C. If the pH of a cytoplasmic compartment falls from 7.0 to 6.0 then:14) the gloves must fit15) the amount of H+ (hydronium) ions has increased16) the amount of -OH (hydroxide) ions has increased17) an acid with a pKa of 4.2 will lose its negative charge18) a base with a pKb of 6.8 will become positively charged19) phosphate functional groups will become positively charged

Name ____________________ BCOR 011 Vayda/Stratton Sept 14, 2005

PRACTICE EXAM QUESTIONS Lectures 1, 2 & 3 (Bonding & Functional Groups, Water, pH & Hydrophobicity, Carbohydrates, Lipids, Nucleic Acids &n Proteins, Cell Tour) NOTE: MEMBRANE STRUCTURE AND FUNCTION NOTE: MEMBRANE STRUCTURE AND FUNCTION WILLWILL BE ON THE EXAM BE ON THE EXAM

These are “dry-runs” for the Exams you will take. The questions here ARE exam questions from previous These are “dry-runs” for the Exams you will take. The questions here ARE exam questions from previous years (that’s why the jokes are so out of date). You will see questions similar to these on Sept 23 (with fresher years (that’s why the jokes are so out of date). You will see questions similar to these on Sept 23 (with fresher jokes).jokes).

Section I. MULTIPLE, Multiple Choice. Rarely is there just one right answer in life. These questions are designed to explore the different characteristics of individual things, processes or properties. Practice looking for ALL possible characteristics of an item while you are studying your notes.

-Indicate all of the answers below that correctly relate to the questions in bold type. Note: there is frequently more than one right answer! Sometimes there IS only one correct choice, other times none of the choices are correct, or all may be correct. Think of this as a type of “true-false” choice for each possible answer to the question. When you fill out the “bubble” answer sheet column 1 will be “true”, column 2 will be ”false”. On the the practice exambelow, you have 200 answer choices: so each choice is worth 0.5 pt; that is, if you say it is correct and it is, you get 0.5 pt; if you don’t say it is correct and it is, you lose 0.5 pt, etc. We the actual exam will probably be shorter (have less answer choices, like 150), so each choice will be worth more (like 0.67 pt). You only have 50 min for the 9/23 exam.

A. The structure at right:1) is a -sheet (beta)2) is a base pair3) is a micelle4) is a starch grain5) is an polysaccharide

 

B. The tertiary structure of a protein is: 6) the overall 3-D structure of the protein.7) dictated by interactions of amino acid R-groups with one another.8) dictated by interactions of the N-terminus with the C-terminus of the polypeptide.9) influenced by the presence of disulfide bonds.10) influenced by hydrophobic interactions.11) the interaction of two or more polypeptide chains to form a protein complex.12) the interaction of individual amino acids with one another to form a polypeptide.13) dictated by how the surfaces of secondary structures interact with one another.

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E. Covalent bonds:27) are formed when two atoms share electrons.28) enable atoms to form molecules with stable, precise spatial configurations29) give the molecule a positive charge at high pH 30) can be purchased through your stockbroker.

D. Which of the following biologically-important linkages are the result of condensation/dehydration reactions:

20) peptide bonds21) ester linkages22) phosphodiester bond23) James Bond24) hydrogen bonds25) Van der Waal’s interactions 26) Glycosidic bonds

G. Chiral carbons:36) are found in carbohydrate polymers37) are found in amino acids38) are found in polypeptides39) were found at Rockingham40) are found in saturated fatty acids41) are found in water42) are found in DNA43) have 4 different functional groups attached to them44) cannot interact with water

F. Atoms interact to attain chemical stability by:31) sharing electrons to form covalent bonds32) sharing the Oval Office33) “stealing” electrons to complete a stable outer electron shell34) forming micelles35) sharing intimate secrets with Linda Tripp

 

H. Amino acids:45) as monomers, can be expected to be ions at pH 7.046) with non-polar “R” groups include alanine, valine and leucine.47) can be joined in linear polymers to form polypeptides.48) were allegedly used by Nicole and Faye Resnick49) with alcohols for “R” groups include threonine and serine

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I. Intracellular membrane-bound organelles:50) Are typically observed in Prokaryotes51) Comprise distinct compartments within the cytoplasm52) Are the cell’s lock boxes53) Include “mitochondria” 54) are typically observed in Eukaryotes 55) include the “Golgi Apparatus”56) include the “endoplasmic reticulum”57) include “ribosomes”58) include “nuclei” (plural of “nucleus”)59) contain “phospholipids” in their membranes60) allow different functions to occur in a cell at the same time 61) allow different microcompartments within the cell to have distinct internal pH’s62) allow the cell to maximize effective surface area

K. A Carbon atom always makes this number of covalent bonds:71) one72) two 73) four74) eight

J. Water has a tendency to :63) Form hydrogen bonds with polar molecules64) Form hydrogen bonds with non-polar molecules65) Form four oxygen bonds with carbon molecules66) ionize and form the charged species –OH and H+

67) Form hydrogen bonds with hydrocarbon chains (R-CH2-CH2-CH2-CH3)68) Form hydrogen bonds with amino groups (R-NH2)69) Bomb Iraq70) Let the weapons inspectors do their job

L. Eukaryotic cells differ from prokaryotic cells in that eukaryotic cells:75) are typically much larger than prokaryotic cells76) contain internal membranes and membrane bound organelles whereas

prokaryotic cells typically do not77)) store their genetic information in the DNA whereas prokaryotic cells use RNA to

store genetic information 78) have nuclei whereas prokaryotic cells do not79) have viruses whereas prokaryotic cells do not

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M. Which of the following is a membrane-bound organelle?80) ribosome81) nucleus82) triglyceride83) microtubule

