Biological Macromolecules Notes PDF

© Getting Down with Science Carbohydrates © Getting Down with Science  Carbohydrates Includes sugars and polymers of sugars Contain a carbonyl group and many hydroxyl groups Comprised of C, H, and O Monosaccharides: simple sugars Molecular formulas with multiples of the u...

© Getting Down with Science Carbohydrates © Getting Down with Science  Carbohydrates Includes sugars and polymers of sugars Contain a carbonyl group and many hydroxyl groups Comprised of C, H, and O Monosaccharides: simple sugars Molecular formulas with multiples of the unit CH2O Most common is glucose ○ Nutrients and fuel for cells Used in cellular respiration Can serve as building blocks for amino acids, or as monomers for di- and polysaccharides © Getting Down with Science  Carbohydrates Disaccharides: two monosaccharides joined together by covalent bonds Most common is sucrose ○ Monomers of sucrose: glucose and fructose ○ Plants transfer carbohydrates from roots to leaves in the form of sucrose © Getting Down with Science  Carbohydrates Polysaccharides: polymer with many sugars joined via dehydration reactions Storage polysaccharides Plants store starch (polymer of glucose monomers) ○ Allows plants to store excess glucose Animals store glycogen (polymer of glucose) ○ Stored in liver and muscle cells Structural polysaccharides Cellulose: tough substance that forms plant cell walls Chitin: forms exoskeleton of arthropods © Getting Down with Science  Practice 1. You are given an unknown monosaccharide to identify in the lab. The only clue you are given is that it has 4 carbons. You (being an excellent AP bio student) figure out the formula. What is the unknown monosaccharide? Answer: C4H8O4, Threose © Getting Down with Science Proteins © Getting Down with Science  Formation of a Protein Amino acid Peptide Polypeptide Protein small large © Getting Down with Science  Proteins Protein: molecule consisting of polypeptides (polymers of amino acids) folded into a 3D shape Comprised of C, H, O, N, and S Shape determines function © Getting Down with Science  Amino Acids Molecules that have an amino group and a carboxyl group 20 different amino acids General Structure R = variable side chain Amino group carboxyl group Unique side chain (R) © Getting Down with Science  Amino Acids Each amino acid (AA) has a unique side chain ○ Unique aspects of the AA are based on the side chain’s physical and chemical properties ○ Side chains can be grouped as: Nonpolar (hydrophobic) Polar (hydrophilic) Charged/ionic (hydrophilic) ○ Side chains interact, which determine the shape and function of the protein © Getting Down with Science  Formation of Peptide Bonds To form a peptide bond the carboxyl group of one AA must be positioned next to the amino group of another AA Dehydration reaction Repetitive backbone Side chains Peptide bond © Getting Down with Science  Polypeptides Polypeptides: many AA linked by peptide bonds Each polypeptide has a unique sequence of AAs and directionality Each end is chemically unique ○ One end is a free amino group (N-terminus) ○ One end is a free carboxyl group (C-terminus) © Getting Down with Science  Polypeptides The sequence of AAs determines the 3D shape Remember: SHAPE determines FUNCTION ○ When a polypeptide twists and folds (because of R group interaction) it forms a protein Quick! Think, pair share How is the unique sequence of AAs determined for a Genes polypeptide? © Getting Down with Science  Functions of Proteins Function of proteins include: ○ Antibody-help protect the body from disease ○ Enzyme- carry out chemical reactions or assist in creating new molecules ○ Messenger- transmit signals (ie hormones) ○ Structural- provide structure and support ○ Transport/storage- bind to and carry small atoms and molecules through the body © Getting Down with Science  Levels of Protein Structure Primary Secondary Linear chain of AA Coils and folds due to Determined via genes hydrogen bonding Dictates secondary and within the polypeptide tertiary forms backbone 𝛃 pleated sheet- hydrogen bonds between polypeptide chains lying side by side 𝛂 helix- hydrogen bonding between every 4th AA © Getting Down with Science  Levels of Protein Structure Tertiary Quaternary 3D folding due to interactions Association of two or between the side chains of the more polypeptides AAs Found in only some Reinforced by hydrophobic proteins interactions and disulfide bridges of the side chains ○ The covalent bond formed between sulfur atoms of two