BCH 400 Exam 1 Practice

Centrifugation for DNA Replication a. 1000 xg for 10 min pellet b. 10,000 xg for 10 min pellet (Mito) c. 105,000 xg for 90 min pellet (ER) d. 105,000 xg for 90 min supernatant

1,000 xg for 10 min pellet

sulfur containing a.a.

cys

separates proteins on the basis of size

gel filtration chromatography

In the central dogma of biology, only one of the processes involves a change in language. It is the process of a. replication b. translation c. transcription d. reverse transcription

translation

Detergents a. Hydrophobic Interactions b. Increases vibrational and rotational energy in proteins c. Break disulfide bonds d. Hydrogen Bonds e. Ionic Bonds

Hydrophobic Interactions

Function of Golgi Complexes?

Package Proteins

Which of the following amino acids has a hydrophobic side chain? a. lys b. phe c. glu d. ser

Phe

Which of the following amino acids have more than one chiral center? a. Thr & Ile b. Ala c. Phe d. Gly

Thr & Ile

chromatin sub-cellular location

nucleus

After adding sulfur to his garden to lower the pH after years of adding sodium and potassium hydroxide from fireplace ash, Blomquist's garden pH was 5.0. The concentration of -OH ions is a.) 1*10^-5 b.) 1*10^-7 c.) 1*10^-9 d.) 1*10^-14

1*10^-9

which of the following cell fraction would you find the proteins involved in oxidative phosphorylation? a. 10,000 xg for 10 min pellet b. 105,000 xg for 90 min pellet c. 105,000 xg supernatant d. none of the above

10,000 xg for 10 min pellet

Centrifugation for ATP Synthesis a. 1000 xg for 10 min pellet b. 10,000 xg for 10 min pellet (Mito) c. 105,000 xg for 90 min pellet (ER) d. 105,000 xg for 90 min supernatant

10,000 xg for 10 min pellet (Mito)

drug metabolism, complex lipid synthesis and protein synthesis are all found in the same sub cellular fraction of a cell. What fraction are they found in?

105,000 xg for 90 min pellet

Centrifugation for Hexokinase (a glycolytic enzyme) a. 1000 xg for 10 min pellet b. 10,000 xg for 10 min pellet (Mito) c. 105,000 xg for 90 min pellet (ER) d. 105,000 xg for 90 min supernatant

105,000 xg for 90 min supernatant

Centrifugation for Protein Synthesis a. 1000 xg for 10 min pellet b. 10,000 xg for 10 min pellet (Mito) c. 105,000 xg for 90 min pellet (ER) d. 105,000 xg for 90 min supernatant

105,000 xg for pellet (ER)

Xenobiotic Metabolism a. 1000 xg for 10 min pellet b. 10,000 xg for 10 min pellet (Mito) c. 105,000 xg for 90 min pellet (ER) d. 105,000 xg for 90 min supernatant

105,000 xg for pellet (ER)

If an aqueous solution is at pH of 5.0, what is [OH-]? a. 10^-5 b. 10^-7 c. 10^-9 d. none of the values on the left

10^-9

the pKa values for glutamic acid 2.1, 4.1 and 9.5. What is the pI for glutamic acid?

3.8

After adding too much ash from his fireplace to his garden, blomquist added sulfer and allowed the [OH-] to go to 1 x 10^-10 M. What is the pH at this hydroxyl ion concentraton?

4.0

The pKa values for glutamic acid are 2.1, 4.1, and 9.5. WHat is the pI for glutamic acid? a. 6.8 b. 3.1 c. 7.85 d. 2.1 e. 4.1

6.8

Function of Mitochondria?

