Campbell Biology Ch4+5

Carbon's ability to form four bonds allows for a vast diversity of organic compounds, enabling the complexity of life.

Harold Urey concluded that abiotic synthesis of organic compounds could occur, suggesting a possible pathway for the origin of life.

A carbon atom bonded to four atoms has a tetrahedral shape, forming a pyramid structure.

<p>Hydrocarbons, though not abundant in living organisms, store high amounts of energy due to their numerous nonpolar bonds.</p> Signup and view all the answers

<p>Structural isomers differ in the covalent arrangement of atoms, while cis-trans isomers differ in the spatial arrangement around a double bond.</p> Signup and view all the answers

<p>The number of isomers increases dramatically with larger carbon skeletons, with hundreds or thousands of variants possible.</p> Signup and view all the answers

<p>Carbon dioxide is often excluded from the definition of organic compounds since it does not contain hydrogen and lacks traditional carbon bonding.</p> Signup and view all the answers

<p>Carbon skeletons are chains of carbon atoms that form the backbone of organic molecules, providing structure and functional versatility.</p> Signup and view all the answers

<p>Cis-trans isomerism occurs because double bonds restrict rotation, affecting the spatial arrangement of atoms.</p> Signup and view all the answers

<p>Carbon's chemical versatility allows for the formation of a wide variety of complex molecules, which is fundamental to the diversity of life.</p> Signup and view all the answers

<p>Methyl groups serve as tags on biological molecules and are unresponsive to chemical reactions due to being nonpolar.</p> Signup and view all the answers

<p>ATP consists of three phosphate groups, while ADP has only two phosphate groups after one is split off.</p> Signup and view all the answers

<p>Hydrolysis disassembles polymers into monomers, requiring the input of water molecules.</p> Signup and view all the answers

<p>Functional groups are groups of chemicals directly involved in chemical reactions of a molecule, responsible for its characteristics.</p> Signup and view all the answers

<p>All except sulfhydryl groups are hydrophilic, which means they increase the solubility of organic compounds in water.</p> Signup and view all the answers

<p>Polymerization is the process of creating polymers, which are essential for forming macromolecules like proteins and nucleic acids.</p> Signup and view all the answers

<p>Enzymes speed up chemical reactions by lowering the activation energy needed for those reactions to occur.</p> Signup and view all the answers

<p>Monomers are single, repeating units, while polymers are long chains made from multiple monomers linked together.</p> Signup and view all the answers

<p>A dehydration reaction connects monomers by removing a small molecule, typically water, thereby forming polymers.</p> Signup and view all the answers

<p>Differences in macromolecule diversity, particularly in DNA and proteins, can indicate the genetic distance between organisms.</p> Signup and view all the answers

<p>Both hormones are structurally similar but differ by the chemical groups attached, which determines their specific roles in sexual characteristics.</p> Signup and view all the answers

<p>A condensation reaction connects monomers, releasing a small molecule such as water as a byproduct.</p> Signup and view all the answers

<p>ATP does not store energy in a static form; rather, it has the potential to release energy when one phosphate group is hydrolyzed.</p> Signup and view all the answers

<p>Ribose is the sugar component of ATP that connects the adenosine to the three phosphate groups.</p> Signup and view all the answers

<p>Saturated fats have no double bonds between carbon atoms, while unsaturated fats contain one or more double bonds.</p> Signup and view all the answers

<p>Adipose cells store long-term food reserves, cushion vital organs, and provide insulation.</p> Signup and view all the answers

<p>Hydrogenation converts unsaturated fats into saturated fats by adding hydrogen, which can solidify the oil.</p> Signup and view all the answers

<p>A phospholipid is a molecule with two fatty acids and a phosphate group that forms a bilayer, crucial for cell membrane structure.</p> Signup and view all the answers

<p>Cholesterol contributes to the fluidity of cell membranes and is a precursor for steroid hormones.</p> Signup and view all the answers

<p>Trans fats form during the hydrogenation of unsaturated fats, resulting in unique double bond structures that contribute to heart disease.</p> Signup and view all the answers

<p>Fats can store twice as much energy per gram compared to polysaccharides like starch.</p> Signup and view all the answers

<p>Lipid molecules are mainly hydrophobic due to their nonpolar C-H bonds and minimal polar components.</p> Signup and view all the answers

<p>Unsaturated fats have double bonds that cause kinks in their hydrocarbon chains, preventing tight packing.</p> Signup and view all the answers