cysteine monomers All four levels of a protein’s structure determine the protein’s function © Getting Down with Science  Practice Let’s work on the practice problems! © Getting Down with Science  Practice 1. Cystic fibrosis is a serious, life-threatening disease that affects the lungs and digestive system of affected individuals. This disease results from the deletion of three nucleotides on the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene. This gene codes for a transmembrane protein that regulates ion channels in epithelial tissue. Provide an explanation for how this deletion could result in cystic fibrosis. © Getting Down with Science Nucleic Acids Topic 6 © Getting Down with Science  Nucleic Acids Nucleic acids: polymers made of nucleotide monomers Function to: Store, transmit and express hereditary information Two forms: 1. Deoxyribonucleic acid (DNA) 2. Ribonucleic acid (RNA) © Getting Down with Science Components of Nucleic Acids Nucleotides Polynucleotides Nucleic Acids © Getting Down with Science  Nucleotides Contain 3 parts: 1. Nitrogenous base 2. Five carbon sugar (pentose) 3. Phosphate group(s) In polynucleotides each monomer only has one phosphate group © Getting Down with Science  Nitrogenous Base Two types: pyrimidines and purines Pyrimidines: one ring with 6 atoms Cytosine Thymine Only found in DNA Uracil Only found in RNA Purines: one ring with 6 atoms bonded to one ring with 5 atoms Adenine Guanine © Getting Down with Science  Five Carbon Sugar A sugar is bonded to the base In DNA the sugar is deoxyribose Differ in structure and function In RNA the sugar is ribose Deoxyribose Ribose © Getting Down with Science  Phosphate Group A phosphate group is added to the 5’ carbon of the sugar (which is attached to the base) to form a Nucleoside- portion without phosphate group nucleotide 5’ carbon 5’ carbon © Getting Down with Science  Polynucleotides Nitrogenous Phosphate groups link adjacent nucleotides bases Phosphodiester linkage Directionality 5’ phosphate end ○ 5’ to 3’ The sequence of bases along the DNA or mRNA is unique for each gene Dictates AA sequence Sugar ○ Dictates primary phosphate structure of a protein backbone Dictates 3D structure of a 3’ hydroxyl protein end © Getting Down with Science  DNA Consists of two polynucleotides Forms a double helix ○ Strands are antiparallel ○ Held together by hydrogen bonds between bases antiparallel Cytosine binds to guanine Adenine binds to thymine © Getting Down with Science  RNA Single stranded polynucleotide Variable in shape ○ Due to base pairing within RNA Adenine bonds to uracil Cytosine bonds to guanine © Getting Down with Science  Practice 1. You are given a segment of DNA: ○ 5’- CATGTCAAC-3’ What is the complimentary strand? Answer: 3’-GTACAGTTG-5’ © Getting Down with Science  Practice Let’s work on the practice problems! © Getting Down with Science Lipids © Getting Down with Science  Lipids Lipids: class of molecules that do not include true polymers Generally small in size ○ Often not considered to be a macromolecule Lipids are nonpolar-hydrophobic Types of lipids: 1. Fats 2. Phospholipids 3. Steroids © Getting Down with Science  Fats Fats are composed of glycerol and fatty acids Glycerol: classified as an alcohol (hydroxyl groups) Fatty acids: long carbon chains (carboxyl group at one end) 3 fatty acids join to a glycerol via ester linkage ○ Bond between a hydroxyl and carboxyl group Classified as a saturated fatty acid or an unsaturated fatty acid ○ Saturated fatty acid: no double bonds between carbons in the carbon chain = more hydrogen (think: saturated with hydrogen) ○ Unsaturated fatty acid: contains one or more double bonds © Getting Down with Science  Phospholipids Major component of cell membranes Two fatty acids attached to a glycerol and a phosphate Assemble as a bilayer in H2O Tails are hydrophobic Head is hydrophilic © Getting Down with Science  Steroids Lipids that have four fused rings Unique groups attached to the ring determine the type of steroid Example: testosterone © Getting Down with Science  Putting it all together Fill out this chart with the appropriate responses monosaccharide Carbohydrates Carbon, hydrogen, Polysaccharide oxygen Carbon, hydrogen, Proteins oxygen, nitrogen, Amino acids Polypeptides sulfur Carbon, hydrogen, oxygen (phosphorus Glycerol and Does not contain Lipids fatty acids true polymers for phospholipids) Carbon, hydrogen, Nucleic Acids oxygen, nitrogen, Nucleotides DNA, RNA phosphorus © Getting Down with Science