Unit 1, Chapter 3 Biological Macromolecules PDF

Summary

This document is a lecture presentation on biological macromolecules. The presentation covers the four main classes: carbohydrates, lipids, proteins, and nucleic acids. It also discusses the structure, function, and types of molecules in each class.

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Unit 1, Chapter 3 Biological Macromolecules Biology 2e Ch 3 Objectives: Understand macromolecule synthesis Explain dehydration (or condensation) and hydrolysis reactions Discuss the role of carbohydrates in cells and in the extracellular materials of animals and plants Explain ca...

Unit 1, Chapter 3 Biological Macromolecules Biology 2e Ch 3 Objectives: Understand macromolecule synthesis Explain dehydration (or condensation) and hydrolysis reactions Discuss the role of carbohydrates in cells and in the extracellular materials of animals and plants Explain carbohydrate classifications List common monosaccharides, disaccharides, and polysaccharides Describe the four major types of lipids Explain the role of fats in storing energy Differentiate between saturated and unsaturated fatty acids Describe phospholipids and their role in cells Define the basic structure of a steroid and some steroid functions Explain how cholesterol helps maintain the plasma membrane's fluid nature Describe the functions proteins perform in the cell and in tissues Discuss the relationship between amino acids and proteins Explain the four levels of protein organization Describe the ways in which protein shape and function are linked Describe nucleic acids' structure and define the two types of nucleic acids Explain DNA's structure and role Explain RNA's structure and roles Biochemistry: The Chemical Composition of Living Matter Organic compounds are carbon containing covalently bonded compounds of the body, e.g. proteins and lipids. BIOLOGICAL MACROMOLECULES Four major classes of macromolecules 1. Carbohydrates 2. Lipids 3. Proteins 4. Nucleic Acids Macromolecules consist of individual subunits called monomers Monomers are linked together via covalent bonds into polymers CARBOHYDRATES Carbohydrates found in grains, fruits, and vegetables Provide energy to body in from of glucose Represented by the general formula (CH2O)n Ratio of Carbon:Hydrogen:Oxygen is 1:2:1 Three main subtypes: 1. Monosaccharides 2. Disaccharides Photo Credit:US 3. Polysaccharides Department of Agriculture Biochemistry: The Chemical Composition of Living Matter glucose Carbohydrates are organic compounds composed of carbon, hydrogen, and oxygen, with a general formula of CH2O. Simple sugars consisting of one single chain or ring structure are monosaccarhides. THREE STRUCTURAL ISOMERS OF A HEXOSE MONOSACCHARIDE Structural isomers/formula (C6H12O6) 1. Glucose – important source of energy 2. Galactose – part of lactose/milk sugar 3. Fructose - part of sucrose/fruit Biochemistry: The Chemical Composition of Living Matter sucrose Dissacharides are double sugars constructed of two monosaccharides by a synthesis reaction. Formation of a disaccharide Dehydration synthesis – two molecules of glucose are linked to form the disaccharide maltose A water molecule is formed as the two monosaccharides are linked by a covalent bond Hydrolysis – process of breaking polymers down into individual monomers – also known as a dehydration reaction Water serves as a reactant; one monomer receives a H+ and the other monomer receives an OH- In the dehydration reaction shown here - disaccharide maltose is broken down to form two glucose monomers Note that this reaction is the reverse of the synthesis reaction shown previous slide OTHER COMMON DISACCHARIDES Common disaccharides maltose (grain sugar) lactose (milk sugar) sucrose (table sugar) All are created via formation of covalent glycosidic linkages Biochemistry: The Chemical Composition of Living Matter Polysaccharides are long branching chains of simple sugars. Starch is a storage molecule for plants and glycogen is a storage molecule for animals POLYSACCHARIDES CAN BE DISTINGUISHED BY THEIR GLYCOSIDIC LINKAGES Starch is composed of Amylose and Amylopectin The monomers are joined in two linkage types 1. α 1-4 glycosidic bonds 2. α 1-6 glycosidic bonds Amylose = unbranched glucose monomers in α 1-4 glycosidic bonds Amylopectin = branched glucose monomers in α 1-4 