<p>A diet high in saturated fats can lead to cardiovascular diseases like atherosclerosis.</p> Signup and view all the answers

<p>Ester linkages are formed when fatty acids bond with glycerol during fat synthesis, essential for fat structure.</p> Signup and view all the answers

<p>'Cis' double bonds cause bends in the fatty acid chain, while 'trans' double bonds do not, leading to straighter structures.</p> Signup and view all the answers

<p>High cholesterol levels can lead to plaque formation in blood vessels, increasing the risk of atherosclerosis.</p> Signup and view all the answers

<p>Triglycerides are fats formed from one glycerol molecule and three fatty acids linked by ester linkages.</p> Signup and view all the answers

<p>Hydrogen bonds form between every fourth amino acid, stabilizing the helical shape of the protein.</p> Signup and view all the answers

<p>The 𝝱 pleated sheet comprises two or more polypeptide segments lying side by side, connected by hydrogen bonds.</p> Signup and view all the answers

<p>Tertiary structure refers to the overall three-dimensional shape stabilized by side chain interactions, while secondary structure involves interactions between backbone constituents.</p> Signup and view all the answers

<p>Hydrophobic interactions cause nonpolar amino acids to cluster at the protein core, minimizing their contact with water.</p> Signup and view all the answers

<p>Disulfide bridges form between cysteine side chains, stabilizing the protein's structure by linking different parts of the polypeptide chain.</p> Signup and view all the answers

<p>Quaternary structure involves the assembly of two or more polypeptide chains into a functional protein, such as hemoglobin.</p> Signup and view all the answers

<p>Sickle cell disease results from a substitution of valine for glutamic acid at the sixth amino acid in hemoglobin's primary structure.</p> Signup and view all the answers

<p>Folding is influenced by the crowded cellular environment and is aided by other proteins that assist in the process.</p> Signup and view all the answers

<p>Cis isomers have substituents on the same side of a double bond, while trans isomers have them on opposite sides.</p> Signup and view all the answers

<p>One enantiomer often exhibits a different level of effectiveness or activity in biological systems compared to its counterpart.</p> Signup and view all the answers

<p>An asymmetric carbon atom is one that is bonded to four different atoms or groups.</p> Signup and view all the answers

<p>Structural isomers vary in the covalent arrangement of their atoms, which can include differences in carbon skeleton shape and the position of double bonds.</p> Signup and view all the answers

<p>Double bonds restrict the free rotation of atoms, whereas single bonds allow for rotation.</p> Signup and view all the answers

<p>Carbon has four valence electrons, allowing it to form stable covalent bonds with many different elements and create extensive chains or rings.</p> Signup and view all the answers

<p>Hydrocarbons are organic compounds consisting exclusively of carbon and hydrogen atoms, primarily found in fossil fuels like petroleum.</p> Signup and view all the answers

<p>Functional groups are responsible for the chemical reactions and properties of a molecule, determining its reactivity and interaction with other substances.</p> Signup and view all the answers

<p>Enantiomers are mirror images of each other and cannot be superimposed, much like left and right hands.</p> Signup and view all the answers

<p>Carbon dioxide is essential for photosynthesis, as plants convert it into glucose and oxygen.</p> Signup and view all the answers

<p>Trans fats are a type of unsaturated fat where the hydrogen atoms are on opposite sides of a double bond, leading to different health impacts compared to cis fats.</p> Signup and view all the answers

<p>These four free slots enable carbon to form four stable covalent bonds, allowing for diverse molecular structures.</p> Signup and view all the answers

<p>Different isomers may have drastically different effects in biological reactions, sometimes leading to significant variations in organism responses.</p> Signup and view all the answers

<p>Estradiol and testosterone have similar structures but differ in their attached chemical groups, which determine their distinct roles in sexual characteristics.</p> Signup and view all the answers

<p>Animals expend more energy than plants, so they store energy in fats rather than starch.</p> Signup and view all the answers

<p>Adipose cells store long-term food reserves and cushion vital organs while also providing insulation.</p> Signup and view all the answers

<p>Phospholipids form a bilayer where hydrophilic heads face outward and hydrophobic tails face inward.</p> Signup and view all the answers

<p>Steroids consist of a carbon skeleton with four fused rings and serve important roles, such as being components of cell membranes and precursors for hormones.</p> Signup and view all the answers

<p>Enzymes speed up chemical reactions and regulate metabolism by acting as catalysts.</p> Signup and view all the answers

