13 Jan This will be used for 30-34. (2 pts ea/1

NAME _________________________________________________________

Please be careful in your reading of all of the instructions and the questions. Please ask if you have any problems in understanding what is required for each question. Write yourname on the examand the scantron sheet.

Numbers 1 through 10 are either true (A) or false (B). Please place your answer on the scantron sheet. Mark clearly and erase completely. (1 point each/10 total//10 overall)

1.___ Dialysis is defined as a cell membrane experiencing diffusion of solute molecules moving primarily from a region of higher solute concentration to a region of lower solute concentration.

2.___Molecules that move directly through the phospholipid bilayer of the membrane most rapidly by means of simple diffusion are charged, highly polar and small in size.

3.___ During receptor mediated endocytosis the cell produces long pseudopods that can enclose whole bacterial cells and this produces small endocytotic vesicles that peroxisomes attach to once they are inside the cell.

4.___ A protein molecule that is responsible for moving sodium atoms out of the cell and potassium atoms into the cell, each against their concentration gradients, is an example of an active transport, antiport-carrier protein.

5.___ If electrogenic pumps are embedded in the cell membrane of a bacterial cell and are moving hydrogen ions from the cytoplasm to the extracellular region then you should conclude that the extracellular region has a higher pH and a more negative charge than the cytoplasm.

6.___The active transport of sodium ions from the cytoplasm of a eukaryotic cell to the extracellular space would be an example of an electrogenic pump creating a situation of unequal sodium distribution, an ion concentration gradient, a gradient of charge and stored potential energy.

7.___ Lysosomes may be involved in the digestion of cells and debris, taken in from the outside environment in contractile vacuoles, through the process of autophagy.

8.___ Proteins that are referred to as multi-pass proteins are integral transmembrane proteins with repeated alpha helical motifs passing through the cell membrane and they are produced by bound ribosomes associated with the rough ER.

9.___ Glycolipid anchored proteins are made exclusively by free ribosomes and are found exclusively attached to the intracellular surface of the plasma membrane.

10.___The pseudopod (filipod/lamellapod) extensions of cell membranes are formed internally by components of the cytoskeleton called microtubules and require keratin proteins to form.

Numbers 11 through 20 matching. Please make only one choice for each, no choice is used twice and some choices are not used at all. Please also note that some answers require you to fill in two letters on the answer sheet. For example choiceJ requires letter spacesB & C filled in.

(1 pt ea/ 10 tot//20 overall)

11.___ Carrier A. Organelle that is responsible collecting water from the cytoplasm of a protistan cell (Paramecium) and actively pumping water to the extracellular environment utilizing myosin motor proteins.

12.___ Coenzyme B. This term is utilized to identify the organic, non-protein cofactor molecules that form a permanent portion of an enzyme’s structure by binding to the apoenzyme.

13.___ Cilia C. The movements of ER/Golgi vesicles in the anterograde direction through the endomembranous system are dependent on the movement of these motor proteins in the microtubule + direction.

14.___ Clathrin D. This term is used to identify the membrane channel protein responsible for rapid diffusion of the cellular solvent molecule.

15.___Contractile Vacuole E. This is an example of an organic cofactor of an enzyme that binds temporarily to the protein portion of the enzyme, many are commonly called vitamins.

16.___ Pseudopods F(AB) Flexible cellular extension with internal microtubule protein 9+2 structure and has associated dynein motor proteins that can move (bend) the structure at a rate of 40-60 times /sec.

17.___Keratin G(AC) Formed by actin microfilaments during endocytosis when a macrophage of your immune system consumes a bacterial cell or large clusters of cellular debris.

18.___Kinesin H(AD)The protein triskelion material that is directly associated with coated vesicle formation and binding to receptor proteins.

19.___Myosin I(AE). These are the key type of motor proteins associated with cytokinesis in dividing cells, cytoplasmic streaming in plants and muscle contraction in animal cells.

20.___Prosthetic group JBC). Integral transmembrane protein that is required for the active transport of molecules across the membrane.

K(BD). These are the key motor proteins associated with the bending of the microtubules found making up the structure of flagella and cilia.

L (BE).These proteins are key components of the cytoskeleton of the epithelial cells of your body, and represent a prime example of intermediate filaments in those cells.

Numbers 21 through 29 are multiple choice. For each please mark theone best answer.

( 2pts ea/ 18 tot// 38 overall).

21.__ How would you describe the location involving the binding of a substrate to an enzyme?

A. It would also bind to a noncompetitive inhibitor by means of irreversible binding.

B. It would be able to bind to an allosteric activator by means of irreversible binding.

C. It would bind to any molecule that has the chemistry of a noncompetitive inhibitor.

D. It would be the portion of the enzyme to be involved in catalyzing a chemical reaction

E. It would be the site where a coenzyme would bind after the completion of catalysis.

22.__ Which of the following would be categorized as: Amolecule whosestructure would allow binding to the same location as the normal substrate, is classified as a type of venom molecule with a conformation similar to the normal substrate, and result in permanent dysfunction (inhibition) of the enzyme.

A. noncompetitive reversible inhibitor

B. allosteric regulatory inhibititor

C. competitive irreversible inhibitor

D. irreversible allosteric inhibitor

E. competitive reversible activator

23.___ If an allosteric enzyme is located in a cellular metabolic pathway that is regulated by feedback inhibition then which of the following would you expect to be true of that feedback system.

A. The molecule that is the allosteric inhibitor should be the final product of the metabolic pathway.

B. The molecular product of the first enzyme would be the inhibitor of the metabolic pathway.

C. The catalytic subunit of the allosteric enzyme would bind to a competitive inhibitor.

D. The regulatory subunit of the allosteric enzyme would be bound to a noncompetitive inhibitory molecule.

E. The regulatory enzyme would be at the final position, the last reaction, of the metabolic pathway.

24.___ Which of the followingis not a true characterization of enzymes or enzyme function.

A. Enzymes are composed primarily of proteins but may also have inorganic and organic cofactors attached.

B. Enzymes lower the activation energy required by a chemical reaction.

C. Enzymes can be altered in function and/or form by high temperature or extremes of pH.

D. Enzymes can be used over and over because they are not altered as a result of the involvement in a chemical reaction.

E. Enzymes are never changed in shape during their activities as they catalyze chemical reactions.

25.___ Which of the following is an incorrect representation of membrane structure.

A. Membranes are described as being a fluid mosaic with both a highly flexible nature and a composition including lipids, proteins, and carbohydrates.

B. The phospholipid bilayer of the membrane has both a hydrophobic interior and both external surfaces are hydrophilic.

C. The two leaflets of the bilayer are typically very similar in terms of the variety of phospholipids present, with very little difference in composition.

D. Glycolipid anchored proteins are located on the exterior surface of the membrane and lipid anchored proteins are on the interior surface.

E. Integral and integral transmembrane proteins of the membrane all have an amphipathic nature.

26.____ Which of the following is acorrect statement concerning the process of osmosis associated with a selectively permeable membrane. Consider our model system discussed in class.

A. Water cannot diffuse from a hypertonic solution to a hypotonic solution.

B. Cells placed in isotonic solutions have no solute diffusing through their cell membrane therefore the cell looks the same as before, no change in appearance.

C. Animal cells that are placed in a hypertonic solution typically swell to the point of lysis (cytolysis), due to gain of water.

D. Water will primarily flow (diffuse) through a membrane from a hypotonic solution into a hypertonic solution.

E. The greater the solute concentration differences between two solutions the slower the rate of osmosis that will occur between those two solutions.

27.__ Which of the followingis an incorrect conclusion (prediction) concerning cells and the adaptations associated with S/V. Cells are :

A. small and/or spherical to reduce S/V ratio.

B. large and/or spherical to maximize S/V ratio.

C. large and/or irregular to reduce S/V ratio.

D. small and/or irregular to maximize S/V ratio.

E. small with increased internal membranes to minimize S/V.

28.__ Which of the followingis not correctconcerning elements of the cytoskeleton and motor proteins.

A. Dynein motor proteins are associated with microtubules and have the capacity to move vesicles toward the negative end of the microtubule.

B. Vesicles that are moved between the ER and Golgi are “carried or pulled” along microtubules by motor proteins.

C. The processes of cyclosis (cytoplasmic streaming) and contractile vacuole function are both associated with the interactions of myosin motor proteins with microfilaments.

D. The key events associated with skeletal muscle contraction are interactions between keratin intermediate filaments and kinesin proteins.

E. Microfilaments are associated with the internal support and structure of the cell processes called microvilli and pseudopods.

29.__ Which of the followingis not correct concerningthe formation of protein coated vesicles.

A. The coating proteins attach to membrane peripheral protein receptors but only after the membrane has formed itself into a vesicle.

B. Protein coated vesicles are associated with both the anterograde and retrograde movement of vesicles between components of the endomembranous system.

C. Clathrin proteins may be associated either with receptor mediated endocytosis or the formation of lysosomal vesicles.

D. Coating proteins must be able to attach to receptor proteins external Golgi domains (cytoplasmic domain) but only after a mannose 6 phosphate protein is attach to the luminal Golgi domain of the receptor protein.

E. Protein coated vesicles may attach to motor proteins like kinesins or dyneins, and are moved by these motor proteins to their target membranes for fusion.

.gif”>.gif”>.gif”>.gif”>.gif”>.gif”>.gif”>.gif”>.gif”>.gif”>.gif”>.gif”>Please use the following space to correctly complete the following illustration.

This will be used for 30-34. (2 pts ea/10 tot // 48 overall)

You have a cell of 20% solute concentration. Assume a simple solution of only 1 solute and 1 solvent molecule.In each of the three cases (A,B,C) in the lower part of the illustration the arrows are for thedialysis occurring between the cellular (intracellular) solution and the extracellular solution. The solvent molecule is also able to freely diffus