- Hypertonic solutions cause __ (shrinking of cell due to osmosis). The central vacuole loses water, cell m membrane shrinks and pulls away from cell wall. When plant cells are placed in hypotonic solution admit water. As water enters. pressure builds up inside the cell __ pressure).When __ ). hydrostatic pressure =osmotic pressure the plant is said to have developed CARRIER MEDIATED TRANSPORT utilizes __ in cell membrane to control passage of molecules in and out of cell. 1) are __ - each carrier passes only one type molecule REQUIRES __ - is like diffusion in this sense molecules only pass along concentration gradient. how lipid-insoluble molecules like GLUCOSE and AMINO ACIDS cross the cell membrane.
- In cellular systems, water can move easily across membranes, but other molecules __ Therefore, it is often only water that can move and follow the law of diffusion. According to the law of diffusion, water will move from where it is more concentrated (less __ ) to an area of lower water concentration. The amount of solute per unit volume is referred to as __ With respect to cell systems ISOTONIC: HYPOTONIC: HYPERTONIC:
- diffusion is a __ process. All substances diffuse and no ener input ( __ ) Is required for diffusion to occur.
- to an area of Law of Diffusion: particles move from an area of __ until __ - diffusion is a __ process. The rate of diffusion is affected by the __ (the difference in concentration of the diffusing molecules between the two regions), the __ of the molecules, and the __ Diffusion in liquid is slower than in gas However, distribution of molecules in cytoplasm is speeded up by an ever-constant flow of the cytoplasm that is called cytoplasmic streaming Three Ways of increasing the rate of diffusion: 1. increase the __ 2. increase the __ 3. __ the size of the diffusing molecules The properties of the cell membrane allow few types of molecules to pass by diffusion: __ -soluble molecules like __ and __ can diffuse directly across because the membrane itself is made of
- 7. You are studying the effects of a new drug on the activity of your favorite enzyme The results of your assays indicate that the drug acts as a noncompetitive inhibito r. Which of the following changes to the Kim and Vmax allowe that deter mination to be made regarding the drugs actions? A. Km decreased Vmax increased B.Km unchanged Vmax decreased C.Km increased Vmax decreased D.Km decreased Vmax unchanged 8. Drugs that inhibit enzymes in an uncompetitive manner will have which of the following effects on the Michaelis Menten equation-deri ved parameters:Vmax and/or Km? A decrease both Vmax and Km B decrease Km but no effect on Vmax C. decrease Vmax but no change on Km D increase Km but no change in Vmax 9. Which of the following relates to allosteric enzymes? A. they are inactive on their substrates in the absence of accessory proteins B. they possess binding sites for regulatory molecules in addition to substrate binding sites C. they can convert multiple different substrates to product D. they can bind more than one substrate simultaneously 10. You are studying the effects of the addition of a potential pharmaceutical compound on the activity of your enzy me of interest You find that the addition of the c ompound results in an increase in the Km of th e reaction but does not affect the Vmax.Which of the following defines the inhibitory action of the compound? A competitive B .noncompetitive C. suicide D.uncompetitive 11 Enzymes are efficient catalysts because they can do which of the following? A. catalyze reactions that otherwise would not occur B decrease the free energy of activation of reactants C. prevent the conversion of product to substrate D. shift the equilibrium of reactions toward more complete conversion to product 12. Which of the following statements about allosteric enzymes is correct? A Allosteric enzymes display Michaelis -Menten kinetics. B .Allosteric enzymes are usually single subunit enzymes. C. Allosteric enzymes display hyperbolic curve D Allosteric enzymes control metabolism.
