Warm up What is the difference between micro and macro? How is organic chemistry defined? Carbon based compounds

The Structure and Function of Large Biological Molecules Chapter 5 The Structure and Function of Large Biological Molecules

You Must Know The role of dehydration synthesis in the formation of organic compounds and hydrolysis in the digestion of organic compounds. How to recognize the 4 biologically important organic compounds (carbs, lipids, proteins, nucleic acids) by their structural formulas. The cellular functions of all four organic compounds. The 4 structural levels of proteins How proteins reach their final shape (conformation) and the denaturing impact that heat and pH can have on protein structure

ie. amino acid  peptide  polypeptide  protein Monomers Polymers Macromolecules Small organic Used for building blocks of polymers Connects with condensation reaction (dehydration synthesis) Long molecules of monomers With many identical or similar blocks linked by covalent bonds Giant molecules 2 or more polymers bonded together ie. amino acid  peptide  polypeptide  protein larger smaller

Dehydration Synthesis (Condensation Reaction) Hydrolysis Make polymers Breakdown polymers Monomers  Polymers Polymers  Monomers A + B  AB AB  A + B Condensation (DEHYDRATION) reactions: 2 molecules are covalently bonded to each other through loss of a water molecule. When a polymer is forming, each monomer contributes part of the water like a hydroxyl group or hydrogen. This reaction is repeated as monomers are added to the chain one by one. Cell uses energy to carry out this process and only occurs with the help of enzymes. Hydrolysis: BREAKING DOWN monomers. Break with water Bonds are broken by adding water molecules Hydrogen from water bonds to one monomer and the hydroxyl group to the other, in our body this happens in digestion, food is in the form of polymers and too big to enter the cells. enzymes attack polymer, speeding up hydrolysis + H2O + + H2O +

Differ in position & orientation of glycosidic linkage III. Carbohydrates Fuel and building material Include simple sugars (fructose) and polymers (starch) Ratio of 1 carbon: 2 hydrogen: 1 oxygen or CH2O monosaccharide  disaccharide  polysaccharide Monosaccharides = monomers (eg. glucose, ribose) Polysaccharides: Storage (plants-starch, animals-glycogen) Structure (plant-cellulose, arthropod-chitin) Monosaccharides- CH2O fomula glucose is the most common. Has carbonyl group, multi hydroxyl groups Depending on the location of the hydroxyl group they are either aldose- aldehyde sugar or ketose- keytone sugar. glucose- aldose, fructose –ketose (isomer of glucose) Another way to classify sugars is based on the size of the carbon skeleton, their spatial arrangement Usually drawn as chains but in aqueous solutions form rings. Disaccharide- 2 monosaccharide joined by glycosidic linkage-covalent bond between monosaccharide by dehydration reaction. example: maltose, lactose Polysaccharides- macromolecule made of a few 100 monosaccharides store material structural- building material that protect the cell or whole organism Differ in position & orientation of glycosidic linkage

The structure and classification of some monosaccharides Location of carbonyl group Length of carbon Spatial arrangements

Linear and ring forms of glucose Chemical equilibrium between linear and ring structures favors the formation of rings. Carbon 1 bonds to oxygen attached to carbon 5 Linear and ring forms of glucose

Carbohydrate synthesis 2 glucose bonding by creating h2o and forming a glycosidic linkage between carbon 1 and 4 Glycosidic linkage 1 and 2 Carbohydrate synthesis

Cellulose vs. Starch Two Forms of Glucose:  glucose &  glucose Differ in the placement of the hydroxyl group. Cellulose tough walls that enclose plants cells. Most abundant organic compound on earth beta Starch made of glucose, stored in chloroplasts (STORED ENERGY) alpha

Cellulose vs. Starch Starch =  glucose monomers Cellulose =  glucose monomers

Storage polysaccharides of plants (starch) and animals (glycogen)

