BIOS 1107 Module 2: Macromolecules IKE & TICA, Questions with accurate answers. Graded A

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BIOS 1107 Module 2: Macromolecules IKE & TICA, Questions with accurate answers. Graded A What defines a chemical element? - ✔✔the number of protons in the nucleus of the atom Match the typ... e of bond with its description - ✔✔1. nonpolar covalent- electrons are shared equally between two atoms 2. ionic bond- electrostatic attraction between ions of opposite charge 3. polar covalent bond- electrons are shared equally between two atoms by unequally 4. hydrogen bond- weak electrostatic attraction involving a hydrogen atom with a weak positive charge and an electronegative atom with a weak negative charge All chemical reactions between atoms involves - ✔✔only the valence electrons Compounds that have mostly nonpolar covalent bonds between atoms are - ✔✔hydrophobic (do not dissolve well in water) Which of the following statements are true about water molecules? - ✔✔water molecules are dipoles, water molecules form extensive hydrogen bonds with each other, water molecules form hydrogen bonds with ions and molecules with polar covalent bonds Which of the following is not one of the six major elements that make up biological macromolecules? - ✔✔calcium (hydrogen, sulfur, phosphorous, and nitrogen make up macromolecules) Which of the molecules is (are) organic? - ✔✔formic acid and methane What cellular macromolecules contain large amount of phosphorous? - ✔✔membrane lipids and nucleic acids Match the monomer or subunit to the polymer - ✔✔1. amino acids- proteins 2. monosaccharides - polysaccharides 3. nucleotides- nucleic acids If a cell is fed radioactive phosphate in the culture medium, what macromolecules will become highly radioactive? Select all that apply. - ✔✔membrane lipids, DNA, and RNA A molecule that is composed primarily of just carbon and hydrogen is most likely - ✔✔a lipid Which of the following is/are only defined by shared physical properties (rather than a polymer defined by shared chemical structure) - ✔✔Lipids Which of the following biomolecules is/are primarily linear molecules composed of repeating subunits and exhibiting polarity? - ✔✔DNA, RNA, and proteins Match the bond type with the related macromolecule - ✔✔1. peptide bond- protein 2. phosphodiester bond- nucleic acid 3. glycosidic bond- polysaccharide Which of the following is true of RNA vs. DNA - ✔✔none of these are correct (both DNA and RNA are double stranded, both have four nucleotides) Which of the following is/are NOT true of dehydration/condensation reactions? - ✔✔a dehydration reaction results in destruction of a water molecule and a condensation reaction is the same as a hydrolysis reaction Match the glycan molecule function wit the type of glycosidic linkage - ✔✔storage- alpha-1,4 structure- beta-1,4 Match the level of protein structure with the bonds responsible for stabilizing - ✔✔1. primary - covalent bonds between sequential amino acids 2. secondary - hydrogen bonds between peptide backbone 3. tertiary - hydrogen bonds, hydrophobic interactions, van der Waals, covalent, and ionic bonds between R groups and peptide backbone 4. quaternary - hydrogen bonds, hydrophobic interactions, van der Waals, covalent , and ionic bonds between multiple polypeptides In what part of a protein would you expect to find a hydrophobic amino acid like tryptophan - ✔✔In the interior of a globular (free-floating) protein and In the part of a membrane-bound protein that interacts with membrane lipids Hemoglobin aggregates in sickle cell disease due to a mutation that changes a specific glutamate (Glu) to a valine (Val), . What would you expect in the case of a Glu to aspartate (Asp) mutation? The structures of these amino acids are shown below: - ✔✔A change in primary structure and Little or no effect on three-dimensional structure Organic extractions separate molecules according to their polarity. Polar molecules stay in the aqueous phase, whereas non-polar molecules dissolve in the organic solvent phase. When cells are broken (lysed) and extracted with organic solvents, which of these molecules will be dissolved in the aqueous (water) phase? Select all that apply. - ✔✔nucleic acids, carbohydrates, and small charged and polar molecules If an organism is treated with a drug that inhibits polysaccharide synthesis, what function(s) would be affected? - ✔✔shape/structural integrity, energy storage, and cell to cell signaling/recognition What is true about all lipids in all cells? - ✔✔they do not dissolve in water Some membrane lipids are characteristic of only one of the 3 domains of cellular life. Match the domain of life with the membrane lipid their cell membranes contain. - ✔✔1. Archaea - ether-linked isoprenoid chains 2. Bacteria - ester-linked fatty acid chains and hopanoids 3. Eukarya - ester-linked fatty acid chains and sterols Cell membranes are lipid bilayers, consisting of an outer leaflet facing the outside of the cell and an inner leaflet interacting with the cytoplasm. Can phospholipids spontaenously flip from the outer face to the inner face, and vice versa, with no assistance from membrane proteins? - ✔✔no A fish cell membrane will be more fluid at low temperatures if it contains - ✔✔more cis-unsaturated and polyunsaturated fatty acids Brand X margarine melts at room temperature, while Brand Y stays solid. Brand Y probably has - ✔✔both more hydrogenated fatty acids and more trans-unsaturated fatty acids Prokaryotes differ from eukaryotes in which of the following ways? - ✔✔prokaryotic cells are generally smaller than eukaryotic cells and prokaryotes have circular chromosomes Which of these eukaryotic organelles is NOT part of the endomembrane system, nor derived from the endomembrane system? - ✔✔mitochondria and chloroplasts (includes golgi, rough ER, smooth ER, nuclear envelope, lysosomes, plasma membrane) In a eukaryotic cell, secreted proteins and integral plasma membrane proteins are synthesized by___ - ✔✔ribsomes docked to the rough ER A protein synthesized on cytoplasmic ribosomes may function in - ✔✔the cytoplasm, the mitochondria, and the nucleus (not in the plasma membrane) Which of these processes occur in the nucleus? - ✔✔DNA replication and transcription of DNA to RNA A major cause of coral bleaching in recent years has been warmer ocean temperatures. The membranes of the photosynthetic algal symbiont appears particularly sensitive to increase in temperature. At higher temperatures, membranes with a given lipid composition will become _____ - ✔✔more fluid, and more leaky Figure 1 shows the % of C-18 fatty acids that are unsaturated (have one or more double bonds between carbons), in lipids extracted from algal cells cultured at different temperatures over 4 weeks. The algal cells grown at higher temperatures decrease their percentage of unsaturated fatty acids over time. How will decreasing the percentage of unsaturated fatty acids change the properties of the algal membranes? - ✔✔their membranes will be more rigid and less leaky Symbiodinium are eukaryotes. What other lipids would they have in their membranes? Select all that apply - ✔✔sterols and cholesterol and sphingolipids In response to heat stress, you might also expect the amount of cholesterol in the algal plasma membranes to: - ✔✔increase If an algal cell isolated from seawater is transferred to fresh water, the algal cell will initially - ✔✔absorb water and increase in volume The passage of water molecules across cell membranes through aquaporins is an example of: - ✔✔facilitated diffusion CFTR is a plasma membrane protein with multiple transmembrane domains. In what cellular compartment will the CFTR protein be synthesized? - ✔✔rough endoplasmic reticulum Which of these molecules, if radioactively labeled, will be incorporated into newly made CFTR protein? - ✔✔amino acids What radioisotope could you use to label newly synthesized CFTR protein, but not lipids, carbohydrates or nucleic acids? - ✔✔35S Where would newly synthesized CFTR accumulate if formation of secretory vesicles was disrupted? - ✔✔secretory vesicles [Show More]

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