Enzyme concentration increase in enzyme concentration

This preview shows page 11 - 14 out of 45 pages.

-Enzyme concentration: increase in enzyme concentration increases rate of reaction-Substrate concentration: increase in substrate concentration increases the rate ofreaction only up to the point of saturationoEnzyme saturationoccurs when so much substrate is present that all enzymemolecules are actively engaged in the chemical reaction, resulting in no further(notable) increase in reaction rate-Temperature: increase in temperature increases the reaction rate until the optimaltemperature is reached (104 degrees)oSevere decrease in reaction rate with temperature over 104 degrees-pH: function most efficiently at their optimal pHoBetween 6 and 8oIncrease in H+ results in additional H+ binding to the enzymeoDecrease in H+ results in the release of H+ from an enzymeoChange in H+ disrupts the electrostatic interactions and cause denaturationDifferent optimal pH in different parts of the body (stomach = 2-4)
-Competitive Inhibitors: interfere with the active site DIRECTLY-Non-competitive Inhibitors: allosteric inhibitors; change the shape of the enzyme so thesubstrate cannot bind to the active site4.Understand the concept of negative feedback (end-product inhibition) and how it affectsmetabolic pathways.
As product accumulates, it is more likely to become bound to the enzymeand inhibit the metabolic pathway, with progressively less and lessproduct being formedOver time, amount of product decreases, amount of allosteric inhibitorsbound to the enzyme decreases, and activity of that enzymatic pathwayincreases once againThis way, a steady state of product is producedChapter 4: Biology of the Cell1.Understand the differences between each of the following transport mechanisms:-Passive TransportoSimple diffusion: small, nonpolar molecules move into/out of a cell down theirconcentration gradientMoves from highsolute concentrationto low solute concentrationoOsmosis: passive movement of water through semipermeable membraneMoves from highwater concentrationto low water concentrationMolecules can cross plasma membrane in two ways:“Slip between” molecules of phospholipid bilayerOR move through protein water channels calledaquaporins-Channel-Mediated vs. Carrier-Mediated Transport (Facilitated Diffusion)oChannel-Mediated Transport: the movement of small ions across the plasmamembrane through water-filled protein channelsEach channel is typically specific for one type of ionThe channel is either a:leak channel, which (is continuously openorgated channel, is usually closed, opens only in response to astimulus, and then stays open for just a fraction of a second beforeit closes.

Upload your study docs or become a

Course Hero member to access this document

Upload your study docs or become a

Course Hero member to access this document

End of preview. Want to read all 45 pages?

Upload your study docs or become a

Course Hero member to access this document

Term
Fall
Professor
BROWN
Tags

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture