exam 1 practice key

8/18/2019 Exam 1 Practice Key

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Practice EXAM 1

Instructions1) Please do not open exam until told to do so.2) Before you begin, write your name and student ID on the Scantron sheet.

3) Count to be sure that there are pages, including this cover sheet.4

Exam begins on next page.

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For each group of statements below, select the answer from the right that bestcorresponds to the item on the left. For each group you may only use each answer once.

Group 1: Group 1 answers

02) A likely pH for a patient with extreme acidosis d) 703) the number of bonds in a ten carbon saturated fatty acid e) 9 04) The number of hydrogens in a hydrogen bond a) 1 05) The number of phosphates found in ATP b) 3

Group 2: Group 2 answers

06) Results in stable physiologic conditions e) homeostasis 07) Results in a metabolic pathway shifting which d) negative feedback

enzyme an intermediate binds08) Results in exceeding tolerance limits c) positive feedback 09) Results in a specific ion flowing down its gradient a) facilitated diffusion 10) Results in a specific ion flowing against its gradient b) 2° active transport

Group 3 Group 3 answers

11) Buffering d) pH regulation 12) Using ATP hydrolysis a) pumping

13) Result of dehydration synthesis e) proteins 14) Phospholipid heads b) polar 15) Ions found in water c) protons

Group 4 Group 4 answers

16) A characteristic of hydrophilic molecules a) hydrogen bonds 17) Flow of water across a membrane towards solutes e) osmosis 18) Devoid of polar bonds or charges d) hydrophobic 19) Can produce amino acids c) hydrolysis

20) Results from a failure of feedback b) hyperthyroidism

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21) In the figure above there is a membrane with 5 integral proteins. If the cell withthis membrane changes the fatty acids in this structure to increase their length, which ofthe proteins will be excluded from the membrane?

a) all of the proteins since changing their fatty acids affects them allb) Bc) A & Dd) A this is the only protein that depends on the width of the membrane e) none of the proteins will be affected, they do not have fatty acids

22) Can you state that there is water on both sides of this membrane in the figureabove?

a) no way to know.b) water is found only on the side with protein E.c) yes.

d) this is a hydrophobic structure, so no water is present

23) Which pH value is 100 times more basic than pH = 5?a) 7 b) 6 c.)4 d) 3

24) Ion channels are far more selective than hexose sugar carrier proteins. A goodexplanation for this is:

a. Ions are easier to distinguish from each other due to their relative charges.b. Hexose sugars are easily converted from one form to another.c. Ion channels use ATP to move ions down their gradient.d. Hexose sugars are difficult to distinguish since they all have six carbons.

25) Lipid rafts are regions in the membrane that have longer hydrocarbon chains. Theseserve to collect specific transmembrane proteins into a small area. The proteins do notbond with each other. What is the best explanation for how this ‘corralling’ happens?

a) The proteins form hydrogen bonds with the lipids’ hydrocarbon tails.b) The proteins have a hydrophobic region that is the same size as the lipid tails.c) The lipids exclude the proteins from the intracellular environment.d) The phospholipid ‘heads’ of the lipids are specific to these particular proteins.

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A

B

C

D

E



27) Carrier mediated transport, such as ____________, is used to move glucose _______ .a) facilitated diffusion – down a concentration gradientb).active transport – down a concentration gradientc) osmosis – up a concentration gradient

d) simple diffusion – up a concentration gradient

30) A consequence of negative feedback that regulates the first step in the process isthe accumulation of intermediates.

a) this is also a benefit since it will be easier to start the process again andimmediately have products.

b) this falsec) the is true, but the intermediates will cause problems as they build up.

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exam 1 practice key

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