Macromolecules: The Building Blocks of Life PDF

Created by Turbolearn AI 🌿 Macromolecules: The Building Blocks of Life Macromolecules are large biological molecules that are composed of many smaller molecules called monomers. These monomers are linked together through chemical bonds to form a long chain...

Created by Turbolearn AI 🌿 Macromolecules: The Building Blocks of Life Macromolecules are large biological molecules that are composed of many smaller molecules called monomers. These monomers are linked together through chemical bonds to form a long chain. Definition of a Macromolecule A macromolecule is a large molecule that is composed of many smaller molecules called monomers. Types of Macromolecules Carbohydrates Proteins Nucleic acids Lipids 🍞 Carbohydrates Carbohydrates are a type of macromolecule that serves as a source of energy and building material for cells. Definition of a Carbohydrate A carbohydrate is a type of macromolecule that is composed of carbon, hydrogen, and oxygen atoms. Types of Carbohydrates Monosaccharides (simple sugars) Disaccharides (two monosaccharides linked together) Polysaccharides (many monosaccharides linked together) Monosaccharides Monosaccharide Molecular Formula Glucose C6H12O6 Fructose C6H12O6 Galactose C6H12O6 Polysaccharides Polysaccharide Function Starch Energy storage in plants Glycogen Energy storage in animals Cellulose Structural component of plant cell walls 💧 Lipids Page 1  Created by Turbolearn AI Lipids are a type of macromolecule that is characterized by their hydrophobic (water-repelling) properties. Definition of a Lipid A lipid is a type of macromolecule that is characterized by its hydrophobic properties. Types of Lipids Fats Phospholipids Steroids Fats Type of Fat Description Saturated fat Solid at room temperature, found in animal products Unsaturated fat Liquid at room temperature, found in plant products 🧬 Proteins Proteins are a type of macromolecule that is composed of amino acids. Definition of a Protein A protein is a type of macromolecule that is composed of amino acids. Structure of Proteins Primary structure: sequence of amino acids Secondary structure: coils and folds in the polypeptide chain Tertiary structure: overall shape of the protein Quaternary structure: arrangement of multiple polypeptide chains Functions of Proteins Enzymes: speed up chemical reactions Defense: protect against pathogens Storage: store energy and nutrients Transport: transport molecules across cell membranes Communication: transmit signals between cells 🧬 Nucleic Acids Nucleic acids are a type of macromolecule that stores and transmits genetic information. Definition of a Nucleic Acid A nucleic acid is a type of macromolecule that stores and transmits genetic information. Types of Nucleic Acids DNA (deoxyribonucleic acid) Page 2  Created by Turbolearn AI RNA (ribonucleic acid) Structure of DNA Double helix structure Sugar-phosphate backbone Nitrogenous bases: adenine (A), guanine (G), cytosine (C), and thymine (T) Base Pairing Adenine (A) pairs with thymine (T) Guanine (G) pairs with cytosine (C) 🧬 Genomics and Proteomics Genomics and proteomics are the study of the structure, function, and evolution of genomes and proteomes. Definition of Genomics Genomics is the study of the structure, function, and evolution of genomes. Definition of Proteomics Proteomics is the study of the structure, function, and evolution of proteomes. Applications of Genomics and Proteomics Personalized medicine Gene therapy Synthetic biology Forensic analysis## Macromolecules 🧬 Macromolecules are large biological molecules that are composed of smaller molecules called monomers. There are four main types of macromolecules: carbohydrates, proteins, nucleic acids, and lipids. What are Macromolecules? 🤔 A macromolecule is a large molecule that is composed of many smaller molecules called monomers. Macromolecules are typically found in living organisms and play a crucial role in many biological processes. Types of Macromolecules 📚 Type of Description Macromolecule Carbohydrates Serve as a source of energy and provide structural support Have a wide range of functions, including catalyzing reactions and Proteins transporting substrates Nucleic Acids Store genetic information and function in gene expression Lipids A diverse group of hydrophobic molecules that do not mix well with Page 3  Created by Turbolearn AI water Monomers and Polymers 🔗 Monomers: Small molecules that serve as the building blocks of polymers Polymers: Long molecules consisting of many similar or identical building blocks linked by covalent bonds Synthesis and Breakdown of Polymers 🔬 Polymerization: The process by which cells make polymers Hydrolysis: The process by which cells break down polymers Dehydration Reaction: A reaction in