Biology ch 7 & 9

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Biology ch 7 & 9
2010-07-26 22:55:34
Biology cells diffusion osmosis cellular respiration

Biology chapters 7 & 9
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  1. cell theory
    • fundamental biological unit
    • smallest and simplest biological structure possessing all the characteristics of the living condition
    • all living orgaisms composed of one or more cells
    • every activity taking place in the living orgainism is ultimately related to metabolic activities in the cell
  2. Phospholipids
    •Major component of cell membranes-- make up the lipid bilayer.

    •Phosphate head attached to fatty acid tails.
  3. Proteins Embedded in Cell Membrane
    • •Serve as receptors
    • •Diffusion channels
    • •Facilitated diffusion channels
    • •Active transport channels
  4. Diffusion
    • the movement of molecules from high to low concentration
    • •Kool Aid moves from high concentration to low concentration
    • •Passive transport is diffusion across a membrane
    • Perfune disfuses through air
  5. Osmosis
    • •Movement of water across a membrane
    • •Water moves from where there is less solute to where there is more to
    • try to even it out
    • •Hypertonic has more solute
    • •Hypotonic has less solute
    • •Isotonic same amount of solute on both sides
  6. Hypertonic
    has more solute (greater osmolarity)
  7. Hypotonic
    has less solute (lower osmolarity)
  8. Isotonic
    same amount of solute on both sides (no net flow of water)
  9. Facilitated diffusion
    • diffusion with help of a protein
    • •Some molecules can’t get all the way through membrane
    • •Remember heads of phospholipids are charged but inside is not
    • •Few molecules can pass all the way through.
  10. Active Transport
    • •Uses ATP energy
    • •Moves a solute against its concentration gradient (to where more concentrated)
  11. Exocytosis
    • •Large molecules cannot pass through the membrane
    • •Vesicle moves to plasma membrane, fuses, and releases substance
    • •Hormones
    • •Endocytosis is opposite
  12. net flow
    flow of water from the hypotonic to the hypertonic solution
  13. plasmolysis

    plant cell in hypertonic solution - water moves out of the cell; the protoplast (cytoplasm enclosed by plasma membrane)shrinks and may pull away from cell wall - cell is described as plasmolyzed

    plant cell in isotonic solution - no net tendency for water to enter so cells become limp
  14. tugor pressure
    • pressure of the protoplasm on the cell wall due to the intake of water
    • plant cell in a hypotonic solution - water moves inside (into central vacuole) until protoplasm pushes on cell wall. Cell wall restricts expansion (tugor pressure) and begins to push water back out. Water enters and leaves the cell at the same rate.

    plant cell is stiff - plants prefer hypotinic solution
  15. osmolarity
    measure of solute concentration per liter or solute (number of solute particles disolved in the solution
  16. Is fresh water hypotonic, hypertonic, or isotonic to orgainc cells?
    Fresh water is hypotonic to living cells. Living cells are isotonic to seawater.
  17. molarity
    concentrate of solute in a solution
  18. Osmotically active substance
    solute that causes osmosis to occur - glucose outside a membrane that is not permiable to glucose - water will go through the membrane to dilute the glucose
  19. concentration gradient
    the concentration of somethings chances over a certain distance - dye in water diffused along the concentraion gradient from hightest concentraion to lowest until the whole class is equal
  20. water potential
    • the potential energy of water
    • Water potential quantifies the tendency of water to move from one area to another due to osmosis, gravity, mechanical pressure, or matrix effects such as surface tension.
  21. lysis
    lysis - blood cell in hypotonic solution - water rushed in and cell membranes burst

    crenate - blood cell in hypertonic solution - water leaves and cells shrivel
  22. Cellular Respiration
    • Respiration uses the oxygen and produces carbon dioxide.
    • C6H12O6(glucose)+ 6O2 → 6CO + 6H2O+ATP(energy)
    • Takes several steps -occur through the movement of electrons
    • Redox Reactions
    • Two hydrogen atoms are removed from glucose (oxidation) and transfered to a coenzyme called NAD+ which becomes NADH + H+
    • NADH transfers electrons to the electron transport chain.
    • On the chain the transfer of electrons from one molecule to another releases energy, which can be used to make ATP.
  23. Fermentation
    • anaerobic process - uses no oxygen
    • transfers the energy in glucose bonds to bonds in ATP
  24. Redox Reactions
    • oxidation-reduction reactions
    • Substances are oxidized that lose electrons

    • Substances are reduced that gain electrons.
    • In this example the carbon compound is oxidized
    • C4H2O → C4O + 2H
    • Where do these hydrogens go? They reduce NAD+
    • NAD+ + 2H → NADH + H+

  25. What is NAD+?
    NAD+ is an electron acceptor important to the process of cell respiration

    Derived from the vitamin niacin.

    • Niacin is an essential vitamin and must be gotten from the diet. Found in green
    • veggies, peanuts, potatoes,and meat.