and α 1-6 glycosidic bonds CELLUOSE – A POLYSACCHARIDE FOUND IN THE CELL WALL OF PLANTS Cellulose - glucose monomers are linked in unbranched chains by β 1-4 glycosidic linkages Every glucose monomer is flipped relative to the next one resulting in a linear, fibrous structure How Many sugar Groups are Present in a Disaccharide? A B C D Which one of these is difficult to digest and might be found in the structure of plants? A B C D Which one of these is found in animal cells? Biochemistry: The Chemical Composition of Living Matter Lipids are organic compounds formed of carbon and hydrogen atoms. Neutral fats or triglycerides are composed of fatty acid chains and glycerol. FATS WAXES AND OILS Glycerides are also linked linked to fatty acid chains with bonds. The main glycerol group has three Hydroxyls which can then bond, through dehydration synthesis, onto the long fatty acid chains. The number and complexity of the fatty acid chains will change the characteristic of the fat. SATURATED AND UNSATURATED FATTY ACIDS Stearic acid is a common saturated fatty acid. This means it contains no carbon-carbon double bonds in the carbon-backbone Pack tightly and exist as solids at room temperature (butter, fat in meats, etc) May be associated with cardiovascular disease – should be limited in your diet SATURATED AND UNSATURATED FATTY ACIDS Oleic acid is a common unsaturated fatty acid Contains at least one carbon-carbon double bond in carbon chain backbone Monounsaturated fat = one double bond Polyunsaturated fat = more than one double bond Most unsaturated fats are liquids at room temperature – referred to as oils WHAT’S THE DEAL WITH TRANS-FATS? Each double bond of an unsaturated fat may be in one of two positions Cis configuration – hydrogens on same side of chain Trans configuration – hydrogens on opposite side of chain Cis-acids have a kink in the chain They cannot be packed tightly Liquid at room temperature Trans-acids – no kink Can be created through processing Foods with trans fat may increase LDL cholesterol in humans (bad for heart Biochemistry: The Chemical Composition of Living Matter Saturated fats have carbon chains with single bonds, whereas unsaturated fats have carbon chains with at least one double bond. Below are two triglycerides, one with only single Carbon to Carbon bonds, and one with several double bonds. Which type of fat is known as “saturated” with Hydrogens? WAXES Long fatty acid chains esterified to long chain alcohols Hydrophobic and prevent water from sticking to surface Found on the feathers of some aquatic birds and on the surface of leaves from certain plants PHOSPHOLIPIDS Phospholipid - molecule with two fatty acids Modifiers attach to the phosphate group at the position and a modified phosphate group attached to labeled R a glycerol backbone The phosphate may be modified by the addition of charged or polar chemical groups Two common chemical groups that attach to phosphate are choline and serine PHOSPHOLIPIDS Biochemistry: The Chemical Composition of Living Matter Cholesterol plays has a role in membrane fluidity ○ Cold - Keeps the membrane from becoming too rigid or viscous by preventing the phospholipids from becoming too closely packed together ○ Heat - Keeps the membrane from becoming too “fluid” by having a higher heat tolerance and holding the phospholipids together Cholesterol helps to restrict the passage of molecules by increasing the packing of phospholipids, thus reducing permeability of the membrane. Biochemistry: The Chemical Composition of Living Matter Steroids are composed of hydrogen and carbon arranged in a ring structure. Steroids have two principal biological functions: as important components of cell membranes that alter membrane fluidity; and as signaling molecules. Cholesterol is the most common steroid and is the precursor to vitamin D, testosterone, estrogen, progesterone, aldosterone, cortisol, and bile salts. Why don’t lipids mix with water? The building blocks of proteins are amino acids which are composed of: a central carbon atom, a hydrogen atom, amine group, a carboxyl group, and a R-group. Biochemistry: The Chemical Composition of Living Matter A protein is a complex nitrogenous substance composed of a chain of amino acids. Each amino acid is connected by a peptide bond Amino acid chains less than 50 molecules long are polypeptides. Biochemistry: