Phys Exam 2-1

  1. What are the basic characteristics of cells
    • smallest living subdivision of human body
    • diverse in structure and physiology
    • divided into organelles
    • -isolation of chemical reactions
    • -each organelle performs a specific function
  2. Three primary regions of cell
    • plasma membrane
    • cytoplasm
    • nucleus
  3. components/functions of plasma membrane?
    • outer boundary of cell
    • seperates intracellular enviro from extracellular enviro
    • regulates movement of materials into and out of cell
    • -a selective barrier
    • -helps maintain internal cell homeostasis
  4. plasma membrane structure?
    • composed of lipids, proteins, and carbohydrates
    • -arranged in bilayer of phospholipids with proteins suspended
    • -"fluid mosaic model"
  5. amphipathic molecules
    polar heads face extracellular fluid and cytoplasm

    nonpolar tails prevent random movement across the membrane
  6. microvilli
    • found on apical surface of some hollow tube like organs
    • fingerlike projections
    • increase surface area
    • facilitate movement of materials between intra and extracellular fluids
  7. cilia
    projects into extracellular fluid

    contains microtubules, and uses ATP

    capable of movement and generates flow
  8. cytosol
    semi liquid, gel like-has a water solvent

    surrounds organelles

    contains various disolved materials, enzymes, etc
  9. cytosol functions
    location for metabolic reactions

    protein synthesis

    storage of fat, glycogen, and secretory vesicles
  10. cytoskeleton
    • network of protein fibers in cytosol
    • -microtubules
    • -microfilaments
  11. cytoskeleton functionsstry
    structual support and shape of cell

    movement of materials inside the cell

    • -external movement
    • cilia and flagella
    • amoeboid movement
    • endocytosis and exocytosis(secretion)
  12. lysosomes
    membrane bound organelle with digestive enzymes

    break down large molecules(cells digestive system)

    destroy bacteria, old organelles
  13. mitochondria
    • surrounded by two cell membranes
    • -inner membrane cristae and surrounds the matrix

    posses own DNA

    • power generators of cell
    • -produces ATP using energy released from the breakdown of food
  14. ribosomes
    large protein-RNA complexes

    found free floating in cytosol or attached to ER

    synthesizes proteins based on triplets of mRNA molecules
  15. RER
    Production of Protein

    coated with ribosomes on cytosolic side

    • synthesizes proteins for;
    • cell membranes
    • lysosomes
    • export of the cell
  16. smooth ER
    No protein synthesis

    No ribosomes
  17. smooth ER functions
    lipid synthesis

    Ca+ storage and release

    metabolize various molecules
  18. golgi complex
    • stacks of flattened sacs(cisternae)
    • Functions:
    • posttranslational modifications(finishing steps)

    • sort and direct finished products to final destinations
    • "directs traffic"
  19. vesicles
    small membrane-enclosed chambers used to transport material within the cell

    • -delivers membrane molecules
    • -fluid within vesicle can be emptied into another organelle(lysosomes) or secreted into extracellular fluid(secretory vesicles)
  20. nucleus
    control center-contains info for protein synthesis

    surrounded by double membrane(nuclear envelope) with nuclear pores open to cytosol

    • contains chromatin
    • -DNA and assoc proteins
    • -chromosome= strand of DNA
    • nucleolus-synthesis of RNA
  21. genes
    sequences of DNA containing info for amino acid sequence to make proteins
  22. genome
    the total of all the genes in the human body(approx 25,000)
  23. proteome
    all the different proteins produced in the human body(approx 100,000)
  24. Note!
    genes can encode for more than one protein

    not all genes in a genome are active (approx 300)

    different types of cells express different sets of genes within the person's genome
  25. DNA to RNA
  26. mRNA
    encodes the structure for a particular protein

    "reads the code on DNA"
  27. tRNA
    carries amino acids to ribosomes to add into newly synthesized polypeptide
  28. rRNA
    structural component of ribosomes

    produced in nucleolus
  29. From RNA to protein

    mRNA sequence read by ribosomes to generate a protein with a specific amino acid sequence

    -ribosome binds to mRNA

    -ribosomes reads triplets(codons)

    -tRNA delivers specific amino acids

    -amino acid is transferred from the tRNA to polypeptide chain

    -ribosome reads next codon and repeats process

    -polypeptide becomes protein
  30. DNA replication
    DNA must be copied before cell division

    double helix seperated

    each strand used as template to synthesize new copy
  31. Mitosis Stages
    • Interphase-what a cell is in most of the time
    • the nucleus is visible

    Prophase-the centrioles move apart and spindle fibers are formed.

    Metaphase-chromosomes are lined up at the equator

    Anaphase-the centromeres split to opposite polls

    Telephase- cell division nearly complete
  32. 2 forms of cell death
    necrosis- pathological cell death(i.e. disease)

    • apoptosis- homeostatic cell death
    • -cells die off in controlled fashion that does not damage adjacent cells

    -signals received by target cell activate specific enzymes(caspases) which fragment DNA and disassemble organelles
  33. metabolism
    • all chemical reactions occuring in a living organism
    • -breakdownn of some substances

    -build up of other substances

    -requires enzymes to catalyze reactions
Card Set
Phys Exam 2-1
review of cell and tissue anatomy