ATP Production

The pKa of the imidazole side chain on histidine is 6.0. Would a buffer of histidine at pH=6.5 buffer best against added acid or added base? a. acid b. base c. equally well for both

Acid

A buffer consisting of histidine (pKAs 3.9,6.0,9.7) at 5.5 would buffer best against a. Added base b. Added acid c. Equally well against both

Added Base

Which of the following amino acids has the lowest molecular weight? a. ala b. leu c. glu d. cys

Ala

Which group of amino acids would you most likely find associated with a membrane spanning protein? a. glu, asp, lys, arg b. tyr, ser, thr c. ala, phe, val, ile d. gly,cys, his

Ala, Phe, Val, Ile

The peptide ala-phe-leu-met-ser-pro was subjected to one round of Edmand degradation. Which amino acid would be cleaved from the peptide and analyzed as a PTH derivative? a. Pro b.Ala c. Phe d. Leu e. Met

Alanine

In sickle cell anemia, a Glu on position 6 of the beta chain is replaced by a Val, and the change can be deleterious. Which of the following amino acid changes in a protein is least likely to result in a change in the function of a protein? a. phe for a tyr b. arg for a lys c. ile for glu d. cys for met

Arg for a Lys

Mercaptoethanol a. Hydrophobic Interactions b. Increases vibrational and rotational energy in proteins c. Break disulfide bonds d. Hydrogen Bonds e. Ionic Bonds

Breaks Disulfide Bonds

Which of the following bonds is the most non-polar? a. C-H b. C-C c. C-O d. C-N

C-C

which of the following bonds is most polar? a. C-C b. C-H c. C-O d. C-N

C-O

Which of the following is in the most oxidized state? a. Carbon dioxide (CO2) b. Formic Acid (H-CO2H) c. Methanol (CH3OH) d. Methane (CH4)

Carbon Dioxide (CO2)

What is the charge on the dipeptide Aspartame (asp-phe-methyl ester) at the pH of coca cola (2.53), assuming the pKa of the asp side chain carboxyl group is 3.53? a. Close to +1 b. Close to 0 c. Close to -1

Close to 0

Which of the following types of bonds is not used to stabilize quaternary structure? a. Covalent Bonds b. Hydrophobic Bonds c. Interaction of apolar side chains

Covalent Bonds

Type of Bonds in Primary Structure a. hydrophobic interaction, no cavelent bonds b. disulfide, H-Binds, hydrophobic, ionic, prosthetic group interactions c. Hydrogen bonds play a major role d. Covalent peptide bonds

Covalent Peptide Bonds

Type of Bonds in Tertiary Structure a. hydrophobic interaction, no cavelent bonds b. disulfide, H-Binds, hydrophobic, ionic, prosthetic group interactions c. Hydrogen bonds play a major role d. Covalent peptide bonds

Disulfide, H-Bonds, Hydrophobic, ionic, Prosthetic Group Interactions

Which of the following is correct in order of size? a. Euk cell>prok cell> hemoglobin> ribosome b. Hemoglobin>Myoglobin>Glucose c.Hemoglobin>Myoglobin>Ribosome>Glucose d. Mitochondria>Ribosome>Prok cell>Glucose

Hemoglobin>Myoglobin>Glucose

Function of Lysosome?

High in Proteolytic Enzymes

Which of the following elements has the lowest electronegativity? a. H b. N c. O d. F

Hydrogen

Urea a. Hydrophobic Interactions b. Increases vibrational and rotational energy in proteins c. Break disulfide bonds d. Hydrogen Bonds e. Ionic Bonds

Hydrogen Bonds

Type of Bonds in Secondary Structure a. hydrophobic interaction, no cavelent bonds b. disulfide, H-Binds, hydrophobic, ionic, prosthetic group interactions c. Hydrogen bonds play a major role d. Covalent peptide bonds

Hydrogen bonds

Type of Bonds in Quaternary Structure a. hydrophobic interaction, no cavelent bonds b. disulfide, H-Binds, hydrophobic, ionic, prosthetic group interactions c. Hydrogen bonds play a major role d. Covalent peptide bonds

Hydrophobic Interaction, no covalent bonds

Leu a.) Hydroxyl Containing a.a. b.) Sufur containing a.a. c.) Hydrophobic a.a. d.) side chain has a carboxylic acid e.) side chain has a positive charge ay pH=7.0

Hydrophobic a.a.

