Ask Question, Ask an Expert


Ask Chemistry Expert

Multiple Choice problems based on the Primary, Secondary and Tertiary structures of Proteins.

1. In an α helix, the R groups on the amino acid residues:
a. Alternate between the outside and the inside of the helix.
b. Are found on the outside of the helix spiral.
c. Cause only right-handed helices to form.
d. Generate the hydrogen bonds that form the helix.
e. Stack within the interior of the helix.

2. A d-amino acid would interrupt a α helix made of l-amino acids. Another naturally occurring hindrance to the formation of an α helix is the presence of:
a. a negatively charged Arg residue.
b. a nonpolar residue near the carboxyl terminus.
c. a positively charged Lys residue.
d. a Pro residue.
e. two Ala residues side by side.

3. A sequence of amino acids in a certain protein is found to be -Ser-Gly-Pro-Gly-. The sequence is most probably part of a(n):
a. Antiparallel β sheet.
b. Parallel β sheet.
c. α helix.
d. α sheet.
e. β turn.

4. Which of the following statements is false?
a. Collagen is a protein in which the polypeptides are mainly in the α-helix conformation.
b. Disulfide linkages are important for keratin structure.
c. Gly residues are particularly abundant in collagen.
d. an α-keratin chain contains 7-residue pseudo-repeats of nonpolar/polar arrangements.
e. α-keratin is a protein in which the polypeptides are mainly in the α-helix conformation.

5. Determining the precise spacing of atoms within a large protein is possible through the use of:
a. Cryo-electron microscopy.
b. Light microscopy.
c. Small angle neutron scattering.
d. Ramachandran plots.
e. X-ray diffraction of protein crystals.

6. Experiments on denaturation and renaturation after the reduction and reoxidation of the -S-S- bonds in the enzyme ribonuclease (RNase) have shown that:
a. Folding of denatured RNase into the native, active conformation requires the input of energy in the form of hat.
b. Native ribonuclease does not have a unique secondary and tertiary structure.
c. The completely unfolded enzyme, with all -S-S- bonds broken, is still enzymatically active.
d. The enzyme, dissolved in water, is thermodynamically stable relative to the mixture of amino acids whose residues are contained in RNase.
e. The primary sequence of RNase is sufficient to determine its specific secondary and tertiary structure.

7. Diseases caused by protein misfolding include:
a. Mad cow disease.
b. Alzheimer's.
c. cancer.
d. all of the above.
e. a & b only.

8. A tandem mass spectrometer can sequence short peptides by:
1. hydrolysis of peptide bonds with a strong acid and identifying the amino acids by HPLC.
2. fragmenting the peptide and comparing the fragment masses.
3. determining the absorbance of the peptide at 280 nm.
4. measuring the molecular mass of the whole peptide.
5. the transfer of magnetization from one nuclei to another.

10. Which of the following pairs of bonds within a peptide backbone show free rotation around both bonds?
a. Cα-C and N-Cα
b. C=O and N-C
c. C=O and N-Cα
d. N-C and Cα-C
e. N-Cα and N-C

11. Which of the following statements concerning the process of spontaneous folding of proteins is false?
i. It may be an essentially random process.
ii. It may be defective in some human diseases.
iii. It may involve a gradually decreasing range of conformational species.
iv. It may involve initial formation of a highly compact state.
v. It may involve initial formation of local secondary structure.

Chemistry, Academics

  • Category:- Chemistry
  • Reference No.:- M919286

Have any Question? 

Related Questions in Chemistry

Assignmentyour task is to find the most suitable reactor

Assignment Your task is to find the most suitable reactor for the situation posed. NOTE: I will not accept chicken scratch on a piece of paper, nor will I accept anything photographed and emailed. Your assignment should ...

Answer these questions1 nbsp nbsp nbspat ph 92 seconal

Answer these questions: 1.      At pH 9.2, seconal absorbs at 239 nm. At pH 13, the absorbance shifts to 254 nm. Of what class of compounds is this characteristic and why? 2.      Three compounds were found to have the s ...

Position paper - chem 121 6380 chemistry in the modern

Position Paper - CHEM 121 6380 Chemistry in the Modern World (2168) Position Paper: To Frack or not to Frack Imagine you are the administrator of the city or town where you currently reside. A rich deposit of shale oil h ...

An unknown solid is entirely soluble in water on addition

An unknown solid is entirely soluble in water. On addition of dilute HCl, a precipitate forms. After the precipitate is filtered off, the pH is adjusted to about 1 and H2S is bubbled in; a precipitate again forms. After ...

Determining chemical formula of a hydratei need the pre lab

Determining Chemical Formula of a Hydrate I need the pre lab and post lab report as same as you did before. The original lab experiment details are attached in pdf. In prelab report, Must answer the Prelab Questions brie ...

Chemical bondingmcq questionsisostructural species are

CHEMICAL BONDING MCQ Questions Isostructural species are those which have the same shape and hybridization. Among the given species identify the isostructural pairs. [NF 3 and BF 3 ] [BF 4 - and NH 4 +] [BCl3 and BrCl 3 ...

1 according to estimates 10l of seawater contains on the

1. According to estimates, 1.0L of seawater contains on the average 4.0x10 -9 g of gold. If gold is worth $390 per troy ounce and a troy ounce weighs 31.103 g , how many cubic meters of seawater would have a million doll ...

A reaction will not occur when all the reactants and

A reaction will NOT occur when all the reactants and products in the ionic equation are spectator ions because no change occurs such as the formation of a precipitate or molecular compound. Which of the following combina ...

For the second-order reaction abproducts the rate of

For the second-order reaction A+B?Products, the rate of reaction r, may be written as r= dx/dt=k([A] 0 -X) ([B] 0 +X) X is the decrease in concentration of A or B as a result of the reaction. What are the condition for t ...

Safety considerationsbullthe temperatures of both the

Safety Considerations: • The temperatures of both the reboiler and the components inside are very hot and can cause burns so be cautious around the reboiler. Use proper gloves when collecting samples. • Ethanol can cause ...

  • 4,153,160 Questions Asked
  • 13,132 Experts
  • 2,558,936 Questions Answered

Ask Experts for help!!

Looking for Assignment Help?

Start excelling in your Courses, Get help with Assignment

Write us your full requirement for evaluation and you will receive response within 20 minutes turnaround time.

Ask Now Help with Problems, Get a Best Answer

A cola-dispensing machine is set to dispense 9 ounces of

A cola-dispensing machine is set to dispense 9 ounces of cola per cup, with a standard deviation of 1.0 ounce. The manuf

What is marketingbullwhat is marketing think back to your

What is Marketing? • "What is marketing"? Think back to your impressions before you started this class versus how you

Question -your client david smith runs a small it

QUESTION - Your client, David Smith runs a small IT consulting business specialising in computer software and techno

Inspection of a random sample of 22 aircraft showed that 15

Inspection of a random sample of 22 aircraft showed that 15 needed repairs to fix a wiring problem that might compromise

Effective hrmquestionhow can an effective hrm system help

Effective HRM Question How can an effective HRM system help facilitate the achievement of an organization's strate