Biol 107

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  1. Polar bond
    A covalent bond between atoms that differ in electronegativity. The shared electrons are pulled closer to the more electronegative atom, making it slightly negative and the other atom slightly positive.
  2. Hydrogen bonds
    A type of weak chemical bond that is formed when the slightly positive hydorgen bond of a polar covalent bond in one molecule is attracted to the slightly negative atom of a polar covalent bond in another molecule or in another region of the same molecule.
  3. Carbohydrates
    • A sugar (monosaccharide) or one of its dimers (diaccharides) or polymers (polysaccharides).
    • Structure or energy storage.
    • chemical formula n(CH2O) where n is 3 to 7 and oxygen is double bonded to carbon
  4. Proteins
    • Structural or mechanical
    • A biologically functional molecule consisting of one or more polypeptides folded and coiled into a specific three-dimensional structure
    • Polymers of the 20 amino acids. An amino & carboxyl group as well as a side chain (R).
  5. Lipids
    • hydrophobic - membranes or energy storage
    • Any of a group of large biological molecules, including fats, phospholipids, and steroids, that mix poorly, if at all, with water.
  6. Nucleic Acids
    • Information transfer
    • A polymer (polynucleotide) consisting of many nucleotide monomers; serves as a blueprint for proteins and, through the actions of proteins, for all cellular activities. The two types are DNA and RNA.
  7. 4 classes of macromolecules that construct a cell
    • Carbohydrates
    • Proteins
    • Lipids
    • Nucleic Acid
  8. Hydrolysis
    A chemical reaction that breaks bonds between two molecules by the addition of water; functions in disassembly of polymers to monomers.
  9. Dehydration
    A chemical reaction in which two molecules become covalently bonded to each other with the removal of a water molecule.
  10. Isomers
    One of several compounds with the same molecular formula but different structures and therefore different properties.
  11. N-terminus
    The amino end of a polypeptide
  12. C-terminus
    The carboxyl end of a polypeptide
  13. Alpha helix
    A coiled region constituting one form of the secondary structure of proteins, arising from a specific pattern of hydrogen bonding between atoms of the polypeptid backbone (not the side chains).
  14. Beta pleated sheet
    One form of the secondary structure of proteins in which the polypeptide chain folds back and forth. Two regions of the chain lie parallel to each other and are held together by hydrogen bonds between atoms of the polypeptide backbone (not the side chain)
  15. Endo-symbiosis
    Mutually beneficial to both partners
  16. Plastid
    One of a family of closely related organelles that includes chloroplasts, chromoplasts, and amyloplasts. Plastids are found in cells of photosynthetic eukaryotes.
  17. Auto-trophs (self-feeding)
    Make their own complex marcromolecules using inorganic sources of carbon such as CO2
  18. Heterotrophs (different foods)
    Use existing organic sources of carbon to build or derive their macromolecules
  19. Cell membranes
    Amphipathic phospholipids form a bilayer, they are not connected so they can move around and are thus called "fluid", have proteins imbedded. Fluidity is altered by temperature, bends in fatty acid tails, and chlolesterol. They are semi-permeable in that they allow in small, non-charged molecules, small polar molecules, but no large molecules or single ions.
  20. Passive Transport
    The diffusion of a substance across a biological membrane with no expenditure of energy down a concentration gradient.
  21. Osmosis
    The diffusion of free water across a selectively permeable membrane
  22. Active Transport
    The movement of a substance across a cell membrane against its concentrationor electrochemical gradient, mediated by specific transport proteins and requiring an expenditure of energy.
  23. ATP
    The main currency of work or energy in the cells.
  24. Exocytosis
    The cellular secretion of biological molecules by the fusion of vesicles containing them with the plasma membrane
  25. Lipopolysaccharides (LPS)
    • A modification to the outer membrane of gram negative bacteria, they are a long chain of carbohydrates that our immune system detechs as a threat.
    • Lipids and sugars
  26. Endospore
    Used by some bacteria to survive lack of food or harsh environments by sporulation, creating a thick cell wall to seal them off.
  27. Sex Pilus
    Long hollow protein tube that one bacterium makes and uses to transfer DNA to another bacterium (passes plasmids)
  28. Conjugation
    In prokaryotes, the direct transfer of DNA between two cells that are temporarily joined.