N. A covalent bond between a carbon and a hydrogen atom is considered:84) nonpolar85) polar86) ionic87) ironic 88) romantic

O. A solution with a pH of 5 :89) has a hydrogen ion concentration of 1x10-9M 90) has a water concentration of 5 M91) has a hydrogen ion concentration of 0.00001M92) cannot form hydrogen bonds

P. A carboxylic acid group with a pKa of 5.5:93) Will be ionized at pH 7.094) Will be uncharged at pH 7.095) Will be uncharged at pH 4.096) Will be uncharged at pH 8.897) Will bear a negative charge in a solution that has 1x10-10 M –OH ions98) Can form a condensation reaction with an alcohol group to form an ester bond99) Is hydrophilic

Q. Which of the following components are found in prokaryotes (bacteria and cyanobacteria)?100) plasma membrane102) nucleus103) endoplasmic reticulum 104) golgi apparatus105) ribosomes106) DNA107) bloody gloves108) mitochondria109) chloroplasts110) lysosomes111) Bruno Magli shoes

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R. Carbohydrate polymers are polar molecules which tend to:112) be insoluble in water.113) hydrogen bond with themselves rather than water.114) form micelles which are great for cleaning greasy dishes.115) be slimy, gooey or gelatinous when forced to be fully hydrated by water.116) serve as recognition markers on external surfaces of membrane proteins. 117) hydrolyze peptide bonds.

S. Which of the following components are usually found in DNA:118) phosphatidyl Choline119) Glutamic acid120) the preservative EDTA121) Adenosine monophosphate122) phosphatidyl Inositol123) Threonine124) deoxyRibose

U. Which of the following structures represents a monosaccharide?

131) C12H22O11 132)

133) HO – C = O | H – C – OH | H – C – OH | H

134)

T. Phospholipids tend to:125) form aromatic rings.126) be solids at room temperature if comprised of unsaturated fatty acids.127) form cholesterol.128) be hydrolyzed to cholesterol and wax.129) form bilayers and vesicles.130) bear a negative charge at pH 7.0.

V. An alpha helix ( -helix ) :135) Is a “primary structure” that a polypeptide can adopt 136) Is formed when one polar peptide bond hydrogen bonds with another peptide bond

further down the chain137) is held together by disulfide bonds138) Is the covalent bonding arrangement that holds two polypeptides into a quaternary

structure 139) Is a secondary structure of DNA and other polynucleotide chains

112113115116

121124

129130

132

136

1.    

W. Which of the following are considered “hydrophobic” amino acids with “hydrophobic” R groups140) glucose 144) serine 148) palmitic acid

  141) leucine 145) valine  142) phenylalanine 146) glutamine  143) adenine 147) lysine 

X. The molecule below :149) is the L form of an amino acid150) is likely to be a liquid oil 151) is a pentose152) is likely to bear a negative (-) charge at pH 7.0153) is a trisaccharide154) is comprised of one or more unsaturated fatty acids155) is hydrophobic156) was found on Monica Lewinski’s dress

Y. The SECONDARY STRUCTURE of DEOXYRIBONUCLEIC ACID (DNA) polymer:157) Is formed by linking ATP mononucleotides together158) Is a double-helix of anti-parallel strands159) Is an alpha () helix of two parallel strands160) Is a beta () helix of two anti-parallel strands161) Is stabilized by precise hydrogen bonding of complementary “bases” trapped in a

non-polar microenvironment; A with T, G with C162) Is driven by the need for hydrophobic bases to stack on top of one another163) Is driven by the insatiable desire for Bill Clinton to stack… (let’s not go there)164) Is driven by the political motives of Kenneth Starr

165) Has the negatively (-) charged phosphate groups on the outside, exposed to water 166) is maintained “fluid” by the presence of unsaturated fatty acids in the polymer

Among other things

Note: will never take off for a “joke” answer

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Z. The monomers which make up a polypeptide are:167) held together by phosphodiester bonds168) chiral169) nitrogenous bases170) unsaturated 171) nucleotides172) amino acids173) monosaccharides174) interns

AA. Cellulose and Amylose (starch):175) both contain the exact complement of amino acids but arranged in different orders176) are both polymers of D-glucose but monomers of one are bound together by 1-4

glycosidic linkages whereas the other is bound together by 1-4 glycosidic linkages

177) are both polysaccarides, but one is hydrophobic and the other is hydrophilic178) are polymers comprised of glucose but have very different 3-D shapes179) are amphipathic molecules180) are buffers which can bind ATP

BB. Which of the following amino acids has a hydrophilic R-group ? 181) isoleucine 182) threonine 183) arginine 184)

glutamic acid

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 CC. Familiarity with the properties of water is important to understand:185) Why polymers adopt the secondary and tertiary structures they do186) How soap works187) What chirality is188) What a “lock box” is189) Why we need a tax cut (didn’t Reagan try this already?)190) Why some hydronium (H+) ions and hydroxide (-OH) ions are always present for reactions in

water191) Why hydrophilic polymers tend to hydrogen bond with themselves rather than water192) Who this Chad guy is 193) How Chad got pregnant. 194) Why membranes form in water195) Why carbon atoms can form covalent bonds with 4 other atoms

DD. A molecule that is Chiral has :196) an unshared pair of electrons197) a pH of 7198) hydrophobic character199) a left-handed and right-handed form 200) at least one carbon with four different functional groups bonded to it

2. The fluid mosaic model of membranes predicts that:

a) O.J. did it.b) phospholipids are free to move laterally in membranes.c) proteins are free to move laterally in membranes.d) fluids are free to pass through membranes but solid particles cannot.e) polypeptides are embedded in a sea of phospholipids.f) polymers of D-glucose are soluble in water whereas polymers of -D-glucose are not.

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BCE