Structural polysaccharides: cellulose & chitin (exoskeleton)

II. Lipids Fats (triglyceride): store energy Glycerol + 3 Fatty Acids saturated, unsaturated, polyunsaturated Steroids: cholesterol and hormones Phospholipids: lipid bilayer of cell membrane hydrophilic head, hydrophobic tails Little or no affinity to water Not considered a polymer but are large Assemble from smaller molecules by dehydration Glycerol= alcohol group with carbon each with a hydroxyl group Fatty acid= long chain with carboxyl at one end. (HYDROPHOBIC) Fats separate becuz water molecules H-bonds to one another and exclude fats. Hydrophilic head Hydrophobic tail

Glycerol and 3 fatty acids through dehydration water molecule removed for each fatty acid joined to gycerol

Have some C=C, result in kinks Saturated Unsaturated Polyunsaturated “saturated” with H Have some C=C, result in kinks In animals In plants Solid at room temp. Liquid at room temp. Eg. butter, lard Eg. corn oil, olive oil

The structure of a phospholipid 2 fatty acids attached to glycerol, phosphate attached to the 3rd hydroxyl group of glycerol. Which has a negative charge. Polar molecules can link to phosphate group. Cell membrane. Phospholipids bilayer The structure of a phospholipid

Hydrophobic/hydrophilic interactions make a phospholipid bilayer

Molecule from which most other steroids are synthesized Molecule from which most other steroids are synthesized. Vary in functional group as seen in the gold Cholesterol, a steroid

I. Proteins “Proteios” = first or primary 50% dry weight of cells Contains: C, H, O, N, S Myoglobin protein

Protein Functions (+ examples) Enzymes (lactase) Defense (antibodies) Storage (milk protein = casein) Transport (hemoglobin) Hormones (insulin) Receptors Movement (motor proteins) Structure (keratin)

Overview of protein functions

Overview of protein functions

Four Levels of Protein Structure Primary Amino acid (AA) sequence 20 different AA’s peptide bonds link AA’s

Amino Acid “amino” : -NH2 “acid” : -COOH R group = side chains Properties: hydrophobic hydrophilic ionic (acids & bases) “amino” : -NH2 “acid” : -COOH

Four Levels of Protein Structure (continued) Secondary Gains 3-D shape (folds, coils) by H-bonding Alpha (α) helix, Beta (β) pleated sheet

Basic Principles of Protein Folding Hydrophobic AA buried in interior of protein (hydrophobic interactions) Hydrophilic AA exposed on surface of protein (hydrogen bonds) Acidic + Basic AA form salt bridges (ionic bonds). Cysteines can form disulfide bonds.

Four Levels of Protein Structure (continued) Tertiary Bonding between side chains (R groups) of amino acids H bonds, ionic bonds, disulfide bridges, van der Waals interactions

Four Levels of Protein Structure (continued) Quaternary 2+ polypeptides bond together

amino acids  polypeptides  protein Bonding (ionic & H) can create asymmetrical attractions

Chaperonins assist in proper folding of proteins

Protein structure and function are sensitive to chemical and physical conditions Unfolds or denatures if pH and temperature are not optimal

change in structure = change in function

Function: store hereditary info II. Nucleic Acids Function: store hereditary info DNA RNA Double-stranded helix N-bases: A, G, C, Thymine Stores hereditary info Longer/larger Sugar: deoxyribose Single-stranded N-bases: A, G, C, Uracil Carry info from DNA to ribosomes tRNA, rRNA, mRNA, RNAi Sugar: ribose

Nucleotides: monomer of DNA/RNA Nucleotide = Sugar + Phosphate + Nitrogen Base

Nucleotide phosphate A – T Nitrogen G – C base 5-C sugar Purines Pyrimidines Adenine Guanine Cytosine Thymine (DNA) Uracil (RNA) Double ring Single ring 5-C sugar

Information flow in a cell: DNA  RNA  protein