which two molecules are covalently bonded to each other with the loss of a small molecule, such as water Key Concepts 📝 Macromolecules are polymers, built from monomers Carbohydrates serve as fuel and building material Lipids are a diverse group of hydrophobic molecules Proteins include a diversity of structures, resulting in a wide range of functions Nucleic acids store, transmit, and help express hereditary information Functional Groups 🎯 Functional groups are specific groups of atoms within a molecule that determine its chemical properties. Types of Functional Groups 🔍 Type of Functional Group Description Amino Group A group that can accept H+ from the surrounding solution Carboxyl Group A group that can donate H+ to the surrounding solution Hydroxyl Group A group that can form hydrogen bonds with other molecules Properties of Functional Groups 🔑 Acidic: Can donate H+ to the surrounding solution Basic: Can accept H+ from the surrounding solution Polar: Can form hydrogen bonds with other molecules Nucleic Acids 🧬 Nucleic acids are macromolecules that store genetic information and function in gene expression. Structure of Nucleic Acids 🔍 DNA (Deoxyribonucleic Acid): A double-stranded helix composed of nucleotides RNA (Ribonucleic Acid): A single-stranded molecule composed of nucleotides Components of Nucleic Acids 🔗 Nucleotides: The building blocks of nucleic acids, composed of a sugar molecule, a phosphate group, and a nitrogenous base Page 4  Created by Turbolearn AI Nitrogenous Bases: The components of nucleotides that determine the genetic information stored in nucleic acids Functions of Nucleic Acids 📝 Store Genetic Information: Nucleic acids store the genetic information necessary for the development and function of living organisms Function in Gene Expression: Nucleic acids play a crucial role in the process of gene expression, which involves the translation of genetic information into proteins.## 🍞️The Diversity of Polymers A cell has thousands of different macromolecules; the collection varies from one type of cell to another. The inherited differences between close relatives, such as human siblings, reflect small variations in polymers, particularly DNA and proteins. Molecular differences between unrelated individuals are more extensive, and those between species greater still. The Basis for Diversity in Life's Polymers The key to the diversity of macromolecules is the arrangement of their monomers, not the number of different types of monomers. Building a huge variety of polymers from a limited number of monomers is analogous to constructing hundreds of thousands of words from only 26 letters of the alphabet. However, this analogy falls far short of describing the great diversity of macromolecules because most biological polymers have many more monomers than the number of letters in even the longest word. The Four Main Classes of Large Biological Molecules Class Description Carbohydrates Serve as fuel and building material Perform a wide range of functions, including structural, enzymatic, and Proteins transport roles Contain genetic information and play a central role in the transmission of Nucleic Acids genetic traits Serve as energy storage molecules and play a key role in cell membrane Lipids structure Hydrolysis and Dehydration Reactions Hydrolysis is a chemical reaction in which a molecule is cleaved into two parts using water. This reaction is often used to break down polymers into their monomers. Hydrolysis: a chemical reaction in which a molecule is cleaved into two parts using water. Dehydration reactions, on the other hand, are used to form polymers from monomers. Dehydration Reaction: a chemical reaction in which two molecules combine to form a larger molecule, releasing water in the process. 🍮️Carbohydrates Page 5  Created by Turbolearn AI Carbohydrates include sugars and polymers of sugars. The simplest carbohydrates are the monosaccharides, or simple sugars. Classification of Monosaccharides Monosaccharides can be classified based on the number of carbons in their molecular formula, the location of the carbonyl group, and the spatial arrangement of their parts around asymmetric carbons. Classification Description Triose A sugar with three carbons (e.g. glyceraldehyde, dihydroxyacetone) Pentose A sugar with five carbons (e.g. ribose, ribulose) Hexose A sugar with six carbons (e.g. glucose, galactose, fructose) A sugar with a carbonyl group at the end of the chain (e.g. glyceraldehyde, Aldose glucose) A sugar with a carbonyl group within the chain (e.g. dihydroxyacetone, Ketose fructose) Structure of Glucose Glucose is a hexose with a molecular formula of C6H12O6. It has a carbonyl group at the end of the chain, making it an aldose. Ring Structure of Glucose In aqueous solutions, glucose molecules form rings, which are the most stable form of the sugar under physiological conditions. 