CH5 Biological Molecules
____________ proteins Function: Protection against disease Example: ____________ inactivate and help destroy viruses and bacteria.
Defensive proteins Function: Protection against disease Example: Antibodies inactivate and help destroy viruses and bacteria.
-Lipids are hydrophobic because they consist mostly of _____________ , which form ___________ ________ bonds -The most biologically important lipids are fats, phospholipids, and steroids
-Lipids are hydrophobic because they consist mostly of hydrocarbons, which form nonpolar covalent bonds -The most biologically important lipids are fats, phospholipids, and steroids
-Monomers are connected by covalent bonds that form through the loss of a water molecule. This reaction is called a ___________ __________ -When a bond forms between two monomers, each monomer contributes part of the ___________ molecule that is lost. One monomer provides a __________ group (—OH), while the other provides a ____________ atom (—H). -Cells invest energy to carry out dehydration reactions.
-Monomers are connected by covalent bonds that form through the loss of a water molecule. This reaction is called a dehydration reaction. -When a bond forms between two monomers, each monomer contributes part of the water molecule that is lost. One monomer provides a hydroxyl group (—OH), while the other provides a hydrogen atom (—H). -Cells invest energy to carry out dehydration reactions.
-Starch (____ configuration) is largely ______________ -Cellulose (____ configuration) are ______________ and ______________
-Starch (α configuration) is largely helical -Cellulose (β configuration) are straight and unbranched
-ketone (>C=O) is when the C=O is ..... -aldehyde is when the C=O is ....
-ketone (>C=O) is when the C=O is in the middle -aldehyde is when the C=O is on the end
A _________________ is formed when a dehydration reaction joins two monosaccharides --the covalent bond is called a ...
A disaccharide is formed when a dehydration reaction joins two monosaccharides -glycosidic linkage
___________________ proteins Function: Movement Examples: Motor proteins are responsible for the undulations of _______ and ________ . _________ and ________ proteins are responsible for the contraction of muscles.
Contractile and motor proteins Function: Movement Examples: Motor proteins are responsible for the undulations of cilia and flagella. Actin and myosin proteins are responsible for the contraction of muscles.
____________ proteins Function: -Selective acceleration of chemical reactions Example: __________ enzymes catalyze the hydrolysis of bonds in food molecules.
Enzymatic proteins Function: -Selective acceleration of chemical reactions Example: Digestive enzymes catalyze the hydrolysis of bonds in food molecules.
_____________ is an approach of addressing problems by analyzing large sets of genes or comparing whole genomes of different species. Similar to genomics, proteomic is the approach that analyzes large sets of __________ sequences.
Genomics is an approach of addressing problems by analyzing large sets of genes or comparing whole genomes of different species. Similar to genomics, proteomic is the approach that analyzes large sets of protein sequences.
____________ proteins - Function: Coordination of an organism's ____________ Example: Insulin, a hormone secreted by the pancreas, causes other tissues to take up ___________ , thus regulating blood sugar concentration.
Hormonal proteins - Function: Coordination of an organism's activities Example: Insulin, a hormone secreted by the pancreas, causes other tissues to take up glucose, thus regulating blood sugar concentration.
Pleated sheets are found in many globular proteins, such as transthyretin, and they dominate some fibrous proteins, including the silk protein of a spider's web. The presence of so many hydrogen bonds makes each silk fiber stronger than a steel strand of the same weight.
Pleated sheets are found in many globular proteins, such as transthyretin, and they dominate some fibrous proteins, including the silk protein of a spider's web. The presence of so many hydrogen bonds makes each silk fiber stronger than a steel strand of the same weight.
____________ proteins Function: Response of cell to chemical ___________ Example: Receptors built into the membrane of a nerve cell detect signaling __________ released by other nerve cells.
Receptor proteins Function: Response of cell to chemical stimuli Example: Receptors built into the membrane of a nerve cell detect signaling molecules released by other nerve cells.
______________ proteins Function: Storage of amino acids Examples: Casein, the protein of milk, is the major source of ________ _______ for baby mammals. Plants have storage proteins in their seeds. Ovalbumin is the protein of egg white, used as an _________ _______ source for the developing embryo.
Storage proteins Function: Storage of amino acids Examples: Casein, the protein of milk, is the major source of amino acids for baby mammals. Plants have storage proteins in their seeds. Ovalbumin is the protein of egg white, used as an amino acid source for the developing embryo.
__________ proteins Function: Support Examples: __________ is the protein of hair, horns, feathers, and other skin appendages. Insects and spiders use silk fibers to make their cocoons and webs, respectively. _____________ and elastin proteins provide a fibrous framework in animal connective tissues.
Structural proteins Function: Support Examples: Keratin is the protein of hair, horns, feathers, and other skin appendages. Insects and spiders use silk fibers to make their cocoons and webs, respectively. Collagen and elastin proteins provide a fibrous framework in animal connective tissues.
Tertiary structure, the overall shape of a polypeptide, results from interactions between _____ _______, rather than interactions between _____________ constituents -determined by interactions among various R groups.
Tertiary structure, the overall shape of a polypeptide, results from interactions between R groups, rather than interactions between backbone constituents -determined by interactions among various R groups.
The Roles of Nucleic Acids ▪There are two types of nucleic acids -- ? -- ? ▪DNA provides ___________for its own replication ▪DNA directs synthesis of ___________ _________ (mRNA) and, through mRNA, controls __________ synthesis ▪This process is called gene expression
The Roles of Nucleic Acids ▪There are two types of nucleic acids ▪Deoxyribonucleic acid (DNA) ▪Ribonucleic acid (RNA) ▪DNA provides directions for its own replication ▪DNA directs synthesis of messenger RNA (mRNA) and, through mRNA, controls protein synthesis ▪This process is called gene expression
The Structures of DNA and RNA Molecules ▪DNA molecules have two polynucleotides spiraling around an imaginary axis, forming a __________ _________ ▪The backbones run in opposite 5′ → 3′ directions from each other, an arrangement referred to as _____________ ▪One DNA molecule includes many genes
The Structures of DNA and RNA Molecules ▪DNA molecules have two polynucleotides spiraling around an imaginary axis, forming a double helix ▪The backbones run in opposite 5′ → 3′ directions from each other, an arrangement referred to as antiparallel ▪One DNA molecule includes many genes
___________ proteins Function: Transport of substances Examples: Hemoglobin, the iron-containing protein of ____________ blood, transports oxygen from the lungs to other parts of the body. Other proteins transport molecules across membranes, as shown here.