The Chemical Composition of Living Matter 2 types of proteins: fibrous or structural proteins (e.g. collagen) and globular or functional proteins (e.g. antibodies and enzymes). When the 3-D structure of globular proteins break apart they are denatured and nonfunctional. What is the monomer of a protein? Which structure is shown below? Biochemistry: The Chemical Composition of Living Matter What could cause a protein to “denature” or not function anymore? PROTEIN TYPES AND FUNCTIONS Type Example Functions Digestive enzymes Amylase, lipase, Help in digestion of food by catabolizing nutrients into pepsin, trypsin monomeric units Transport Hemoglobin, albumin Carry substances in the blood or lymph throughout the body Structural Actin, tubulin, keratin Construct different structures, like the cytoskeleton Hormones Insulin, thyroxine Coordinate the activity of different body systems Defense Immunoglobulins Protect the body from foreign pathogens Contractile Actin, myosin Effect muscle contraction Storage Legme storage proteins, Provide nourishment in early development of the embryo and Egg white (albumin) the seedling Identify the components of the cellular membrane Carbohydrate Glycogen Steroid Cholesterol Functional Protein Structural Protein Phospholipid Biochemistry: The Chemical Composition of Living Matter Nucleic acids are a class of organic compounds that include DNA and RNA. The building blocks of nucleic acids are nucleotides which are composed of a sugar, phosphate group, and a nitrogen base. Nucleotides have complementary base pairs: ○ Adenine and Thymine (uracil) ○ Guanine and Cytosine (Draw a T chart) Biochemistry: The Chemical Composition of Living Matter Pyrimidine Purine Biochemistry: The Chemical Composition of Living Matter A C T T C T A G G G A A C ? What are the T ? ? complementary ? A nucleotides for this T strand of DNA? G C Biochemistry: The Chemical Composition of Living Matter T C T A G G A A C T What are the T A complementary C G A nucleotides for this T strand of DNA? G C Biochemistry: The Chemical Composition of Living Matter DNA is a twisted double helix or staircase of 2 strands of nucleotides DNA has the nucleotide Thymine DNA provides the instructions for building every protein in the body DNA is transcribed into RNA DNA never leaves the nucleus of the cell Biochemistry: The Chemical Composition of Living Matter RNA is composed of one strand of nucleotides RNA had nucleotide Uracil RNA exists in 3 main varieties: messenger, transfer, and ribosomal RNA. (11 total types, micro, fragmented etc.) RNA carries out the orders for protein synthesis which is called Translation Biochemistry: The Chemical Composition of Living Matter DNA (Deoxyribose Nucleic Acid) RNA (Ribonucleic Acid) provides the instructions for building carries out the orders for protein every protein in the body synthesis Double Helix Single strand Nucleic acids GCTA Nucleic acids GCUA Can leave the nucleus and Exist as 3 Never leave nucleus types, mRNA tRNA and ribosomal Like carrying copies of one page Like having all blueprints filed at city hall instructions with you to different construction sites within the city List one difference between DNA and RNA I feel pretty confident in my knowledge, and would be I think I will get it after studying my notes and I don’t get it and I might need to ask for help or get Knowledge Check! able to explain it to a peer. taking the practice quiz. tutoring from the SI leader. Drag the Light Bulb to the area which best matches how you feel about today’s lesson! This will help me make adjustments to next week’s content. Thank you! Chapter Assignments Chapter Homework Chapter Laboratory Chapter Quiz Write up Learn the concepts of the Check for comprehension of chapter through guided Face to Face or Online with Concepts activities Video Guide Check Out These Study Resources! Further Readin g a mes s e d g ab ul ar y ba Voc ar d s fl ashc r n i ng o r c ol o r i ng e d Art lea c u rat c ia lly S p e Group Discussion 1. Click one of the following links a. Read the article, watch the video or complete the activity 2. Discuss your observations with your team a. What did you learn? Which part was most interesting? 3. Post a FlipGrid before the time runs out a. Use your own experiences to personalize your post

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