Ser a.) Hydroxyl Containing a.a. b.) Sufur containing a.a. c.) Hydrophobic a.a. d.) side chain has a carboxylic acid e.) side chain has a positive charge ay pH=7.0

Hydroxyl containing a.a.

Low or High pH a. Hydrophobic Interactions b. Increases vibrational and rotational energy in proteins c. Break disulfide bonds d. Hydrogen Bonds e. Ionic Bonds

Ionic Bonds

Which statement does not pertain to a peptide bond? a. It is an amide b. It is rigid and planar c. It is between amino acids in a protein d. It connects the side chains of acidic and basic amino acids

It connects the side chains of acidic and basic amino acids

Which of the following amino acids would be positively charged at pH=7.0? a. lys b. glu c. val d. none of the above

Lys

Which of the following chemicals/techniques to denature proteins deals primarily with breaking disulfide bonds? a. mercaptoethanol b. urea c. SDS d. high temperature

Mercaptoethanol

Which of the following is a commonly used reagent to reduce disulfide bridges? a. Ethanol b. Sulfuric Acid c. Mercaptoethanol d. Hydrogen Peroxide

Mercaptoethanol

Which of the following amino acid changes in a protein would least likely lead to a change in the function of the protein? a. val for lys b. met for ile c. asp for lys d. his for cys

Met for Ile

Which of the following subcellular organelles is about the same size as a bacterium? a. Nucleus b. Golgi Apparatus c. Mitochondria d. Ribosome

Mitochondria

Which of the techniques listed below could be used to estimate the size of a protein? a. affinity chromatography b. gel permeatation chromatography c. SDS-PAGE d. more than one of the above

More than one of the above

The side chain of which of the following amino acids will not participate in hydrogen bonds? a. ser b. phe c. tyr d. glu

Phe

Which of the following group of amino acids are most abundant in collagen? a. ile, val, leu b. pro, gly c. glu, asp d. his, lys, arg

Pro, Gly

Function of Rough Endoplasmic Reticulum?

Protein Synthesis

Which of the following is a Bronsted Base? a. R-NH3+ b. R-CO2- c. R-CO2H d.none of the above

R-CO2-

Which of the following is a Bronstad acid? a. R-NH3+ b. R-CO2- c. R-NH2 d. none of the above

R-NH3+

The shape of hair is determined in part by the pattern of disulfide bonds. Which of the following procedures could be used to break disulfide bonds in hair proteins? a. Oxidation of disulfide bonds b. Reduction of disulfide bonds with mercaptoethanol c. Use of SDS to denature protein d. Adding oil to change hydrophobic bonds

Reduction of disulfide bonds with mercaptoethanol

Glu a.) Hydroxyl Containing a.a. b.) Sufur containing a.a. c.) Hydrophobic a.a. d.) side chain has a carboxylic acid e.) side chain has a positive charge ay pH=7.0

Side chain has a carboxylic acid group

Lys a.) Hydroxyl Containing a.a. b.) Sufur containing a.a. c.) Hydrophobic a.a. d.) side chain has a carboxylic acid e.) side chain has a positive charge ay pH=7.0

Side chain has a positive charge at pH=7.0

Which of the following techniques separate proteins of the basis of size? a. Size exclusion chromatography and SDS-PAGE b. Ion Exchange Chromatogrphy c. Affinity Chromatography d. NMR

Size Exclusion Chromatography and SDS-PAGE

Cys a.) Hydroxyl Containing a.a. b.) Sufur containing a.a. c.) Hydrophobic a.a. d.) side chain has a carboxylic acid e.) side chain has a positive charge ay pH=7.0

Sulfur containing a.a.

Which of the following statements about peptide bonds is not true? a. The four atoms in a peptide bond and the attached alpha-carbons are in a plane b. The hydrogen on the nitrogen and the carbonyl carbon are trans c. The R groups on adjacent amino acid residues are cis d. In the peptide bond, the bond between the carbonyl carbon and the nitrogen has partial double bond character

The R groups on adjacent amino acid residues are cis

Function of Smooth Endoplasmic Reticulum?