Transport proteins Function: Transport of substances Examples: Hemoglobin, the iron-containing protein of vertebrate blood, transports oxygen from the lungs to other parts of the body. Other proteins transport molecules across membranes, as shown here.
macromolecules
polymers built from monomers
§The folding of many proteins is assisted by ___________, or chaperone proteins. §Chaperonins do not specify the final structure of a polypeptide but rather work to ____________ and protect the polypeptide while it folds spontaneously. §Molecular systems in the cell interact with chaperonins, marking incorrectly folded proteins for __________ or for ___________ . §Accumulation of incorrectly folded polypeptides is associated with many diseases, including Alzeimer's, Parkinson's, and mad cow disease.
§The folding of many proteins is assisted by chaperonins, or chaperone proteins. §Chaperonins do not specify the final structure of a polypeptide but rather work to segregate and protect the polypeptide while it folds spontaneously. §Molecular systems in the cell interact with chaperonins, marking incorrectly folded proteins for refolding or for destruction. §Accumulation of incorrectly folded polypeptides is associated with many diseases, including Alzeimer's, Parkinson's, and mad cow disease.
§Two species that appear to be closely related based on fossil and molecular evidence should also be more similar in DNA and protein sequences than are more distantly related species. §Scientists can compare the sequence of 146 amino acids in the polypeptide chain of human _______________ to the sequences in five other vertebrates. §Humans and gorillas differ in just 1 amino acid, while humans and frogs differ in 67 amino acids. §Despite these differences, all the species have functional hemoglobin.
§Two species that appear to be closely related based on fossil and molecular evidence should also be more similar in DNA and protein sequences than are more distantly related species. §Scientists can compare the sequence of 146 amino acids in the polypeptide chain of human hemoglobin to the sequences in five other vertebrates. §Humans and gorillas differ in just 1 amino acid, while humans and frogs differ in 67 amino acids. §Despite these differences, all the species have functional hemoglobin.
·A functional protein consists of one or more polypeptides precisely twisted, folded, and coiled into a unique shape. ·It is the ___________ of amino acids that determines the three-dimensional structure of the protein under normal cellular conditions. ·A protein's specific structure determines its function. ·When a cell synthesizes a polypeptide, the chain generally folds ___________________ to assume the functional structure for that protein. ·The folding is reinforced by a variety of bonds between parts of the chain, which in turn depend on the sequence of amino acids. ·Many proteins are ________ , while others are ___________ in shape.
·A functional protein consists of one or more polypeptides precisely twisted, folded, and coiled into a unique shape. ·It is the order of amino acids that determines the three-dimensional structure of the protein under normal cellular conditions. ·A protein's specific structure determines its function. ·When a cell synthesizes a polypeptide, the chain generally folds spontaneously to assume the functional structure for that protein. ·The folding is reinforced by a variety of bonds between parts of the chain, which in turn depend on the sequence of amino acids. ·Many proteins are globular, while others are fibrous in shape.
•A gram of fat stores more than __________ as much energy as a gram of a polysaccharide such as starch. •Because plants are immobile, they can function with bulky energy storage in the form of ______________. Plants use _______ when dispersal and compact storage are important, as in seeds. •Animals must carry their energy stores with them, so they benefit from having a more ___________ fuel reservoir of fat.
•A gram of fat stores more than twice as much energy as a gram of a polysaccharide such as starch. •Because plants are immobile, they can function with bulky energy storage in the form of starch. Plants use oils when dispersal and compact storage are important, as in seeds. •Animals must carry their energy stores with them, so they benefit from having a more compact fuel reservoir of fat.
What Determines Protein Structure? •A polypeptide chain with a given amino acid sequence can spontaneously arrange itself into a _______-dimensional shape determined and maintained by the interactions responsible for secondary and tertiary structure. •The folding occurs as the protein is __________ within the cell. •Protein structure also depends on the _________ and __________ conditions of the protein's environment.
•A polypeptide chain with a given amino acid sequence can spontaneously arrange itself into a three-dimensional shape determined and maintained by the interactions responsible for secondary and tertiary structure. •The folding occurs as the protein is synthesized within the cell. •Protein structure also depends on the physical and chemical conditions of the protein's environment.
•Each ________ along a DNA molecule directs the synthesis of messenger RNA (mRNA). •The mRNA molecule interacts with the cell's protein-synthesizing machinery to direct the ordering of ___________ ________ in a polypeptide. •The flow of genetic information is DNA --> RNA --> protein. •Protein synthesis occurs on cellular structures called __________.
•Each gene along a DNA molecule directs the synthesis of a specific type of RNA called messenger RNA (mRNA). •The mRNA molecule interacts with the cell's protein-synthesizing machinery to direct the ordering of amino acids in a polypeptide. •The flow of genetic information is DNA --> RNA --> protein. •Protein synthesis occurs on cellular structures called ribosomes.
•Alterations in pH, salt concentration, temperature, or other factors can unravel or ____________ a protein. •These forces disrupt the weak chemical bonds and interactions within a protein that maintain its shape. •Because it is misshapen, a denatured protein is biologically _________. •Most proteins become denatured if they are transferred from an ___________ environment to a _____________ solvent. •The polypeptide chain refolds so that its hydrophobic regions face outward, toward the _______________.
•Alterations in pH, salt concentration, temperature, or other factors can unravel or denature a protein. •These forces disrupt the weak chemical bonds and interactions within a protein that maintain its shape. •Because it is misshapen, a denatured protein is biologically inactive. •Most proteins become denatured if they are transferred from an aqueous environment to a nonpolar solvent. •The polypeptide chain refolds so that its hydrophobic regions face outward, toward the solvent.
•Although fats are not strictly polymers, they are large molecules assembled from smaller molecules via ________________ reactions. •A fat is constructed from two kinds of smaller molecules: _____________ and ________ ________ •Glycerol is a three-___________ alcohol with a ___________ __________ attached to each carbon. •A fatty acid consists of a _______________ group attached to a long carbon skeleton, often 16 to 18 carbons long. •The many nonpolar C—H bonds in the long hydrocarbon skeleton make fats ______________.
•Although fats are not strictly polymers, they are large molecules assembled from smaller molecules via dehydration reactions. •A fat is constructed from two kinds of smaller molecules: glycerol and fatty acids. •Glycerol is a three-carbon alcohol with a hydroxyl group attached to each carbon. •A fatty acid consists of a carboxyl group attached to a long carbon skeleton, often 16 to 18 carbons long. •The many nonpolar C—H bonds in the long hydrocarbon skeleton make fats hydrophobic.