🍞️Disaccharides A disaccharide consists of two monosaccharides joined by a glycosidic linkage, a covalent bond formed between two monosaccharides by a dehydration reaction. Disaccharide Monosaccharides Maltose Glucose + Glucose Sucrose Glucose + Fructose Lactose Glucose + Galactose Disaccharides are sugars composed of two monosaccharides joined by a glycosidic linkage. Examples of Disaccharides Sucrose (table sugar): a glucose molecule joined to a fructose molecule Lactose (milk sugar): a glucose molecule joined to a galactose molecule Maltose: a glucose molecule joined to another glucose molecule Structure of Disaccharides Page 6  Created by Turbolearn AI A disaccharide is formed when two monosaccharides are joined by a glycosidic linkage, resulting in the loss of a water molecule. Importance of Disaccharides Disaccharides must be broken down into monosaccharides to be used for energy by organisms. Lactose intolerance is a common condition in humans who lack lactase, the enzyme that breaks down lactose. Polysaccharides 🌾 Polysaccharides are macromolecules composed of many monosaccharides joined by glycosidic linkages. Types of Polysaccharides Storage Polysaccharides: used to store energy in plants and animals Structural Polysaccharides: used to build strong materials in plants and animals Storage Polysaccharides Polysaccharide Source Structure Starch Plants Unbranched or branched chain of glucose monomers Glycogen Animals Branched chain of glucose monomers Structural Polysaccharides Polysaccharide Source Structure Cellulose Plants Unbranched chain of glucose monomers with β-1,4 linkages Chitin Arthropods Chain of glucose monomers with β-1,4 linkages Importance of Polysaccharides Polysaccharides play a crucial role in storing energy and building strong materials in plants and animals. Cellulose is the most abundant organic compound on Earth and is used to make paper and cotton. Chitin is used by arthropods to build their exoskeletons. Digestion of Polysaccharides Enzymes that digest starch are unable to digest cellulose due to the different shapes of these two molecules. Few organisms possess enzymes that can digest cellulose, but some microorganisms and fungi can break down cellulose into glucose monomers.## Lipids 🧬 Lipids are a diverse group of hydrophobic molecules that do not include true polymers and are generally not big enough to be considered macromolecules. Definition of Lipids Page 7  Created by Turbolearn AI Lipids are a class of biological molecules that are hydrophobic, meaning they mix poorly, if at all, with water. This behavior is based on their molecular structure, which consists mostly of hydrocarbon regions with relatively nonpolar CH bonds. Types of Lipids Fats Phospholipids Steroids Waxes Pigments Fats Fats are large molecules assembled from smaller molecules by dehydration reactions. A fat consists of a glycerol molecule joined to three fatty acids. Structure of a Fat Molecule Component Description Glycerol A three-carbon alcohol with one hydroxyl group on each carbon Fatty Acid A long carbon chain with a carboxyl group at one end Ester Linkage A bond between a hydroxyl group and a carboxyl group Synthesis of a Fat Molecule A fat molecule is formed when a dehydration reaction occurs between each of the three hydroxyl groups on the glycerol molecule and a total of three fatty acid molecules. Saturated and Unsaturated Fats Saturated Fats: Fats made from saturated fatty acids, which have no double bonds between carbon atoms. Examples include lard and butter. Unsaturated Fats: Fats made from unsaturated fatty acids, which have one or more double bonds between carbon atoms. Examples include olive oil and cod liver oil. Comparison of Saturated and Unsaturated Fats Saturated Fats Unsaturated Fats Double No double bonds One or more double bonds Bonds Hydrogen As many hydrogen atoms as possible One fewer hydrogen atom on each Atoms are bonded to the carbon skeleton double-bonded carbon Physical Solid at room temperature Liquid at room temperature State Examples Lard, butter Olive oil, cod liver oil Functions of Fats Page 8  Created by Turbolearn AI Energy Storage: Fats are an important source of energy for the body. A gram of fat stores more than twice as much energy as a gram of a polysaccharide, such as starch. Other Functions: Fats also have other functions, such as providing insulation and protecting organs.