The four primary organic macromolecules Proteins (polypeptides) are made up of chains of amino acids There are 20 different types of amino acids, each with the same basic starting structure plus an additional functional group (R) Basic structure of an amino acid

The four primary organic macromolecules Proteins (polypeptides) are made up of chains of amino acids The amino acids are linked together via peptide bonds

The four primary organic macromolecules Proteins (polypeptides) are made up of chains of amino acids Characteristics of the reactive groups cause regions of the protein to attract or repel one another, causing the protein to fold into its final shape

The four primary organic macromolecules Proteins (polypeptides) are made up of chains of amino acids Characteristics of the reactive groups cause regions of the protein to attract or repel one another, causing the protein to fold into its final shape Primary Structure – linear amino acid sequence

The four primary organic macromolecules Proteins (polypeptides) are made up of chains of amino acids Characteristics of the reactive groups cause regions of the protein to attract or repel one another, causing the protein to fold into its final shape Primary Structure Secondary Structure – folding into helices and beta sheets

The four primary organic macromolecules Proteins (polypeptides) are made up of chains of amino acids Characteristics of the reactive groups cause regions of the protein to attract or repel one another, causing the protein to fold into its final shape Primary Structure Secondary Structure Tertiary Structure – folding into final 3D shape

The four primary organic macromolecules Proteins (polypeptides) are made up of chains of amino acids Characteristics of the reactive groups cause regions of the protein to attract or repel one another, causing the protein to fold into its final shape Primary Structure Secondary Structure Tertiary Structure Quaternary Structure – folding into final 3D shape (does not apply to all proteins) Hemoglobin (the oxygen-binding component of blood) is composed of eight proteins: four hemes, two alpha globulins, and two beta globulins

The four primary organic macromolecules Proteins (polypeptides) Structural Receptors Enzymes Actin is an important structural protein in the cellular cytoskeleton and the fibers within muscle cells that enable them to contract

The four primary organic macromolecules Receptors communicate information by causing conformational (shape) changes that transmit a signal cascade (like dominoes falling down) Proteins (polypeptides) Structural Receptors Enzymes Ligands are the generic name for molecules that specifically bind to receptors (cause receptor to undergo conformational change)

The four primary organic macromolecules substrate Proteins (polypeptides) Structural Receptors Enzymes enzyme Enzymes are proteins that speed up chemical reactions by helping to bring molecules together in favorable conformation (biological catalysts) Substrates are the molecules (reactants) bound by the enzyme, the enzyme’s active site specifically binds to them Enzymes are not altered by the chemical reaction and therefore can act again and again to catalyze the reaction over and over

The four primary organic macromolecules Endergonic reactions Proteins (polypeptides) Structural Receptors Enzymes heat Energy is stored in chemical bonds Endergonic reactions are ones where the energy in the bonds of the products exceeds the energy in the bonds of the reactants heat A B Acetic Acid Sodium Bicarbonate Sodium Acetate water HC2H3O2 + NaHCO3 NaC2H3O2 + H2O + CO2 Carbon Dioxide

The four primary organic macromolecules Exergonic reactions Proteins (polypeptides) Structural Receptors Enzymes heat Energy is stored in chemical bonds Endergonic reactions are ones where the energy in the bonds of the products exceeds the energy in the bonds of the reactants Exergonic reactions are ones where the energy in the bonds of the reactants exceeds the energy in the bonds of the products (energy is left over at the end of the reaction It takes energy to break all chemical bonds, even if the reaction is exergonic = activation energy NaCl + H2O NaOH + HCl + heat A B Sodium chloride water Sodium hydroxide Hydrogen chloride

The four primary organic macromolecules Heat speeds up reactions by causing molecules to move faster, thereby encountering one another more frequently and with greater force Enzymes reduce the activation energy needed for a chemical reaction to occur helps reactants encounter one another at necessary angle more quickly Puts stress on bonds so they break more easily Proteins (polypeptides) Structural Receptors Enzymes

The four primary organic macromolecules Most enzyme names end in “ase” - means “to cut” Chemical reactions (metabolism) would happen too slowly in the body without enzymes Proteins (polypeptides) Structural Receptors Enzymes

Click here for Enzyme examples: http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_enzymes_work.html http://www.lew-port.com/10712041113402793/lib/10712041113402793/Animations/Enzyme_activity.html http://www.hillstrath.on.ca/moffatt/bio3a/digestive/enzanim.htm