•Although glucose is often drawn with a linear carbon skeleton, most sugars (including glucose) form _________ in *aqueous* solution. •Monosaccharides, particularly glucose, are major _______________ for cellular work. •Cells extract ____________ from glucose molecules in the process of _______________ _____________
•Although glucose is often drawn with a linear carbon skeleton, most sugars (including glucose) form rings in aqueous solution. •Monosaccharides, particularly glucose, are major nutrients for cellular work. •Cells extract energy from glucose molecules in the process of cellular respiration.
•Amino acids are joined together when a dehydration reaction removes a ___________ group from the carboxyl end of one amino acid and a __________ atom from the amino group of another. •The resulting covalent bond is called a peptide bond. •Repeating the process over and over creates a polypeptide chain. •At one end is an amino acid with a free amino group (the ____-terminus), and at the other end is an amino acid with a free carboxyl group (the ___-terminus). •Polypeptides range in size from a few monomers to thousands. •Each polypeptide has a unique linear sequence of amino acids.
•Amino acids are joined together when a dehydration reaction removes a hydroxyl group from the carboxyl end of one amino acid and a hydrogen atom from the amino group of another. •The resulting covalent bond is called a peptide bond. •Repeating the process over and over creates a polypeptide chain. •At one end is an amino acid with a free amino group (the N-terminus), and at the other end is an amino acid with a free carboxyl group (the C-terminus). •Polypeptides range in size from a few monomers to thousands. •Each polypeptide has a unique linear sequence of amino acids.
•Animals that feed on plants, especially parts rich in starch, have digestive enzymes that can ______________ starch to glucose, making the glucose available as a nutrient for cells. •________ and ____________ tubers are the main sources of starch in the human diet. •Most of the glucose monomers in starch are joined by _____ linkages (number 1 carbon to number 4 carbon).
•Animals that feed on plants, especially parts rich in starch, have digestive enzymes that can hydrolyze starch to glucose, making the glucose available as a nutrient for cells. •Grains and potato tubers are the main sources of starch in the human diet. •Most of the glucose monomers in starch are joined by 1-4 linkages (number 1 carbon to number 4 carbon).
•Another important structural polysaccharide is chitin, found in the ___________ of arthropods (including insects, spiders, and crustaceans). •Chitin is similar to cellulose, except that it has a _____________-containing appendage on each glucose monomer. •Pure chitin is leathery but can be _______________ by the addition of calcium carbonate. •Chitin also provides structural support for the _____ __________ of many fungi.
•Another important structural polysaccharide is chitin, found in the exoskeletons of arthropods (including insects, spiders, and crustaceans). •Chitin is similar to cellulose, except that it has a nitrogen-containing appendage on each glucose monomer. •Pure chitin is leathery but can be hardened by the addition of calcium carbonate. •Chitin also provides structural support for the cell walls of many fungi.
•At the center of an amino acid is an asymmetric carbon atom called the _____________ _____________ •Four components are attached to the α carbon: -a __________ _________ -a _________ group -an ___________ group -a variable ____ ________ (or side chain). •An R group may be as simple as a hydrogen atom (as in the amino acid glycine), or it may be a carbon skeleton with various functional groups attached (as in glutamine). •The physical and chemical properties of the R group determine the unique characteristics of a particular amino acid.
•At the center of an amino acid is an asymmetric carbon atom called the alpha (a) carbon. •Four components are attached to the α carbon: -a hydrogen atom -a carboxyl group -an amino group -a variable R group (or side chain). •An R group may be as simple as a hydrogen atom (as in the amino acid glycine), or it may be a carbon skeleton with various functional groups attached (as in glutamine). •The physical and chemical properties of the R group determine the unique characteristics of a particular amino acid.
Protein Folding in the Cell: •Biochemists now know the amino acid sequences of about 24 million proteins and the three-dimensional shapes of about 25,000. •Nevertheless, it is still difficult to predict the three-dimensional shape of a protein from its __________ structure alone. •Most proteins appear to undergo several intermediate stages before reaching their "mature" structure.
•Biochemists now know the amino acid sequences of about 24 million proteins and the three-dimensional shapes of about 25,000. •Nevertheless, it is still difficult to predict the three-dimensional shape of a protein from its primary structure alone. •Most proteins appear to undergo several intermediate stages before reaching their "mature" structure.
•Enzymes that digest starch by hydrolyzing its a linkages in starch and glycogen cannot hydrolyze the b linkages in ___________. •Cellulose in human food passes through the digestive tract and is eliminated in feces as "insoluble __________." •As it travels through the digestive tract, cellulose abrades the ______________ walls and stimulates the secretion of _________, which aids in the passage of food.
•Enzymes that digest starch by hydrolyzing its a linkages in starch and glycogen cannot hydrolyze the b linkages in cellulose. •Cellulose in human food passes through the digestive tract and is eliminated in feces as "insoluble fiber." •As it travels through the digestive tract, cellulose abrades the intestinal walls and stimulates the secretion of mucus, which aids in the passage of food.
•Even a slight change in the primary structure can affect a protein's conformation and ability to function. •The substitution of one amino acid (valine) for the normal one (glutamic acid) at a particular position in the primary structure of hemoglobin, the protein that carries ___________ in ______ blood cells, can cause sickle-cell disease, an inherited blood disorder. •The abnormal hemoglobin molecules crystallize, deforming some of the red blood cells into a sickle shape and clogging capillaries.
•Even a slight change in the primary structure can affect a protein's conformation and ability to function. •The substitution of one amino acid (valine) for the normal one (glutamic acid) at a particular position in the primary structure of hemoglobin, the protein that carries oxygen in red blood cells, can cause sickle-cell disease, an inherited blood disorder. •The abnormal hemoglobin molecules crystallize, deforming some of the red blood cells into a sickle shape and clogging capillaries.
▪Quaternary structure results when two or more polypeptide chains form one macromolecule •For example, globular transthyretin protein is made up of ______ polypeptides. •______________ is a fibrous protein made up of three polypeptides that are supercoiled into a larger triple helix. •The helix provides structural strength for collagen's role in ______________ tissue. •Hemoglobin is a __________ protein with quaternary structure. •Hemoglobin consists of four polypeptide subunits: two ____ and two ____ chains. •Both types of subunits consist of primarily a-__________ secondary structure. •Each subunit has a nonpeptide heme component with an iron atom that binds oxygen.
