BIOL 2100 Lecture Notes - Lecture 5: Peptide, Hydrogen Bond

1. The level of protein structure that is stabilized primarilyby non-covalent interactions between the side chains within asingle polypeptide chain is refered to as its:

A) primary structure

B) secondary structure

C) tertiary structure

D) quaternary structure

E) none of the above

2. Collagen, a strong fibrous protein found in connectivetissue, bone, and the extracellular matrix, has a structure inwhich three left-handed helices wind around each other to form aright-handed triple helix. The primary structure of collagen has arepeat unit of -(Gly-X-Pro)- Which of the following bonds stabilizethe collagen triple helix? (mark all that apply)

A) Hydrogen bonds between hydroxyproline residues

B) Hydrogen bonds between N-H and C=O

C) Ionic bonds between amino acid side chains

D) Hydrogen bonds between charged amino acids

3. The non-covalent forces that stabilize the Beta-strandconformation of peptides include:

A) H-bonds between amide C=O and amide NH

B) Van der Waals packing between the peptide backbone atoms

C) