Bio 120 CHP 5 Lecture Notes
Bio 120 CHP 5 Lecture Notes Biology 120
Popular in General Biology
Popular in Biology
This 4 page Class Notes was uploaded by Kaity Notetaker on Sunday September 18, 2016. The Class Notes belongs to Biology 120 at Grand Valley State University taught by Jennifer J Jenkins in Fall 2016. Since its upload, it has received 7 views. For similar materials see General Biology in Biology at Grand Valley State University.
Reviews for Bio 120 CHP 5 Lecture Notes
Report this Material
What is Karma?
Karma is the currency of StudySoup.
Date Created: 09/18/16
Chapter 5: Structure and Function of Large Biological Molecules I. Introduction Macromolecules: large molecules made up of many, many atoms bonded together Some are polymers = many parts The building blocks of a polymer are called monomer = single part Building a polymer requires a dehydration reaction (removing water molecule) Breaking down a polymer requires a hydrolysis reaction (adds water molecule to break) II. Large Biological Molecules – 4 major types a. Carbohydrates Sugars and polymers of sugar Molecules made up of CH2O Multiple hydroxyl group = OH Carbonyl group, C=O 1. Monosaccharides 3-7 carbons long Difference between ketone and aldose is depending on where the carbonyl group is located (aldehyde = end) Glucose can be linear but usually ring shaped Functions: source of energy, our cells use glucose for ATP Building blocks for bigger carbohydrates 2. Disaccharides: Carbohydrates made up of 2 monomers linked together Ex: Maltose, Sucrose Glyosidic linkage: Disaccharides requires between 2 monomers (covalent bonds form because of dehydration reaction) Function: source of energy 3. Polysaccharides: Carbohydrates made up of many sugar monomers linked together Starch: polymer of glucose Function: energy source Plants use starch as a form of energy because starches are long living and can be stored easily Glycogen: polymer of glucose Located in plants, cell walls Function: energy source Animals DON’T store all their energy as glycogen because extra will be stored as fat, which are very efficient as a form of energy storage Chitin: Polymer made up of modified glucose monomers Found in crustaceans and insects (exoskeleton) And in fungi cell wall b. Lipids: something that has no or little affinity of water (hydrophobic) Not polymers Fats (triacylglycerol) carboxyl group One glycerol and 3 fatty acids Linkages are called Ester Linkage Why are fats hydrophobic? They are non-polar covalent bonds so they have no partial charges Function: Storage form of energy in animals, insulation, cushioning 1. Saturated Fat: Carbons are fully saturated with hydrogen (straight chains packed together tightly) 2. Unsaturated Fat: Carbons are not fully saturated with hydrogen. Presence of carbon double bond produces kinks in the hydrocarbon tail so that the unsaturated fats cannot pack tightly together 3. Trans Fat: (Hydrogenation) Turns unsaturated fats to have a longer shelf life. Elevates “bad cholesterol” (solid a room temperature) 4. Phospholipids Structure: hydrophilic head (glycerol) and hydrophobic tails (2 fatty acids), phosphate group on top of head. Amphipathic properties: head attracts to water because phosphate group has a negative charge Located in cell membrane (bilayer phospholipid), regulates what goes in and out of the cell 5. Steroids (hydrophobic) Structure: Carbon skeleton made up of 4 fused rings to which function groups are attached Many functions Ex: Cholesterol, Pre-cursor (used to make hormones: testosterone, vitamin D, bile salts) Component of cell membrane (myelin sheath) Carried in blood by lipid proteins (HDL, LDL) Difference between good and bad cholesterol? HDL – takes cholesterol back to liver, removes cholesterol from artery wall LDL – Cholesterol deposited in artery walls – which can damage walls, block arteries c. Proteins: Polymers of amino acid 1. Amino acid (building blocks of proteins) Contains a central carbon bonded to an amino group, carboxyl, and hydrogen with a side chain that can vary 2. Peptide bonds (form between amino acids) Dehydration reaction to form bond Covalent bond Where does it form? Carbon between carboxyl group of 1 amino acid and nitrogen between carboxyl group of the 2 ndamino acid Keeps adding to the right Proteins are made in ribosomes Polypeptides have polarity 3. Structure: Complex, unique 3-D shapes Structure influences function Creates different shapes – think “knitting” Primary = amino acid sequence Secondary = folding or coiling of amino acid chain due to regular hydrogen bond that occurs within the backbone between Hydrogen, Nitrogen, and Oxygen Tertiary = irregular contortions of the molecule; stabilizes the 3-D structure. This involves bonding between side chains Quaternary = 2 or more poly peptide chains More than one string of amino acid Sickle cell disease/ change of amino acid in hemoglobin 4. Functions of Proteins Movement of muscle, transportation, structure, communication (signaling & receptor), enzymes, defense (antibodies of immune system) Digression – denatured: protein changes 3-D shape Ex: Mad Cow diseases Infectious agent: protein called a prion 5. Protein Folding Chaperonin molecules: enable polypeptides to undergo appropriate folding (construct 3-D shape) Nucleic acids: polymers of nucleotides (single monomer) (DNA&RNA) Structure: 3 parts Phosphate group Pentose sugar (deoxyribose or ribose) Nitrogenous base Pyrimidine (cytosine, thymine, uracil (only in RNA)) Purine (adenine, guanine) DNA AND RNA = double stranded helix Important in the making of proteins (located in the nucleus)