•For example, globular transthyretin protein is made up of four polypeptides. •Collagen is a fibrous protein made up of three polypeptides that are supercoiled into a larger triple helix. •The helix provides structural strength for collagen's role in connective tissue. •Hemoglobin is a globular protein with quaternary structure. •Hemoglobin consists of four polypeptide subunits: two a and two b chains. •Both types of subunits consist of primarily a-helical secondary structure. •Each subunit has a nonpeptide heme component with an iron atom that binds oxygen.
•Frederick Sanger and his colleagues at Cambridge University determined the amino acid sequence of __________ in the early 1950s. •Sanger used various protein-digesting enzymes and other catalysts to hydrolyze the insulin at specific places, yielding groups of small fragments. •Sanger used chemical methods to determine the sequences of amino acids in the small fragments. •After years of effort, Sanger was able to reconstruct the complete primary structure of insulin. •Most of the steps in sequencing a polypeptide have since been automated.
•Frederick Sanger and his colleagues at Cambridge University determined the amino acid sequence of insulin in the early 1950s. •Sanger used various protein-digesting enzymes and other catalysts to hydrolyze the insulin at specific places, yielding groups of small fragments. •Sanger used chemical methods to determine the sequences of amino acids in the small fragments. •After years of effort, Sanger was able to reconstruct the complete primary structure of insulin. •Most of the steps in sequencing a polypeptide have since been automated.
•Glycogen is similar to amylopectin , but more highly ________________ . •Humans and other vertebrates store a day's supply of glycogen in the liver and muscles, hydrolyzing it to release glucose to meet the body's demand for sugar.
•Glycogen is similar to amylopectin , but more highly branched. •Humans and other vertebrates store a day's supply of glycogen in the liver and muscles, hydrolyzing it to release glucose to meet the body's demand for sugar.
•Humans and other mammals store fats as long-term energy reserves in ___________ cells that swell and shrink as fat is deposited and withdrawn from storage. •Adipose tissue also functions to cushion vital organs, such as the kidneys. •A layer of fat can function as insulation. •This subcutaneous layer is especially thick in whales, seals, and most other marine mammals.
•Humans and other mammals store fats as long-term energy reserves in adipose cells that swell and shrink as fat is deposited and withdrawn from storage. •Adipose tissue also functions to cushion vital organs, such as the kidneys. •A layer of fat can function as insulation. •This subcutaneous layer is especially thick in whales, seals, and most other marine mammals.
•If the fatty acid has no carbon-carbon double bonds, then the molecule is a _______________ fatty acid, saturated with _____________ at every possible position. •If the fatty acid has one or more carbon-carbon double bonds formed by the _______________ of hydrogen atoms from the carbon skeleton, then the molecule is an _________________ fatty acid. •A saturated fatty acid is a straight chain, but an unsaturated fatty acid has a kink wherever there is a _____ double bond.
•If the fatty acid has no carbon-carbon double bonds, then the molecule is a saturated fatty acid, saturated with hydrogens at every possible position. •If the fatty acid has one or more carbon-carbon double bonds formed by the removal of hydrogen atoms from the carbon skeleton, then the molecule is an unsaturated fatty acid. •A saturated fatty acid is a straight chain, but an unsaturated fatty acid has a kink wherever there is a cis double bond.
•In a fat, three fatty acids are joined to glycerol by an _________ ____________ , creating a triacylglycerol, or triglyceride. •The three fatty acids in a fat can be the _________ or different.
•In a fat, three fatty acids are joined to glycerol by an ester linkage, creating a triacylglycerol, or triglyceride. •The three fatty acids in a fat can be the same or different.
•The simplest form of starch, amylose, is __________________. •Branched forms such as _____________ are more complex. •polymers built with α glucose form ____________ structures
•The simplest form of starch, amylose, is unbranched. •Branched forms such as amylopectin are more complex. •polymers built with α glucose form helical structures
•In almost every case, the function of a protein depends on its ability to recognize and ________ to some other molecule. •For example, an ___________ binds to a particular foreign substance. •Natural signal molecules called ____________ bind to specific receptor proteins on the surface of brain cells in humans, producing euphoria and relieving pain. •Morphine, heroin, and other opiate drugs mimic endorphins because they are similar in shape and can bind to the brain's endorphin receptors. •The function of a protein is an emergent property resulting from its specific molecular ________.
•In almost every case, the function of a protein depends on its ability to recognize and bind to some other molecule. •For example, an antibody binds to a particular foreign substance. •Natural signal molecules called endorphins bind to specific receptor proteins on the surface of brain cells in humans, producing euphoria and relieving pain. •Morphine, heroin, and other opiate drugs mimic endorphins because they are similar in shape and can bind to the brain's endorphin receptors. •The function of a protein is an emergent property resulting from its specific molecular order.
•In cellulose the number 1 carbon is fixed above (b glucose) the plane of the ring. •The straight structures built with β glucose allow H atoms on one strand to form ____________ bonds with OH groups on other strands. •In plant cell walls, parallel cellulose molecules held together in this way are grouped into units called ___________ , which form strong building materials for plants. •Cellulose microfibrils are important constituents of wood, paper, and cotton. •
•In cellulose the number 1 carbon is fixed above (b glucose) the plane of the ring. •The straight structures built with β glucose allow H atoms on one strand to form hydrogen bonds with OH groups on other strands. •In plant cell walls, parallel cellulose molecules held together in this way are grouped into units called microfibrils, which form strong building materials for plants. •Cellulose microfibrils are important constituents of wood, paper, and cotton. •
•In eukaryotes, DNA is located in the nucleus, but most ribosomes are in the ___________. •________functions as an intermediary, moving genetic instructions for building proteins from the nucleus to the cytoplasm. •________________ lack nuclei but still use mRNA as an intermediary to carry a message from DNA to the ribosomes.
•In eukaryotes, DNA is located in the nucleus, but most ribosomes are in the cytoplasm. •mRNA functions as an intermediary, moving genetic instructions for building proteins from the nucleus to the cytoplasm. •Prokaryotes lack nuclei but still use mRNA as an intermediary to carry a message from DNA to the ribosomes.
