ A________.

REVIEW Which two elements are always found in amino acids? A. Nitrogen and Sulfur Carbon and Oxygen Hydrogen and Phosphorus Sulfur and Oxygen

REVIEW Which joins amino acids together? A. Peptide bonds B. Hydrogen Bonds C. van der Waals forces D. ionic bonds

REVIEW Which substance is not part of a nucleotide? A. a phosphate B. a base C. a sugar D. water