## Lipids and Their Functions 🌿 Adipose Tissue and Energy Storage Adipose tissue is a type of connective tissue that stores energy in the form of fat. In humans and other mammals, adipose cells (also known as fat cells) swell and shrink as fat is deposited and withdrawn from storage. Adipose tissue also cushions vital organs, such as the kidneys, and a layer of fat beneath the skin insulates the body. Phospholipids 🌊 Phospholipids are a type of lipid that are essential for cells because they are major constituents of cell membranes. Their structure provides a classic example of how form fits function at the molecular level. A phospholipid is a molecule that has a hydrophilic (polar) head and two hydrophobic (nonpolar) tails. The structure of a phospholipid consists of: A glycerol molecule attached to two fatty acid tails (hydrophobic chains of carbon and hydrogen) A phosphate group attached to the third hydroxyl group of glycerol A charged or polar molecule attached to the phosphate group (such as choline) The phospholipid bilayer forms a boundary between the cell and its external environment and establishes separate compartments within eukaryotic cells. Steroids 💊 Steroids are lipids characterized by a carbon skeleton consisting of four fused rings. Different steroids are distinguished by the particular chemical groups attached to this ensemble of rings. Cholesterol is a type of steroid that is a crucial molecule in animals. It is a common component of animal cell membranes and is also the precursor from which other steroids, such as the vertebrate sex hormones, are synthesized. Comparison of Fats and Phospholipids Fats (Triglycerides) Phospholipids Two fatty acid tails attached to glycerol, with a Three fatty acid tails Structure phosphate group attached to the third hydroxyl attached to glycerol group Function Energy storage Cell membrane component Amphipathic (hydrophilic head and hydrophobic Properties Hydrophobic tails) Proteins and Their Functions 🧬 Page 9  Created by Turbolearn AI Overview of Protein Functions Proteins are biologically functional molecules made up of one or more polypeptides, each folded and coiled into a specific three-dimensional structure. They account for more than 50% of the dry mass of most cells and are instrumental in almost everything organisms do. Storage proteins: store amino acids (e.g. casein, ovalbumin) Hormonal proteins: coordinate an organism's activities (e.g. insulin) Contractile and motor proteins: movement (e.g. actin, myosin) Defensive proteins: protection against disease (e.g. antibodies) Transport proteins: transport substances (e.g. hemoglobin) Enzymatic proteins: regulate metabolism by acting as catalysts Amino Acids (Monomers) Amino acids are the building blocks of proteins. They share a common structure, with an amino group and a carboxyl group attached to a central carbon atom (the alpha carbon). An amino acid is an organic molecule with both an amino group and a carboxyl group. The 20 amino acids that cells use to build their thousands of proteins can be grouped according to the properties of their side chains: Nonpolar amino acids: hydrophobic side chains Polar amino acids: hydrophilic side chains Acidic amino acids: negatively charged side chains Amino Acid Side Chain Properties Alanine Nonpolar Hydrophobic Serine Polar Hydrophilic Aspartic acid Acidic Negatively charged Note: The amino acids are listed in the order they appear in Figure 5.14.## Amino Acid Structure and Properties 🧬 Amino acids are the building blocks of proteins. They have a general structure, which includes a central carbon atom (alpha carbon) bonded to an amino group, a carboxyl group, a hydrogen atom, and a side chain (R group). Amino Acid Classification Amino acids can be classified into several groups based on the properties of their side chains. Nonpolar (Hydrophobic) Side Chains: These amino acids have side chains that are nonpolar and hydrophobic, meaning they do not have a charge and tend to avoid water. Glycine (Gly or G): R = single bond H Alanine (Ala or A): R = single bond CH₃ (methyl) Valine (Val or V): R = single bond CH(CH₃)₂ (isopropyl) Leucine (Leu or L): R = single bond CH₂CH(CH₃)₂ (isobutyl) Isoleucine (Ile or I): R = single bond CH(CH₃)CH₂CH₃ (sec-butyl) Methionine (Met or M): R = single bond CH₂CH₂SCH₃ Phenylalanine (Phe or F): R = single bond CH₂C₆H₅ (benzyl) Page 10  Created by Turbolearn AI Tryptophan (Trp or W): R = single bond CH₂C₈H₆N (indole) Polypeptide Structure A polypeptide is a chain of amino acids linked together by peptide bonds. The polypeptide backbone consists of a series of amino acids held together with peptide bonds. Component Description Amino end (N- The left end of the polypeptide chain, where the amino group is located terminus) Carboxyl end (C- The right end of the polypeptide chain, where the carboxyl group is terminus) located A covalent bond between the carboxyl group of one amino acid and the Peptide bond amino group of the next Protein Structure and Function A protein is a functional molecule composed of one or more polypeptide chains. The specific