physiology chp 2

  1. Which of the following molecules can diffuse directly through the lipid bilayer of cell membranes?

    A. steroid hormones
  2. By definition, biomolecules must _____.

    C. contain carbon
  3. Hydrophobic molecules are _____.

    A. lipophilic
  4. DNA is _______________ into RNA.

    C. transcribed
  5. Which of the following may be found in cell membranes?

    E. all of the above
  6. Protein synthesis requires the participation of which of the following organelles?

    C. nucleus
  7. A protein is coded in the DNA by a _____.

    B. gene

    Only the sense strand of DNA codes for a protein.
  8. Direct electrical and metabolic coupling between cells is facilitated by _____.

    B. gap junctions 

    Coupling between cells requires a direct pathway for the transfer of ions or other molecules.
  9. DNA replication occurs during which phase of the cell cycle?

    A. S
  10. Cell division can be divided into two phases: ___________ and cytokinesis.

    D. mitosis 

    Anaphase and telophase are phases within mitosis. Interphase is the period between cell divisions.
  11. Starch is a polysaccharide found in animal tissue.

    a. True 
    b. False
    b. False
  12. In RNA, adenine forms covalent bonds with thymine.  

    a. True 
    b. False
    b. False
  13. Fibrous proteins are often structural elements in cells.  

    a. True 
    b. False
    a. True
  14. Mitochondrial DNA is inherited through the maternal line.  

    a. True
    b. False
    a. True
  15. Skin and muscle cells contain large numbers of intermediate filaments.  

    a. True 
    b. False
    a. True
  16. The cell membrane is considered to be fluid because the phospholipids and other molecules in the membrane are not linked by chemical bonds.  

    a. True 
    b. False
    a. True
  17. A functional protein is translated from introns joined together in an mRNA molecule.  

    a. True 
    b. False
    a. False
  18. The first amino acid of a protein is always glutathione.  

    a. True 
    b. False
    b. False
  19. A protein without a leader sequence will remain in the nucleus after translation.  

    a. True 
    b. False
    b. False
  20. In contrast to DNA, mRNA molecules tend to be short-lived.  

    a. True 
    b. False
    a. True
  21. desmosome
    filamentous junction between two adjacent cells that provides a strong physical linkage between them; enables tissues to withstand stretching without cells being torn apart from one another
  22. disaccharide
    carbohydrate consisting of two monosaccharides covalently bonded together
  23. eicosanoids
    modified fatty acids (all derived from arachidonic acid) that function in intercellular communication
  24. endoplasmic reticulum
    elaborate network of membranes inside cells that enclose a single interior compartment; includes rough endoplasmic reticulum and smooth endoplasmic reticulum
  25. fatty acids
    long hydrocarbon chains with a carboxyl group at on end
  26. gap junctions
    areas where two adjacent cells are connected together by membrane proteins called connexons that form small channels between the cells, enabling ions and small molecules to move freely between them
  27. gene
    section of DNA that codes for a particular protein or proteins
  28. genetic code
    the correspondence between DNA triplets and specific amino acids that governs the expression of all genetic information
  29. golgi apparatus
    an organelle consisting of membrane-bound flattened sacs called cistern that process molecules synthesized in the endoplasmic reticulum and prepare them for transport
  30. glycogen
    a glucose polymer found in animal cells; functions as an energy store
  31. glycerol
    three-carbon alcohol that functions as the backbone of a triglyceride or phospholipid
  32. glucose
    most common monosaccharide; provides important source of cellular energy
  33. helicase
    enzyme that causes a section of DNA to unwind during replication
  34. hydrolysis
    use of water to split another molecule
  35. interphase
    period in the life cycle of the cell during which it is carrying on its normal physiological functions
  36. intermediate filaments
    fibrous proteins with a diameter between that of microfilaments and microtubules; stronger and more stable than microfilaments
  37. integral membrane proteins
    proteins that are tightly embedded within the lipid bilayer
  38. inclusions
    cytosolic particles composed of triglycerides or glycogen; serve as energy stress for cellular metabolism
  39. law of complementary base pairing
    • states that whenever two strands of nucleic acids are held together by hydrogen bonds,
    • G-C, A-T in DNA (A-U in RNA)
  40. leader sequence
    initial sequence of amino acids that is present in a newly synthesized polypeptide chain and function in directing the fate of the final protein
  41. lipids
    biomolecules that contain primarily carbon and hydrogen atoms linked together by non polar covalent bonds
  42. lysosomes
    small spherical membrane-bound organelles congaing numerous degradative enzymes; involved in the breakdown of unneeded intracellular material or foreign matter that has been taken into the cell
  43. microtubules
    the largest-diameter protein filaments of the cytoskeleton, composed of long, hollow tubes made of tubulin
  44. microfilaments
    the smallest-diameter protein filaments of the cytoskeleton
  45. metabolism
    sum of all the chemical reactions that take place in the body
  46. messenger RNA (mRNA)
    molecule that carries genetic information from the nucleus to the cytoplasm; contains the code for the amino acid sequence of a protein
  47. meiosis
    a series of two cell divisions that generate daughter cells (gametes) with half the normal chromosome number; involved in gametogensis
  48. microvilli
    projections of the plasma membrane that increase its surface area; often found in epithelial cells specialized for transport
  49. monosaccharide
    simple sugar composed of a single unit
  50. mitosis
    the type of cell division that yields two daughter cells containing the normal number of chromosomes; necessary for the growth and replacement of cells
  51. mitochondrial matrix
    the innermost compartment in mitochondria, bounded by the inner mitochondrial membrane; contains the krebs cycle enzymes
  52. nuclear envelope
    barrier that separates the nucleus from the cytoplasm; consists of two membranes
  53. nucleotide
    a biomolecule containing one or more phosphate groups, a 5-C carbohydrate, a nitrogenous base; involved in energy exchange and in the storage and transmission of genetic information in cells
  54. nucleic acids
    polymers of nucleotides that function in the storage and expression of genetic information; see DNA and RNA
  55. nuclear pores
    pore in the nuclear envelope that allow selective movement of molecules between the nucleus and cytoplasm
  56. organelles
  57. plasma membrane
  58. phospholipid
  59. peroxisomes
    spherical membrane-bound organelles that function in the degradation of molecules such as amino acids, fatty acids, and toxic foreign matter
  60. promoter sequence
  61. polysaccharide
Card Set
physiology chp 2
cell structure and function