  29. Fimbriae
    Relatively shorter, solid protein rods used to adhere to surfaces (including your get wall)
  30. Flagella
    Protein whip attached to a motor- motility
  31. Lignins
    A hard material embedded in the cellulose matrix of vascular plant cell walls that provides structural support in terrestrial species
  32. Lamella
    Glues together primary and secondary walls in plants
  33. Tight junctions
    Are "water tight" protein seals formed between cells in skin, mucosa & gut epithelium
  34. Desmosomes
    Are made of intermediate filaments, a type of cytoskeleton; these are like rivets between the cells & they resist shearing forces that are prevalent in skin and muscle
  35. Intermediate filaments
    A component of the cytoskeleton that includes filaments intermediate in size between microtubules and microfilaments
  36. Nucleus
    Typically the largest organelle, made of the nuclear envelop, nucleolus and chromatin
  37. Nucleolus
    A specialized structure in the nucleus, consisting of chromosomal regions containing ribosomal RNA (rRNA) genes along with ribosomal proteins imported from the cytoplasm; site of rRNA synthesis and ribosomal subunit assembly.
  38. Chromatin
    The complex of DNA and proteins that makes up eukaryotic chromoses. When the cell is not dividing, chromatin exists in its dispersed form, as a mass of very long, thin fibers that are not visible with a light microscope.
  39. Ribosome
    A complex of rRNA and protein molecules that functions as a site of protein synthesis in the cytoplasm; consists of a large and a small subunit. In eukaryotic cells, each subunit is assembled in the nucleolus.
  40. rER
    site where phospholipid & protein destined for ER & other parts of the cell are made. Proteins are glycosylated in the rER
  41. Glycosylated
    The process in which a carbohydrate is joined to another molecule, such as a protein to form a glycoprotein or to a lipid to form a glycolipid. Glycosylation occurs in the rough endoplasmic reticulum and the Golgi aparatus of cells
  42. sER
    Has no ribosomes on the membrane surface, functions include steriod & other lipid synthesis, polysaccharide breakdown, and detoxification
  43. Golgi
    Finishes, sorts & ships molecules throughout the cells.
  44. Transport vesicles
    A small membranous sac in a eukaryotic cell's cytoplasm carrying molecules produced by the cell.
  45. Endo-membrane system
    The collection of membranes inside and surrounding a eukaryotic cell, related either through direct physical contact or by the tranfer of membranous vesciles; includes the plasma membrane, the nuclear envelope, the smooth and rough endoplasmic reticulum, the Golgi aparatus, lysosomes, vesicles and vacuoles.
  46. Peroxisome
    An organelle containing enzymes that transfer hydrogen atoms from various substrates to oxygen (O2), producing and then degrading hydrogen peroxide (H2O2).
  47. Glyoxysomes
    A typ of plant peroxisome, specialized for converting fatty acids to sugar for a source of energy.
  48. Summary of Organelle Function
    • Nucleus - where mRNA & Ribosomes are made
    • rER - phospholipids & protein synthesis
    • sER - other lipids made and site of some detoxification
    • golgi - protein modifications including
    • peroxisomes - breakdown of FA
    • storage - vacuoles, plastids
    • modification - rER - glyoproteins & gogli - modif. of glycoproteins
    • Detoxification - Peroxisomes & sER
    • Degradation - lysosomes
    • Transport - endomembrane vesicular transport system - rER & golgi
    • Energy conversion - mitochondira & choloplasts
  49. Cytoskeleton
    A structural framework for the cell and a means of movement of or within the cell
  50. Microtubules
    Are hollow tubes made of tubulin proteins, important in cell movement (flagella and cillia, chromosome movement (mitosis), veiscle and organelle movement (kinesin), and lay the track for primary cell wall cellulose needs to be laid down
  51. Microfilaments
    • Two intertwined strands of actin subunit polymers. They maintain cell shape (fine mesh - bear tension or pulling forces) and changes in cell shape (eg. pseudopodia formed during phagocytosis)
    • Microtubules resist compression while microfilaments resist stretching
    • In muscles myosin molecules 'grab onto & pull-on' actin filaments
    • Macrofilaments provide structure to microvilli
  52. Actin
    A globular protein that links into chains, two of which twist helically about each other, forming microfilaments (actin filaments) in muscle and other kinds of cells.
  53. Myosin motors
    • In muscles, myosin motors 'grab onto & pull-on' actin filaments
    • Also used to move fluids (pseudopodia, cytoplasmic streaming).
  54. Dynein
    pull on microtubules in flagella and cilia to move the organism
  55. Kinesin
    follow microtubules while moving vesicles/organelles
  56. Intermediate Filament
    • fibrous proteins supercoiled into 'cables'
    • Provide cell shape, anchorage of nucleus and some ther organelles, forms the nuclear lamina.
    • Provide an anchor for the microfilaments in intestinal microvilli
Card Set:
Biol 107
2012-04-26 14:26:35
Part One

Cell Organization
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