<p>A polypeptide is a polymer of amino acids formed by peptide bonds through dehydration reactions.</p> Signup and view all the answers

<p>The 'R' group determines the properties of each amino acid, influencing hydrophobicity or charge.</p> Signup and view all the answers

<p>Primary structure is the linear sequence of amino acids, while secondary structure involves coiling and folding stabilized by hydrogen bonds.</p> Signup and view all the answers

<p>Globular proteins are spherical and often function as enzymes, while fibrous proteins are long and provide structural support.</p> Signup and view all the answers

<p>The amino acid sequence dictates how the polypeptide will fold and arrange itself in three-dimensional space.</p> Signup and view all the answers

<p>A peptide bond is a covalent bond formed between the amino group of one amino acid and the carboxyl group of another through a dehydration reaction.</p> Signup and view all the answers

<p>High cholesterol levels can lead to atherosclerosis, which increases the risk of heart disease.</p> Signup and view all the answers

<p>A protein's structure, including its shape and charge distribution, dictates its binding capabilities.</p> Signup and view all the answers

<p>Proteins have primary (amino acid sequence), secondary (coils and folds), tertiary (3D shape), and quaternary (multiple polypeptides) structures.</p> Signup and view all the answers

<p>Hydrogen bonds primarily stabilize the secondary structure of proteins.</p> Signup and view all the answers

<p>Carbohydrates are primarily composed of carbon, hydrogen, and oxygen.</p> Signup and view all the answers

<p>Hydrophobic interactions cause nonpolar amino acids to cluster at the core of the protein, away from water.</p> Signup and view all the answers

<p>The tertiary structure is stabilized by interactions between the side chains and amino acid groups, including hydrogen and ionic bonds.</p> Signup and view all the answers

<p>Glucose serves as a key energy source that is broken down to release energy for cellular activities.</p> Signup and view all the answers

<p>Starch consists of glucose monomers with 1-4 glycosidic linkages in the same orientation, while cellulose has alternating orientations of its hydroxyl groups.</p> Signup and view all the answers

<p>Quaternary structures are characterized by the association of two or more polypeptide chains that form a functional protein.</p> Signup and view all the answers

<p>Glucose and fructose are structural isomers, differing in their arrangement of atoms despite having the same chemical formula.</p> Signup and view all the answers

<p>α-helices are coiled structures stabilized by hydrogen bonds between every fourth amino acid, whereas β-pleated sheets consist of segments lying side by side connected by hydrogen bonds.</p> Signup and view all the answers

<p>Disaccharides are carbohydrates composed of two monosaccharides linked by a covalent bond; an example is lactose.</p> Signup and view all the answers

<p>Sickle cell disease is caused by a substitution of valine for glutamic acid at the sixth position of the primary structure of hemoglobin.</p> Signup and view all the answers

<p>A glycosidic linkage is a covalent bond formed between two monosaccharides through a dehydration reaction.</p> Signup and view all the answers

<p>Van der Waals interactions help hold nonpolar amino acids together when they cluster in the protein's core.</p> Signup and view all the answers

<p>The crowded cellular environment aids in protein folding by promoting interactions between polypeptide chains and other proteins.</p> Signup and view all the answers

<p>Cellulose is indigestible because the enzymes that hydrolyze starch cannot break the unique glycosidic linkages in cellulose.</p> Signup and view all the answers

<p>Chitin serves as a structural polysaccharide, providing strength and support in the exoskeletons of arthropods.</p> Signup and view all the answers

<p>Saturated fats contain no double bonds between carbon atoms, making them solid at room temperature, while unsaturated fats have one or more double bonds and are typically liquid.</p> Signup and view all the answers

<p>The size of the carbon skeleton in sugars ranges from 3 to 7 carbons, influencing their classification and functional properties.</p> Signup and view all the answers

<p>Plants transport carbohydrates primarily in the form of sucrose, which consists of glucose and fructose bonded together.</p> Signup and view all the answers

<p>Pentoses and hexoses tend to form ring structures because this conformation is the most stable for these sugars.</p> Signup and view all the answers

<p>Glycogen is a highly branched polysaccharide composed of glucose and functions primarily as an energy storage molecule in animals.</p> Signup and view all the answers

<p>Fats are termed hydrophobic because they do not mix well with water due to their nonpolar nature.</p> Signup and view all the answers