    Deficiency results in pellagra
  26. ATP reaction
  27. The Details of Respiration
    3 Main Stages

    • –Glycolysis (cytoplasm)
    • –Krebs Cycle (mitochondria) - also called Citric Acid Cycle
    • –Electron Transport Chain (mitochondria) - also called Oxidative Phosphorylation
  28. Glycolysis
    • Breaks glucose into pyruvic acid (6 carbons to 3carbons)
    • Beginswith 1 molecule ends with 2
    • Series of 9 steps; enzymes needed; several intermediates
    • Produces 2 net ATP and 2 NADH
    • Universal
  29. Pyruvic Acid Prepares for Krebs Cycle
    • NAD+ goes to NADH
    • Carbon atom released as CO2
    • Pyruvic acid transformed to Acetyl CoA
    • Coenzyme A is derived from vitamin B
    • Coenzyme A is recycled after start of Krebs cycle
  30. At end of Krebs Cycle
    • 4 ATP
    • 10 NADH
    • 2 FADH2
    • On to electron transport chain to make more energy.
  31. Electron Transport Chains
    • NADH will give electron to electron carrier.
    • Electron carriers are proteins
    • Last step is oxygen.
    • ATP is produced as electrons fall toward oxygen.
    • Process allows cell to harvest energy as the electron falls (water wheel).
  32. So how is ATP made?
    • Remember ATP is made from ADP by phosphorylation
    • A special enzyme ATP snythase can use the energy created by the electron transport chain to add a phosphate to ADP
    • CreatesATP molecules
  33. So How Much ATP from 1 Glucose?
    • 4 ATP from glycolysis and Krebs cycle
    • Estimated 34 from electron transport
    • Total of 38 ATPs from 1 molecule of glucose– about 40% of energy present
  34. What if there is no oxygen? Can a cell survive?
    Yes, many organisms can survive just on glycolysis

    • Yeast produce alcohol and CO2 through fermentation (recycles NAD+)
    • Lactic acid fermentation can be done by muscle cells in strenuous exercise
  35. Is glucose the only material that can be used to make ATP?
    No, proteins and fats can also be used.

    And ATP can be used to make macromolecules needed for cell function
  36. Aerobes
    aerobe is an organism that can survive and grow in an oxygenated environment
  37. Anaerobes
    • anaerobe is any organism that does not require oxygen for
    • growth, could possibly react negatively and may even die in its
    • presence
  38. Facultative Anaerobe
    A facultative anaerobic organism is an organism, usually a bacterium, that makes ATP by aerobic respiration if oxygen is present but is also capable of switching to fermentation
  39. Coenzyme
    • A cofactor is a non-protein chemical compound that is bound to a protein
    • and is required for the protein's biological activity.
  40. ATP synthase
    ATP synthase is a general term for an enzyme that can synthesize adenosine triphosphate (ATP) from adenosine diphosphate (ADP) and inorganic phosphate by using a form of energy.
  41. Enzymes
    Enzymes are proteins that catalyze (i.e., increase the rates of) chemical reactions. In enzymatic reactions, the molecules at the beginning of the process are called substrates, and the enzyme converts them into different molecules, called the products. Almost all processes in a biological cell need enzymes to occur at significant rates
  42. Oxidation
    • Oxidation is the loss of electrons or an increase in oxidation state by a molecule, atom, or ion.
    • oxidation of carbon to yield carbon dioxide (CO2)
  43. Reduction
    Reduction is the gain of electrons or a decrease in oxidation state by a molecule, atom, or ion.
  44. Redox Reaction
    Redox (shorthand for reduction-oxidation reaction) describes all chemical reactions in which atoms have their oxidation number (oxidation state) changed
  45. Kinds of Passive Transport
    Diffusion - molecules move from high to low concentration

    Osmosis - water moves through membranes looking for isotonic

    Facilitated - protein used to move large molecule (sugars, amino acids, ions, water) - uses no energy

    Aquaporin - protein that ONLY water can use to move fast
  46. Active Transport
    • Uses Energy - against the concentration gradient
    • 1. Exocytosis - movement of molecule out of cell - secretions (insulin) - cells form vaccuole around it and pushes it out of cell
    • 2. Endocytosis - movement of molecules into the cell
    • a. Phagocytosis - eating - bringing food into cell
    • b. Pinocytosis - drinking - bring fluids into cell
    • c. Receptor-mediated - receptor proteins are embeded in the membrane that collect a specific substance.
  47. Cellular streming
    Amoebas move by streaming its body forward and pulling up behind
  48. How do lysosomes move through the cell?
    move across Intermediate filaments
  49. 3 Types of Endocytosis
    • 1. Phagocytosis - eating - bringing food into cell
    • 2. Pinocytosis - drinking - bring fluids into cell
    • 3. Receptor-mediated - receptor proteins are embeded in the membrane that collect a specific substance.
  50. Selective permeability
    • important function of membrane
    • allows some substances to cross more easily that others
  51. What two molecules can move easily through the plasma membrane?
    CO2O2 - oxygen
  52. Oxidative Phosphorylation
    • occurs in the membrane on the cristae of the mitochondria
    • Electron Transport Chain = (H+) gradient across the membrane (out)
    • +Chemiosmosis = ATP synthesis powered by the flow of H+ back across the membrane
  53. lactic acid fermentation
    • pyruvate is reduced (by NADH) to lactate (ionized form of lactic acid)
    • Gives off NO CO2