Xenobiotic Metabolism

you are using cys (pKa of side chain = 8.3) to buffer a solution at pH = 7.5. Would cys buffer best against: a. added base b. added acid c. same against acid and base

added acid

based on the attraction to a specific chemical group or molecule

affinity chromatography

Which of the following a.a, has the lowest molecular weight? a. ala b. leu c. glu d. cys

ala

Diseases can be caused by improper folding of proteins. In a sense, we can think of prions as a. Chaperone porteins b. A good reason not to be a cannibal c. Proteins that induce beta-sheets and this protein aggregates d. All of the above

all of the above

Which of the following groups of amino acids all have a polar but non-ionizable side chain (at pH 1-14). a. glu, asp, lys b. asn, gln, ser c. ala, phe, ile d. thr, leu, met

asn, gln, ser

a means of identifying a protein

assay

Which is in the correct order according to size? a. glucose<ribosome<hemoglobin<bacterium b. bacterium>ribosome>hemoglobin>glucose c. ribosome<hemoglobin<baterium<red blood cell d. none of the above

b. bacterium>ribosome>hemoglobin>glucose

Which of the following have three amino acids have ionizable side chains? a.) Ser, Thr, Tyr b.) Glu, Asp, His c.) Ala, Leu, Val d.) Phe, Tyr, Trp

b.) Glu, Asp, His

Which is the correct order according to size? a. glucose<ribosome<hemoglobin<bacterium b. bacterium>ribosome>hemoglobin>glucose c. ribosome<hemoglobin<bacterium<red blood cell d. none of the above

bacterium>ribosome>hemoglobin>glucose

Which of the following does not occur in the nucleus of eukaryotic cells? a.) Replication b.) Transcription c.) Translation

c.) Translation

The heme prosthetic group... a. is the reason for cooperatively in the binding of oxygen to hemoglobin b. consists of a protophoryn and an iron c. is present only in myoglobin d. is the reason why myoglobin can bind oxygen molecules

consists of a protophoryn ring and an iron

glycolysis sub-cellular location

cytoplasm

Which of the following organelles is surrounded by two membranes? a.) Nucleus b.) Mitochondria c.) Chloroplast d.) All of the above

d.) All of the Above

Denaturing and renaturing a protein... a. requires heat b. requires breaking and reforming disulfide c. demonstrates that the primary structure of a protein determines the tertiary structure

demonstrates that the primary structure of a protein determines the tertiary structure.

side chain has a carboxylic acid group

glu

Which of the following types of interactions is primarily responsible for the secondary structure of proteins? a. hydrophobic bonds b. disulfide c. ionic bonds d. hydrogen bonds

hydrogen bonds

Heat a. Hydrophobic Interactions b. Increases vibrational and rotational energy in proteins c. Break disulfide bonds d. Hydrogen Bonds e. Ionic Bonds

increases vibrational and rotational energy in proteins

separates proteins on the basis of net charge

ion exchange chromatography

Which of the following statements about edman automated protein sequencing is not true? a. it sequences from the N-terminal end b. it sequences from the C-terminal end c. it requires high efficiency at each chemical step d. one can get up to 40 or 50 amino acids in a protein in a single automated run

it sequences from the C-terminal end

hydrophobic a.a.

leu

Which of the following a.a. would be + charged at pH=7.0? a. glu b. lys c. val d. none of the above

lys

side chain has a + charge at pH=7.0

lys

xenobiotic metabolism sub-cellular location

microsomes

ATP formation sub-cellular location

mitochondria

Which of the following amino acid substitutions in a protein would most likely lead to a change in the function of the protein. a. val for leu b. met for ile c. phe for lys d. glu for asp

phe for lys

What level of protein structure is primarily defined by alpha helices and beta sheets.

secondary

Which of the following chemicals/techniques to denature proteins deals primarily with breaking disulfide bonds? a. lys b. ser c. ala d. his

ser

hydroxyl containing a.a.

ser