•Monosaccharides are also classified by the size of the ___________ _____________ •The carbon skeleton of a sugar ranges from __________ to _____________ carbons long. •Glucose and other six-carbon sugars are _______________ . •Five-carbon sugars are ___________ ; three-carbon sugars are __________ . •Another source of diversity for simple sugars is the ___________ arrangement of their parts around asymmetric carbon atoms. •For example, glucose and galactose, both six-carbon aldoses, differ only in the spatial arrangement of their parts around asymmetric carbons.
•Monosaccharides are also classified by the size of the carbon skeleton. •The carbon skeleton of a sugar ranges from three to seven carbons long. •Glucose and other six-carbon sugars are hexoses. •Five-carbon sugars are pentoses; three-carbon sugars are trioses. •Another source of diversity for simple sugars is the spatial arrangement of their parts around asymmetric carbon atoms. •For example, glucose and galactose, both six-carbon aldoses, differ only in the spatial arrangement of their parts around asymmetric carbons.
•Monosaccharides are classified by: -- the location of the _______________ group (as _________ or ______________ ) -- the number of carbons in the _____________ ________________ •Monosaccharides have a carbonyl group (________) and multiple hydroxyl groups (_________). •Depending on the location of the carbonyl group, the sugar is an ___________ (aldehyde sugar) or a _______________ (ketone sugar). •Most names for sugars end in -ose.
•Monosaccharides are classified by --the location of the carbonyl group (as aldose or ketose) --the number of carbons in the carbon skeleton •Monosaccharides have a carbonyl group (>C=O) and multiple hydroxyl groups (—OH). •Depending on the location of the carbonyl group, the sugar is an aldose (aldehyde sugar) or a ketose (ketone sugar). •Most names for sugars end in -ose.
•Most important, protein enzymes function as catalysts in cells, regulating _____________ by selectively accelerating certain chemical reactions without being consumed. •Humans have tens of thousands of different proteins, each with a specific structure and function. •Proteins are the most structurally complex molecules known. •Each type of protein has a complex _________ -dimensional shape.
•Most important, protein enzymes function as catalysts in cells, regulating metabolism by selectively accelerating certain chemical reactions without being consumed. •Humans have tens of thousands of different proteins, each with a specific structure and function. •Proteins are the most structurally complex molecules known. •Each type of protein has a complex three-dimensional shape.
•Most proteins have segments of their polypeptide chains repeatedly coiled or folded. •These coils and folds are referred to as secondary structure and result from ___________ ____________________ between the repeating constituents of the polypeptide backbone. •The weakly _____________ hydrogen atom attached to the nitrogen atom has an affinity for the oxygen atom of a nearby peptide bond. •Each hydrogen bond is ________ , but the sum of many hydrogen bonds stabilizes the structure of part of the protein.
•Most proteins have segments of their polypeptide chains repeatedly coiled or folded. •These coils and folds are referred to as secondary structure and result from hydrogen bonds between the repeating constituents of the polypeptide backbone. •The weakly positive hydrogen atom attached to the nitrogen atom has an affinity for the oxygen atom of a nearby peptide bond. •Each hydrogen bond is weak, but the sum of many hydrogen bonds stabilizes the structure of part of the protein.
The Components of Nucleic Acids ▪Nucleic acids are polymers called ________________ ▪Each polynucleotide is made of monomers called _______________ ▪Each nucleotide consists of a __________________ , a _______________, and one or more ___________________ ▪The portion of a nucleotide without the phosphate group is called a _________________
▪Nucleic acids are polymers called polynucleotides ▪Each polynucleotide is made of monomers called nucleotides ▪Each nucleotide consists of a nitrogenous base, a pentose sugar, and one or more phosphate groups ▪The portion of a nucleotide without the phosphate group is called a nucleoside
•One group of amino acids has nonpolar R groups, which are ______________ . •Another group of amino acids has polar R groups, which are ______________. •A third group of amino acids has functional groups that are _______________ (ionized) at cellular pH. •Some acidic R groups have negative charge due to the presence of a __________ group. •Basic R groups have amino groups with _____________ charge. •All amino acids have carboxyl and amino groups. The terms acidic and basic in this context refer only to these groups in the R groups.
•One group of amino acids has nonpolar R groups, which are hydrophobic. •Another group of amino acids has polar R groups, which are hydrophilic. •A third group of amino acids has functional groups that are charged (ionized) at cellular pH. •Some acidic R groups have negative charge due to the presence of a carboxyl group. •Basic R groups have amino groups with positive charge. •All amino acids have carboxyl and amino groups. The terms acidic and basic in this context refer only to these groups in the R groups.
•One secondary structure is the a helix, a delicate _______ held together by hydrogen bonding between every __________ amino acid, as found in transthyretin. •Some fibrous proteins, such as a-___________ , the structural protein of hair, have the a helix formation over most of their length. •The other main type of secondary structure is the b pleated sheet. •In this structure, two or more regions of the polypeptide chain lying side by side are connected by hydrogen bonds between parts of the two ___________ polypeptide backbones.
•One secondary structure is the a helix, a delicate coil held together by hydrogen bonding between every fourth amino acid, as found in transthyretin. •Some fibrous proteins, such as a-keratin, the structural protein of hair, have the a helix formation over most of their length. •The other main type of secondary structure is the b pleated sheet. •In this structure, two or more regions of the polypeptide chain lying side by side are connected by hydrogen bonds between parts of the two parallel polypeptide backbones.
•Organisms inherit DNA from their parents. •Each DNA molecule is very long, carrying several hundred or more __________. •Before a cell reproduces itself by dividing, its DNA is copied. The copies are then passed to the next generation of cells. •Although DNA encodes the information that programs all the cell's activities, it is not directly involved in the ____________ operations of the cell.
•Organisms inherit DNA from their parents. •Each DNA molecule is very long, carrying several hundred or more genes. •Before a cell reproduces itself by dividing, its DNA is copied. The copies are then passed to the next generation of cells. •Although DNA encodes the information that programs all the cell's activities, it is not directly involved in the day-to-day operations of the cell.
Phospholipids-Cell Membrane Structure •Phospholipids have ________ fatty acids attached to ___________ and a ________ ___________ at the third position. •The phosphate group carries a ____________ charge. •Additional smaller groups (usually charged or polar) may be attached to the phosphate group to form a variety of phospholipids.
•Phospholipids have two fatty acids attached to glycerol and a phosphate group at the third position. •The phosphate group carries a negative charge. •Additional smaller groups (usually charged or polar) may be attached to the phosphate group to form a variety of phospholipids.
