Biological Macromolecules
Carbon! Very abundant (15th most on the planet!) tetravalent! Can create an absurd amount of isomers!
Macromolecules Carbohydrates- Sugars: short-term energy storage and structural support. Lipids- Fats, oils, waxes: long-term energy storage, cell membrane structure, and cell signaling. Proteins- function in all cellular processes. Nucleic Acids- DNA and RNA: information storage and expression. All macromolecules are synthesized via condensation reactions and decomposed via hydrolysis reactions. Most macromolecules are polymers.
Monomers ---> Polymers Monomer : simplest unit polymer: a large molecule made up of repeat units (monomers)
Anabolism Anabolism - build up complexity Condensation reaction - When two smaller molecules come together to form one large molecule with the help of an enzyme. They release a water molecule. EX: protein synthesis, DNA synthesis, photosynthesis, synthesis of macromolecules
Catabolism Reactions that break down complexity. Hydrolysis - When one larger molecule breaks down into two smaller molecules with the help of an enzyme. Water is used in this reaction. Ex: Digestion of food, cell respiration, digestion of carbon by decomposers
Carbohydrates (1C:2H:1O) Monomer: Monosaccharide Polymer: Polysaccharide Sugars and starches
Carbohydrates (continued) Monosaccharides and disaccharides (small) are predominately used for energy
Glucose-- you must be able to draw these!
Starch Found only in plants links together -glucose (all link downward) and is curved hydrophilic, but too large to dissolve useful for storage and won t change tonicity temporary storage when photosynthesis is too fast!
Glycogen similar to starch, made in animals and some fungi very branched so more compact same function as starch
Cellulose uses β-glucose Straight chain, not curved form bundles using hydrogen bonds high tensile strength
Herbivores - How do they break down the cellulose?
Lipids (C, H, and O - more C and H than O) Monomers: glycerols and fatty acids Polymers: many - 3 majors: triglycerides, phospholipids, and steroids Used for long term energy storage and insulation
Long term energy storage Why fats? Why not carbs? amount of energy released from a fat in cell: twice of carbs insoluble in water: if we stored glucose for long-term storage, it would swell because glucose attracts water!! Secondary roles poor conductors of heat - heat insulator (Think, where do we keep our fat stored?) Shock absorber! (Where else do we keep fats?)
made of: 1 glycerols and 3 fatty acids found in adipose tissue of animals and in the oil of sunflower seeds fats - liquid at body temp. and solid at room temp oils - liquid at both Used as energy storage Do not conduct heat well Triglycerides
Fatty Acids Can be saturated or unsaturated due to the fatty acids Saturated fatty acid: no double bond between the carbons Found in: meats, dairy, chips, and pastries Solid at room temp - no gaps Unsaturated: at least one double bond between carbons monounsaturated - one double bond polyunsaturated - more than one double bond Found in: nuts, avocados, and olives Cis v. Trans unsaturated fatty acids Cis - (same side) Liquid at room temp - gaps Trans - (different sides) solids - artificially produced
Proteins (CHONS) Accomplish all of life s functions - builders and doers. Monomer: amino acids Each amino acid is joined to the next amino acid through a peptide bond (covalent) during the process of translation
Amino Acids Every amino acid has these components in common: central or -carbon amine group carboxyl group single hydrogen Each has a different variable group (R) and each R-group is wildly different.
Peptide Chains Chains of amino acids (peptide chains or poly peptides) have directionality. They always link up carboxyl group to amine group
Endless combinations For every amino acid used in a polypeptide chain, the number of possible sequences can be calculated n = number of amino acids in the chain 20 = number of most common amino acid possible sequences = 20n think about if a chain had 35,000 amino acids!
Gene Protein typical cells produce polypeptides with thousands of different sequences and need to store the information of how. Where do they store this? In genes! (DNA!) Genes are typically longer than they need to be...why?
4 levels of protein structure Primary (1 ) Structure sequence of amino acids formed by peptide bonds How does the cell know the correct order?
4 levels of protein structure Secondary (2 ) Structure Regular repeating 3-D structure Formed by hydrogen bonds (intermolecular) of the C-N backbone (NO R-GROUP) Why would all proteins have the same repeating structure?
4 levels of protein structure Tertiary (3 ) Structure Specific 3-D shape of the protein conformation Interactions of Rgroups
4 levels of protein structure Quaternary (4 ) Structure Specific 3-D shape of a protein made up of more than one polypeptide chain Why would some proteins be made up of more?
Denature Conformation Function If the conformation (which level is that again?) is changed, the function will change. Denaturation - change to the conformation of a protein. What can denature a protein?
Function Catalysis: Selective acceleration of chemical reactions - enzymes (SO MANY!) Muscle Contraction: Movement (actin, myosin) Cytoskeletons - tubulin to give structure to cells and move chromosomes Tensile Strength: fibrous proteins (collagen) Blood Clotting - plasma proteins Transport of nutrients and gas - in blood move CO2 and O2 (hemoglobin) Cell adhesion - cells to stick together Membrane Transport - facilitated diffusion and active transport Hormones: coordinates cellular activities (Insulin) Receptor: binding sites in cell membranes and cytoplasm Packing of DNA - histones help wrap DNA Defense: Protection from disease (antibodies)
Individuality Proteome - all of the proteins produced by a cell, tissue, or organism Each individual has a unique set of proteins that he/she can create or a unique proteome
Things to Do! Drawings Ensure you have drawings for all molecules on that white handout on there AND IN YOUR NOTEBOOK Read Enzymes 2.5 in text
Without Notes Complete the following drawings and turn in: glucose ribose saturated fatty acid generalized amino acid
Nucleic Acids (C,H,O,N,P) Monomer: nucleotide Polymer: Nucleic Acid DNA and RNA store and transmit genetic information
Nucleotides Composed of three components: phosphate group (negative charge) pentose (5 carbon) sugar nitrogenous base (either 1 or 2 rings) To link two nucleotides together, a covalent bond forms between the phosphate of one and the sugar of another
DNA v. RNA Key differences: pentose sugar DNA = deoxyribose RNA = ribose bases DNA = adenine, guanine, cytosine, & thymine RNA = adenine, guanine, cytosine, & uracil Size DNA = double stranded RNA = single stranded
2 functions: stores all information on the formation of proteins and RNA is heritable!!! Structure 2 strands each individual strand is a series of nucleotides that are covalently bonded to each other (backbone) Each strand runs antiparallel to the other -5 to 3 and the other is 3 to 5 the two strands are joined in the middle with hydrogen bonds between the nitrogenous base complementary base pairing A - T (2 bonds) G - C (3 bonds) purine (A & G) always opposite DNA
Watson and Crick Published a paper on the discovery of the structure Ethics :(
Wrap-up Video Summary/Extension Add to notes as needed >>>For Next Class: Quiz over macromolecules Site to help study-- http://ibworld.me/biochemistry.html