activities of proteins result from their intricate three-dimensional architecture. "The specific activities of proteins result from their intricate three-dimensional architecture, the simplest level of which is the sequence of their amino acids." The sequence of amino acids determines the three-dimensional structure of a protein, which in turn determines its function. Visualizing Proteins Proteins can be represented in different ways, depending on the goal of the illustration. Space-filling model: Shows all the atoms of the protein, emphasizing the overall globular shape. Ribbon model: Shows only the backbone of the polypeptide, emphasizing how it folds and coils to form a 3-D shape. Wireframe model: Shows the backbone of the polypeptide chain with side chains (R groups) extending from it. Protein Function A protein's specific structure determines how it works. In almost every case, the function of a protein depends on its ability to recognize and bind to some other molecule. "A protein's specific structure determines how it works. In almost every case, the function of a protein depends on its ability to recognize and bind to some other molecule." Examples of protein function include: Antibodies binding to specific foreign substances Enzymes binding to specific substrates Receptor proteins binding to specific ligands## Protein Structure and Function 🧬 The Relationship Between Structure and Function Page 11  Created by Turbolearn AI In biology, the structure of an object reflects its function. This theme is evident in the relationship between protein structure and function. Proteins are complex molecules that perform a wide range of functions in living organisms. Four Levels of Protein Structure Proteins have four levels of structure: primary, secondary, tertiary, and quaternary. Level Description Primary Structure The sequence of amino acids in a protein Secondary Regions stabilized by hydrogen bonds between atoms of the Structure polypeptide backbone Tertiary Structure The overall 3D shape of a protein Quaternary The arrangement of multiple polypeptide chains in a protein Structure Primary Structure The primary structure of a protein is its sequence of amino acids. This sequence is determined by the genetic information encoded in the DNA of an organism. For example, the primary structure of the protein transthyretin is composed of 127 amino acids. The sequence of these amino acids determines the protein's secondary and tertiary structure. Secondary Structure The secondary structure of a protein is the arrangement of its polypeptide backbone in space. This structure is stabilized by hydrogen bonds between atoms of the backbone. There are two main types of secondary structure: Alpha Helices: A spiral structure formed by hydrogen bonds between the backbone atoms Beta Pleated Sheets: A flat structure formed by hydrogen bonds between the backbone atoms Tertiary Structure The tertiary structure of a protein is its overall 3D shape. This structure is determined by the interactions between the amino acids in the protein. The tertiary structure of a protein is stabilized by: Hydrogen Bonds: Weak bonds between atoms of the polypeptide backbone Ionic Bonds: Electrostatic interactions between positively and negatively charged amino acids Disulfide Bridges: Covalent bonds between cysteine amino acids Quaternary Structure The quaternary structure of a protein is the arrangement of multiple polypeptide chains in a protein. Page 12  Created by Turbolearn AI For example, the protein hemoglobin is composed of four polypeptide chains that work together to transport oxygen in the blood. Protein Folding Protein folding is the process by which a protein assumes its native 3D structure. This process is influenced by the protein's primary structure and the physical and chemical conditions of its environment. Protein folding is a complex process that involves the formation of intermediate structures before the protein assumes its native shape. Denaturation and Renaturation Denaturation is the process by which a protein loses its native shape and becomes biologically inactive. Denaturation can be caused by: High Temperatures: Excessive heat can disrupt the weak bonds that stabilize a protein's structure Chemical Treatments: Certain chemicals can disrupt the hydrogen bonds and ionic bonds that stabilize a protein's structure Renaturation is the process by which a denatured protein returns to its native shape. Renaturation can occur when the denaturing agent is removed and the protein is returned to its normal environment. Determining Protein Structure There are several methods used to determine the 3D structure of a protein, including: X-Ray Crystallography: A technique that uses X-rays to determine the 3D structure of a protein Nuclear Magnetic