•Prior to cell division, each of the strands serves as a _____________to order nucleotides in a new complementary strand. •This results in two identical copies of the original double-stranded DNA molecule, which are then distributed to the ________________ cells. •This mechanism ensures that a full set of genetic information is transmitted whenever a cell reproduces.
•Prior to cell division, each of the strands serves as a template to order nucleotides in a new complementary strand. •This results in two identical copies of the original double-stranded DNA molecule, which are then distributed to the daughter cells. •This mechanism ensures that a full set of genetic information is transmitted whenever a cell reproduces.
•Some microbes can digest cellulose to its glucose monomers through the use of ____________ enzymes. •Many eukaryotic herbivores, from cows to termites, have symbiotic relationships with cellulose-digesting _____________ and ___________, providing the microbes and the host animal access to a rich source of energy. •Some fungi can also digest cellulose.
•Some microbes can digest cellulose to its glucose monomers through the use of cellulase enzymes. •Many eukaryotic herbivores, from cows to termites, have symbiotic relationships with cellulose-digesting prokaryotes and protists, providing the microbes and the host animal access to a rich source of energy. •Some fungi can also digest cellulose.
•__________ is a polysaccharide of alpha (a) glucose monomers. •Cellulose is a polysaccharide of beta (b) glucose monomers, making every other glucose monomer upside down with respect to its neighbors. •The differing glycosidic linkages in starch and cellulose are what give the two molecules distinct three-dimensional shapes.
•Starch is a polysaccharide of alpha (a) glucose monomers. •Cellulose is a polysaccharide of beta (b) glucose monomers, making every other glucose monomer upside down with respect to its neighbors. •The differing glycosidic linkages in starch and cellulose are what give the two molecules distinct three-dimensional shapes.
•The covalent bonds that connect monomers in a polymer are disassembled by _____________ , a reaction that is effectively the reverse of dehydration. •In hydrolysis, bonds are broken by the ___________ of water molecules. A hydrogen atom attaches to one monomer, and a hydroxyl group attaches to the adjacent monomer.
•The covalent bonds that connect monomers in a polymer are disassembled by hydrolysis, a reaction that is effectively the reverse of dehydration. •In hydrolysis, bonds are broken by the addition of water molecules. A hydrogen atom attaches to one monomer, and a hydroxyl group attaches to the adjacent monomer.
Nucleotide Polymers ▪Nucleotides are linked together to build a polynucleotide ▪The sequence of bases along a DNA or mRNA polymer is unique for each __________
▪Nucleotides are linked together to build a polynucleotide ▪The sequence of bases along a DNA or mRNA polymer is unique for each gene
Polysaccharides ▪_______________ , the polymers of sugars, have storage and structural roles ▪The architecture and function of a polysaccharide are determined by its sugar ________ and the positions of its _________________ linkages
▪Polysaccharides, the polymers of sugars, have storage and structural roles ▪The architecture and function of a polysaccharide are determined by its sugar monomers and the positions of its glycosidic linkages
•The interaction of phospholipids with water is complex. •The fatty acid tails are ________________ , but the __________ ____________ and its attachments form a hydrophilic head. •When phospholipids are added to water, they form assemblages with the hydrophobic tails pointing toward the ___________ . •Phospholipids are arranged as a bilayer at the surface of a cell. •The _______________ heads are on the outside of the bilayer, in contact with the aqueous solution, and the hydrophobic tails point toward the interior of the bilayer. •The phospholipid bilayer forms a barrier between the cell and the external environment. •Phospholipids are the major component of all cell membranes.
•The interaction of phospholipids with water is complex. •The fatty acid tails are hydrophobic, but the phosphate group and its attachments form a hydrophilic head. •When phospholipids are added to water, they form assemblages with the hydrophobic tails pointing toward the interior. •Phospholipids are arranged as a bilayer at the surface of a cell. •The hydrophilic heads are on the outside of the bilayer, in contact with the aqueous solution, and the hydrophobic tails point toward the interior of the bilayer. •The phospholipid bilayer forms a barrier between the cell and the external environment. •Phospholipids are the major component of all cell membranes.
•The kinks caused by the cis double bonds prevent the molecules from packing tightly enough to ____________ at room temperature. •Fats made from saturated fatty acids are saturated fats. Fats made from unsaturated fatty acids are unsaturated fats. •Most _____________ fats are saturated and are solid at room temperature. •Plant and fish fats are liquid at room temperature and are known as ______.
•The kinks caused by the cis double bonds prevent the molecules from packing tightly enough to solidify at room temperature. •Fats made from saturated fatty acids are saturated fats. Fats made from unsaturated fatty acids are unsaturated fats. •Most animal fats are saturated and are solid at room temperature. •Plant and fish fats are liquid at room temperature and are known as oils.
•The nitrogenous bases are rings of __________ and ___________ that come in two types: purines and pyrimidines. •Pyrimidines have a single ____-membered ring of carbon and nitrogen atoms. •There are three different pyrimidines: - - - •_______________ is found only in DNA and ______________ is found only in RNA. •Purines have a _______ -membered ring joined to a _______-membered ring. •The two purines are - -
•The nitrogenous bases are rings of carbon and nitrogen that come in two types: purines and pyrimidines. •Pyrimidines have a single six-membered ring of carbon and nitrogen atoms. •There are three different pyrimidines: cytosine (C), thymine (T), and uracil (U). •Thymine is found only in DNA and uracil is found only in RNA. •Purines have a six-membered ring joined to a five-membered ring. •The two purines are adenine (A) and guanine (G).
•The only difference between the sugars in RNA and DNA is the lack of an ___________ atom on carbon ____ in deoxyribose. •Because the atoms in both the nitrogenous base and the sugar are numbered, the ________ _________ are distinguished by a prime (') after the number. •Thus, the second carbon in the sugar ring is the 2¢ (2 prime) carbon, and the carbon that sticks up from the ring is the 5¢ carbon.
•The only difference between the sugars in RNA and DNA is the lack of an oxygen atom on carbon 2 in deoxyribose. •Because the atoms in both the nitrogenous base and the sugar are numbered, the sugar atoms are distinguished by a prime (¢) after the number. •Thus, the second carbon in the sugar ring is the 2¢ (2 prime) carbon, and the carbon that sticks up from the ring is the 5¢ carbon.
