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Indietro

CHAPTER 3 Biology in Focus

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Termini in questo insieme (29)

  • What is an organic compound?
    A compound containing carbon, which is the basis of most molecules in living organisms.
  • Name the four main classes of important biological molecules.
    Carbohydrates, lipids, proteins, and nucleic acids.
  • What is a polymer?
    A long molecule consisting of many similar building blocks called monomers.
  • What reaction links monomers to form polymers?
    A dehydration reaction, which removes a water molecule to form a covalent bond.
  • What reaction breaks down polymers into monomers?
    Hydrolysis, which adds a water molecule to break covalent bonds.
  • What are monosaccharides?
    The simplest carbohydrates or simple sugars, usually with molecular formulas that are multiples of CH2O.
  • What is a glycosidic linkage?
    A covalent bond formed between two monosaccharides during a dehydration reaction to form a disaccharide.
  • What determines the structure and function of a polysaccharide?
    The type of sugar monomers and the positions of glycosidic linkages.
  • What is the main storage polysaccharide in plants?
    Starch, composed entirely of glucose monomers.
  • What is glycogen?
    A storage polysaccharide in animals, mainly stored in liver and muscle cells.
  • What is cellulose and its role?
    A structural polysaccharide that is a major component of plant cell walls.
  • What are lipids characterized by?
    Having little or no affinity for water; they are hydrophobic due to mostly hydrocarbon content.
  • What are fats made of?
    Glycerol and three fatty acids joined by ester linkages to form triacylglycerols.
  • Difference between saturated and unsaturated fatty acids?
    Saturated fatty acids have no double bonds and maximum hydrogens; unsaturated have one or more double bonds causing kinks.
  • What is the major function of fats?
    Energy storage; fats store more energy per gram than carbohydrates.
  • Describe the structure of phospholipids.
    Two fatty acid tails (hydrophobic) and a phosphate group head (hydrophilic) attached to glycerol.
  • What are steroids?
    Lipids characterized by a carbon skeleton of four fused rings; cholesterol is a key example.
  • What are proteins and their general functions?
    Polymers of amino acids with diverse functions including enzymatic catalysis, defense, transport, signaling, movement, and structural support.
  • What determines a protein's structure and function?
    The unique sequence of amino acids (primary structure) and the folding into 3D shapes.
  • Name the four levels of protein structure.
    Primary (amino acid sequence), secondary (alpha helices and beta sheets), tertiary (3D folding), and quaternary (multiple polypeptides).
  • What causes sickle-cell disease at the molecular level?
    A single amino acid substitution in hemoglobin's primary structure alters its shape and function.
  • What is denaturation?
    Loss of a protein's native structure due to environmental changes, causing loss of function.
  • What are nucleic acids made of?
    Polymers called polynucleotides made of monomers called nucleotides, each with a nitrogenous base, pentose sugar, and phosphate group.
  • Difference between DNA and RNA sugars?
    DNA contains deoxyribose; RNA contains ribose.
  • What are the nitrogenous bases in DNA and RNA?
    DNA: adenine, guanine, cytosine, thymine; RNA: adenine, guanine, cytosine, uracil.
  • How are nucleotides linked in nucleic acids?
    By covalent bonds between the 3' hydroxyl of one sugar and the 5' phosphate of the next, forming a sugar-phosphate backbone.
  • Describe the structure of DNA.
    Two antiparallel polynucleotide strands forming a double helix with complementary base pairing via hydrogen bonds.
  • What is genomics?
    The study and comparison of whole genomes using bioinformatics tools.
  • What is proteomics?
    The large-scale study and analysis of proteins.