Resonance (NMR) Spectroscopy: A technique that uses magnetic fields and radio waves to determine the 3D structure of a protein Cryo-Electron Microscopy (Cryo-EM): A technique that uses electron microscopy to determine the 3D structure of a protein Bioinformatics: A field of study that uses computational methods to analyze and predict protein structure and function## X-Ray Crystallography 📸 X-ray crystallography is a technique used to determine the three-dimensional structure of macromolecules such as nucleic acids and proteins. The Process Researchers aim an X-ray beam through crystalized protein or nucleic acid. The atoms of the crystal diffract (bend) the X-rays into an orderly array that a digital detector records as a pattern of spots called an X-ray diffraction pattern. Using data from X-ray diffraction patterns and the sequence of monomers determined by chemical methods, researchers can build a 3-D computer model of the macromolecule being studied. Intrinsically Disordered Proteins 🌀 Page 13  Created by Turbolearn AI Intrinsically disordered proteins are proteins that do not have a distinct 3-D structure until they interact with a target protein or other molecule. These proteins may account for 20-30% of mammalian proteins. Their flexibility and indefinite structure are important for their function, which may require binding with different targets at different times. Nucleic Acids 🧬 Nucleic acids are polymers made of monomers called nucleotides. They store, transmit, and help express hereditary information. The Roles of Nucleic Acids DNA (deoxyribonucleic acid) provides directions for its own replication and directs RNA synthesis and protein synthesis. RNA (ribonucleic acid) conveys genetic instructions for building proteins from the nucleus to the cytoplasm. Gene Expression 🔄 Gene expression is the process by which the information encoded in a gene is converted into a functional product, such as a protein. The flow of genetic information is: DNA → RNA → protein The sites of protein synthesis are cellular structures called ribosomes. The Components of Nucleic Acids 🔍 Nucleotides A nucleotide is composed of three parts: A five-carbon sugar (pentose) A nitrogen-containing (nitrogenous) base One to three phosphate groups Nucleotide Component Description Sugar Five-carbon sugar (deoxyribose in DNA, ribose in RNA) Nitrogenous Base Pyrimidines (cytosine, thymine, uracil) or purines (adenine, guanine) Phosphate Group Attached to the 5' carbon of the sugar Nucleosides A nucleoside is the sugar plus nitrogenous base without the phosphate group. Polynucleotides A polynucleotide is a polymer of nucleotides linked together by phosphodiester bonds. Polynucleotide Component Description Sugar-Phosphate Backbone Repeating pattern of sugar-phosphate units Page 14  Created by Turbolearn AI Nitrogenous Bases Attached to the sugar-phosphate backbone 5' End Phosphate group attached to the 5' carbon 3' End Hydroxyl group on the 3' carbon The Structure of DNA and RNA Molecules 🌀 DNA Structure A DNA molecule has two polynucleotides, or strands, that wind around an imaginary axis, forming a double helix. The two sugar-phosphate backbones run in opposite 5' → 3' directions from each other (antiparallel). The sugar-phosphate backbones are on the outside of the helix, and the nitrogenous bases are paired in the interior of the helix. RNA Structure RNA molecules are typically single-stranded and have a more flexible structure than DNA.## DNA Structure 🧬 The DNA molecule is usually a double helix, with the sugar-phosphate backbones of the antiparallel polynucleotide strands on the outside of the helix. Hydrogen bonds between pairs of nitrogenous bases hold the two strands together. Base Pairing In base pairing, only certain bases in the double helix are compatible with each other. Adenine (A) always pairs with Thymine (T) Guanine (G) always pairs with Cytosine (C) "Base pairing is the process by which nitrogenous bases in DNA pair with each other to form a double helix structure." Complementary Strands The two strands of the double helix are complementary, each the predictable counterpart of the other. This feature of DNA makes it possible to generate two identical copies of each DNA molecule in a cell that is preparing to divide. Base Sequence Complementary Strand 5'-AGGTCCG-3' 3'-TCCAGGC-5' RNA Structure 🧬 RNA molecules, by contrast, exist as single strands. Complementary base pairing can occur, however, between regions of two RNA molecules or even between two stretches of nucleotides in the same RNA molecule. Transfer RNA (tRNA) Page 15  Created by Turbolearn AI A tRNA molecule is about 80 nucleotides in length. Its functional shape results from base pairing between nucleotides where complementary stretches of the molecule can run antiparallel