•The phrase "hydrogenated vegetable oils" on food labels means that unsaturated fats have been synthetically converted to saturated fats by the addition of ____________ . •Peanut butter and margarine are _________________ to prevent lipids from separating out as oil. •A diet rich in saturated fats may contribute to cardiovascular disease (atherosclerosis) through plaque deposits. •The process of hydrogenating vegetable oils produces saturated fats and also unsaturated fats with _____________ ______________ bonds. These trans fat molecules contribute more than saturated fats to atherosclerosis.
•The phrase "hydrogenated vegetable oils" on food labels means that unsaturated fats have been synthetically converted to saturated fats by the addition of hydrogen. •Peanut butter and margarine are hydrogenated to prevent lipids from separating out as oil. •A diet rich in saturated fats may contribute to cardiovascular disease (atherosclerosis) through plaque deposits. •The process of hydrogenating vegetable oils produces saturated fats and also unsaturated fats with trans double bonds. These trans fat molecules contribute more than saturated fats to atherosclerosis.
•The primary structure of a protein is its unique sequence of amino acids. •Transthyretin is a globular protein found in the blood that transports vitamin _____ and a particular ____________ hormone throughout the body. --Each of the four identical polypeptide chains that, together, make up transthyretin is composed of 127 amino acids. •The precise primary structure of each of the polypeptide chains is determined by __________ _________ information, not by the random linking of amino acids.
•The primary structure of a protein is its unique sequence of amino acids. •Transthyretin is a globular protein found in the blood that transports vitamin A and a particular thyroid hormone throughout the body. •Each of the four identical polypeptide chains that, together, make up transthyretin is composed of 127 amino acids. •The precise primary structure of each of the polypeptide chains is determined by inherited genetic information, not by the random linking of amino acids.
•The process of digestion is an example of ___________ within the human body. •We take in food as organic polymers that are too large for our cells to _____________. In the digestive tract, ___________________ direct the hydrolysis of specific polymers. The resulting monomers are absorbed by the cells lining the gut and transported to the ________________ for distribution to body cells. •The cells of our body then use ___________________ reactions to assemble the monomers into new and different polymers that carry out functions specific to the particular cell type.
•The process of digestion is an example of hydrolysis within the human body. •We take in food as organic polymers that are too large for our cells to absorb. In the digestive tract, enzymes direct the hydrolysis of specific polymers. The resulting monomers are absorbed by the cells lining the gut and transported to the bloodstream for distribution to body cells. •The cells of our body then use dehydration reactions to assemble the monomers into new and different polymers that carry out functions specific to the particular cell type.
•The two polynucleotides or strands are held together by ___________ bonds between the paired bases. •Most DNA molecules have thousands to millions of base pairs, and may contain many genes •Because of their shapes, only some bases are compatible with each other. •___________ (A) always pairs with ______________ and guanine (G) with _______________ •With these base-pairing rules, if we know the sequence of bases on one strand, we know the sequence on the ________________ strand. •The two strands are complementary.
•The two polynucleotides or strands are held together by hydrogen bonds between the paired bases. •Most DNA molecules have thousands to millions of base pairs, and may contain many genes •Because of their shapes, only some bases are compatible with each other. •Adenine (A) always pairs with thymine (T) and guanine (G) with cytosine (C). •With these base-pairing rules, if we know the sequence of bases on one strand, we know the sequence on the opposite strand. •The two strands are complementary.
•These interactions include --hydrogen bonds between _________ and/or charged areas --_________ bonds between charged R groups --hydrophobic interactions and _______ ________ _________ interactions among hydrophobic R groups •Although these three interactions are relatively weak, their cumulative effect helps give the protein a unique shape. •Strong covalent bonds called ____________ _________ that form between the sulfhydryl groups (SH) of two ___________ monomers act to rivet parts of the protein together.
•These interactions include --hydrogen bonds between polar and/or charged areas --ionic bonds between charged R groups --hydrophobic interactions and van der Waals interactions among hydrophobic R groups •Although these three interactions are relatively weak, their cumulative effect helps give the protein a unique shape. •Strong covalent bonds called disulfide bridges that form between the sulfhydryl groups (SH) of two cysteine monomers act to rivet parts of the protein together.
Macromolecules are polymers, built from monomers ▪A ___________is a long molecule consisting of many similar building blocks ▪The repeating units that serve as building blocks are called _________ ▪Three of the four classes of life's organic molecules are polymers
▪A polymer is a long molecule consisting of many similar building blocks ▪The repeating units that serve as building blocks are called monomers ▪Three of the four classes of life's organic molecules are polymers
Amino Acids ▪Amino acids are ___________ molecules with amino and carboxyl groups ▪Amino acids differ in their properties due to differing side chains, called ____ groups
▪Amino acids are organic molecules with amino and carboxyl groups ▪Amino acids differ in their properties due to differing side chains, called R groups
▪Bioinformatics uses computer software and other computational tools to deal with the data resulting from ______________ many ______________________
▪Bioinformatics uses computer software and other computational tools to deal with the data resulting from sequencing many genomes
Carbohydrates serve as fuel and building material ▪Carbohydrates include ____________ and the __________ of sugars ▪The simplest carbohydrates are ____________ , or simple sugars ▪Carbohydrate macromolecules are ____________, polymers composed of many sugar building blocks
▪Carbohydrates include sugars and the polymers of sugars ▪The simplest carbohydrates are monosaccharides, or simple sugars ▪Carbohydrate macromolecules are polysaccharides, polymers composed of many sugar building blocks
▪Certain unsaturated fatty acids are not synthesized in the human body ▪These must be supplied in the _______________ ▪These essential fatty acids include the omega-3 and omega-6 fatty acids, which are required for normal growth
▪Certain unsaturated fatty acids are not synthesized in the human body ▪These must be supplied in the diet ▪These essential fatty acids include the omega-3 and omega-6 fatty acids, which are required for normal growth
The Diversity of Polymers ▪Each cell has thousands of different macromolecules ▪Macromolecules vary among cells of an organism, vary more within a ____________ , and vary even more between species ▪A huge variety of polymers can be built from a small set of monomers
▪Each cell has thousands of different macromolecules ▪Macromolecules vary among cells of an organism, vary more within a species, and vary even more between species ▪A huge variety of polymers can be built from a small set of monomers