<p>Denaturation is the process where proteins lose their shape and biological activity due to changes in pH, temperature, or salt concentration.</p> Signup and view all the answers

<p>The polypeptide chains fold based on the properties of the surrounding environment, such as solvent polarity, which influences the orientation of hydrophobic and hydrophilic regions.</p> Signup and view all the answers

<p>Weak chemical bonds, such as hydrogen bonds and ionic bonds, are crucial for stabilizing the various shapes proteins adopt during folding.</p> Signup and view all the answers

<p>Some proteins can renature when the denaturing agent is removed if their primary structure remains intact, but others, like cooked egg proteins, cannot.</p> Signup and view all the answers

<p>X-ray crystallography is used to determine the three-dimensional structure of proteins by analyzing how X-rays diffract through crystallized molecules.</p> Signup and view all the answers

<p>Intrinsically disordered proteins lack a fixed three-dimensional structure until they interact with other molecules, which is critical for their flexibility and functionality.</p> Signup and view all the answers

<p>Enzymes rely on their specific three-dimensional structure to interact with substrates, facilitating chemical reactions efficiently.</p> Signup and view all the answers

<p>A polypeptide is a chain of amino acids, whereas a functional protein is one or more polypeptides folded into a specific three-dimensional shape.</p> Signup and view all the answers

<p>Each structure level contributes to the overall shape and stability of the protein, which dictates its ability to perform specific biological functions.</p> Signup and view all the answers

<p>A peptide bond forms when the carboxyl group of one amino acid reacts with the amino group of another, releasing a water molecule in a dehydration reaction.</p> Signup and view all the answers

<p>Diseases such as cystic fibrosis, Alzheimer's, Parkinson's, and mad cow disease are linked to the accumulation of misfolded proteins.</p> Signup and view all the answers

<p>Secondary protein structures are stabilized primarily by hydrogen bonds between the backbone atoms of the polypeptide.</p> Signup and view all the answers

<p>Catalysts, primarily enzymes, accelerate chemical reactions in biological systems, making them essential for metabolism.</p> Signup and view all the answers

<p>Denaturation refers to the process where proteins lose their shape and become biologically inactive due to alterations in environmental factors like pH, salt concentration, or temperature.</p> Signup and view all the answers

<p>High temperatures can lead to denaturation of proteins, causing them to lose their functional shape, which can disrupt critical biological processes.</p> Signup and view all the answers

<p>The primary structure of proteins is defined by the specific sequence of amino acids in a polypeptide chain, which ultimately determines the protein's three-dimensional shape and function.</p> Signup and view all the answers

<p>Ribosomes facilitate the translation of mRNA into polypeptides, which are then folded into functional proteins.</p> Signup and view all the answers

<p>Purines consist of a six-membered ring fused to a five-membered ring, while pyrimidines are composed of a single six-membered ring.</p> Signup and view all the answers

<p>The sugar-phosphate backbone is essential for maintaining the structural stability of nucleic acids and provides directionality to the polynucleotide chain.</p> Signup and view all the answers

<p>Antiparallel arrangement refers to the opposite orientation of the two strands of DNA, where one strand runs 5’ to 3’ while the other runs 3’ to 5’.</p> Signup and view all the answers

<p>Gene expression is the process through which genetic information in DNA is transcribed into mRNA and translated into proteins, controlling various cellular functions.</p> Signup and view all the answers

<p>X-ray crystallography is the technique used to determine the three-dimensional structure of proteins by analyzing the diffraction of X-rays through crystallized molecules.</p> Signup and view all the answers

<p>Environmental changes, such as temperature and chemical concentration alterations, can disrupt the delicate interactions that stabilize protein folding, leading to misfolding.</p> Signup and view all the answers

<p>RNA is typically single-stranded and contains ribose sugar, while DNA is double-stranded and contains deoxyribose sugar.</p> Signup and view all the answers

<p>Phosphodiester linkages bond nucleotides together in a polynucleotide strand, forming the backbone of nucleic acids through covalent bonds between the sugar of one nucleotide and the phosphate of another.</p> Signup and view all the answers

<p>Nucleotide polymerization involves the linkage of nucleotides into polynucleotides through the loss of phosphate groups, forming nucleotide sequences encoded by genetic information.</p> Signup and view all the answers

<p>Base pairs in DNA contribute to stability through hydrogen bonds between complementary bases (A-T and G-C), which help hold the two DNA strands together.</p> Signup and view all the answers