to each other. In RNA, Adenine (A) pairs with Uracil (U) Thymine (T) is not present in RNA Genomics and Proteomics 🧬 The study of large sets of genes or even comparing whole genomes of different species is called genomics. A similar analysis of large sets of proteins, including their sequences, is called proteomics. Contributions of Genomics and Proteomics to Biology Evolution: Genome sequence comparisons have identified the hippopotamus as the land mammal sharing the most recent common ancestor with whales. Medicine: Genomics and proteomics have advanced our understanding of the genetic basis of diseases and the development of new treatments. Field of Biology Contribution of Genomics and Proteomics Evolution Understanding relationships among species Medicine Understanding the genetic basis of diseases Ecology Understanding the impact of environmental changes on ecosystems DNA and Proteins as Tape Measures of Evolution 🧬 DNA and proteins can be used to measure the evolutionary relationships between different species. Siblings have greater similarity in their DNA and proteins than do unrelated individuals of the same species. Species that appear to be closely related based on anatomical evidence also share a greater proportion of their DNA and protein sequences. Species Number of Amino Acid Differences Human and Gorilla 1 Human and Frog 67 Molecular genealogy is the study of the relationships between organisms based on their DNA and protein sequences. This concept is based on the idea that organisms that are closely related will have more similar DNA and protein sequences than those that are more distantly related. Comparing DNA and Protein Sequences When comparing DNA and protein sequences, scientists look for similarities and differences between the sequences. The more similar the sequences, the more closely related the organisms are likely to be. Example: Human and Chimpanzee Genomes Page 16  Created by Turbolearn AI The human genome is 98.8% identical to that of the chimpanzee, but only roughly 85% identical to that of the mouse, a more distant evolutionary relative. This suggests that humans and chimpanzees are more closely related than humans and mice. Example: Hemoglobin Polypeptide Chain The polypeptide chain of human hemoglobin differs from that of the gorilla by only 1 amino acid, while it differs from that of the frog by 67 amino acids. This suggests that humans and gorillas are more closely related than humans and frogs. Analyzing Polypeptide Sequence Data 🧬 Rhesus Monkeys or Gibbons: Which is More Closely Related to Humans? To determine which of these two species is more closely related to humans, we can compare the amino acid sequence of the polypeptide chain of hemoglobin. Species Amino Acid Sequence VHLTPEEKSAVTALWGKVNVDEVGGEALGRLLVVYPWTQR Human FFESFGDLST Rhesus VHLTPEEKNAVTTLWGKVNVDEVGGEALGRLLLVYPWTQR Monkey FFESFGDLSS VHLTPEEKSAVTALWGKVNVDEVGGEALGRLLVVYPWTQR Gibbon FFESFGDLST Interpreting the Data The amino acid sequence of the human and gibbon polypeptide chains are identical, while the human and rhesus monkey sequences differ by 1 amino acid. This suggests that gibbons are more closely related to humans than rhesus monkeys. Practical Applications of Genomic Analysis 🎯 Detecting Consumer Fraud Genomic analysis can be used to detect consumer fraud, such as mislabeling of food products. For example, a piece of salmon labeled as coho salmon (Oncorhynchus kisutch) can be compared to known sequences from the same gene for three salmon species to determine its true identity. Species DNA Sequence Sample labeled as O. kisutch 5' C G G C A C C G C C C T A A G T C T C T 3' O. kisutch (coho salmon) 5' A G G C A C C G C C C T A A G T C T A C 3' O. keta (chum salmon) 5' A G G C A C C G C C C T G A G C C T A C 3' Salmo salar (Atlantic salmon) 5' C G G C A C C G C C C T A A G T C T C T 3' Interpreting the Data Page 17  Created by Turbolearn AI The DNA sequence of the sample labeled as O. kisutch is identical to that of Salmo salar (Atlantic salmon), suggesting that the sample is actually Atlantic salmon. This highlights the importance of genomic analysis in detecting consumer fraud. Concept Check 🤔 How would sequencing the entire genome of an organism help scientists understand how that organism functions? "Sequencing the entire genome of an organism would provide a complete picture of its genetic makeup, allowing scientists to understand how the organism functions and how it responds to its environment." Given the function of DNA, why would you expect two species with very similar traits to also have very similar genomes? "Two species with very similar traits are likely to have similar DNA sequences because DNA determines the traits of an organism. Therefore, similar traits suggest similar DNA sequences." Page 18