The Synthesis and Breakdown of Polymers ▪Enzymes are specialized ______________ that speed up chemical reactions such as those that make or break down polymers
▪Enzymes are specialized macromolecules that speed up chemical reactions such as those that make or break down polymers
▪Enzymes that digest starch by hydrolyzing ____ linkages can't hydrolyze ____ linkages in cellulose
▪Enzymes that digest starch by hydrolyzing α linkages can't hydrolyze β linkages in cellulose
▪Fats separate from water because water molecules ____________ -bond to each other and exclude the fats
▪Fats separate from water because water molecules hydrogen-bond to each other and exclude the fats
Polysaccharide - Animals ▪_______________ is a storage polysaccharide in animals ▪Glycogen is stored mainly in _______ and ___________cells ▪___________ of glycogen in these cells releases glucose when the demand for sugar increases
▪Glycogen is a storage polysaccharide in animals ▪Glycogen is stored mainly in liver and muscle cells ▪Hydrolysis of glycogen in these cells releases glucose when the demand for sugar increases
Lipids are a diverse group of hydrophobic molecules ▪Lipids are the one class of large biological molecules that does not include true ____________ ▪The unifying feature of lipids is that they mix poorly, if at all, with water
▪Lipids are the one class of large biological molecules that does not include true polymers ▪The unifying feature of lipids is that they mix poorly, if at all, with water
Sugars ▪Monosaccharides have molecular formulas that are usually multiples of ___________ ▪_______________ (C6H12O6) is the most common monosaccharide
▪Monosaccharides have molecular formulas that are usually multiples of CH2O ▪Glucose (C6H12O6) is the most common monosaccharide
Four Levels of Protein Structure ▪Primary structure of a protein is its unique sequence of _____ ________ ▪Secondary structure, found in most proteins, consists of ________ and _______ in the polypeptide chain ▪Tertiary structure is determined by interactions among various ________ chains (R groups) ▪Quaternary structure results when a protein consists of ________ polypeptide chains
▪Primary structure of a protein is its unique sequence of amino acids ▪Secondary structure, found in most proteins, consists of coils and folds in the polypeptide chain ▪Tertiary structure is determined by interactions among various side chains (R groups) ▪Quaternary structure results when a protein consists of multiple polypeptide chains
Proteins include a diversity of structures, resulting in a wide rangeof functions ▪Proteins account for more than _____% of the dry mass of most cells ▪Some proteins speed up chemical reactions ▪Other protein functions include _________, storage, ___________, cellular _______________, movement, or structural support
▪Proteins account for more than 50% of the dry mass of most cells ▪Some proteins speed up chemical reactions ▪Other protein functions include defense, storage, transport, cellular communication, movement, or structural support
▪Proteins are all constructed from the same set of _____ amino acids ▪Polypeptides are ___________ polymers built from these amino acids ▪A Protein is a biologically functional molecule that consists of one or more polypeptides
▪Proteins are all constructed from the same set of 20 amino acids ▪Polypeptides are unbranched polymers built from these amino acids ▪A Protein is a biologically functional molecule that consists of one or more polypeptides
DNA and Proteins as Tape Measures of Evolution ▪Sequences of genes and their __________ products document the hereditary background of an organism ▪Linear sequences of DNA molecules are passed from parents to offspring ▪We can extend the concept of "molecular genealogy" to relationships between __________ ▪Molecular biology has added a new measure to the toolkit of _____________ biology
▪Sequences of genes and their protein products document the hereditary background of an organism ▪Linear sequences of DNA molecules are passed from parents to offspring ▪We can extend the concept of "molecular genealogy" to relationships between species ▪Molecular biology has added a new measure to the toolkit of evolutionary biology
Storage Polysaccharides-Plants ▪___________, a storage polysaccharide of plants, consists entirely of _________ monomers ▪Plants store surplus starch as ____________ within chloroplasts and other plastids (for energy/carbon) ▪The simplest form of starch is _____________
▪Starch, a storage polysaccharide of plants, consists entirely of glucose monomers ▪Plants store surplus starch as granules within chloroplasts and other plastids ▪The simplest form of starch is amylose
Steroids ▪Steroids are lipids characterized by a ________ ___________ consisting of ___________ fused rings ▪Cholesterol, a type of steroid, is a component in ___________ cell membranes and a precursor from which other steroids are synthesized ▪A high level of cholesterol in the blood may contribute to cardiovascular disease •Many of these other steroids are hormones, including the vertebrate sex hormones. •Although cholesterol is an essential molecule in animals, high levels of cholesterol in the blood may contribute to cardiovascular disease. •Both ___________ fats and ________ fats exert their negative impact on health by affecting cholesterol levels.
▪Steroids are lipids characterized by a carbon skeleton consisting of four fused rings ▪Cholesterol, a type of steroid, is a component in animal cell membranes and a precursor from which other steroids are synthesized ▪A high level of cholesterol in the blood may contribute to cardiovascular disease •Many of these other steroids are hormones, including the vertebrate sex hormones. •Although cholesterol is an essential molecule in animals, high levels of cholesterol in the blood may contribute to cardiovascular disease. •Both saturated fats and trans fats exert their negative impact on health by affecting cholesterol levels.
Nucleic acids store, transmit, and help express hereditary information ▪The amino acid sequence of a polypeptide is programmed by a unit of inheritance called a ________ ▪Genes consist of DNA, a __________ _____made of monomers called nucleotides
▪The amino acid sequence of a polypeptide is programmed by a unit of inheritance called a gene ▪Genes consist of DNA, a nucleic acid made of monomers called nucleotides
▪The major function of fats is ____________ ____________ ▪Humans and other mammals store their long-term food reserves in ___________ cells ▪Adipose tissue also cushions vital organs and ____________ the body
▪The major function of fats is energy storage ▪Humans and other mammals store their long-term food reserves in adipose cells ▪Adipose tissue also cushions vital organs and insulates the body
Structural Polysaccharides -Plants ▪The polysaccharide ___________ is a major component of the tough wall of plant cells ▪Like starch, cellulose is a polymer of glucose, but the _____________ _______________ differ ▪The difference is based on two ring forms for glucose: __________ and ____________
▪The polysaccharide cellulose is a major component of the tough wall of plant cells ▪Like starch, cellulose is a polymer of glucose, but the glycosidic linkages differ ▪The difference is based on two ring forms for glucose: alpha (α) and beta (β)
Protein Structure and Function ▪The specific activities of proteins result from their intricate three-dimensional architecture ▪A functional protein consists of one or more polypeptides precisely twisted, folded, and coiled into a unique shape
▪The specific activities of proteins result from their intricate three-dimensional architecture ▪A functional protein consists of one or more polypeptides precisely twisted, folded, and coiled into a unique shape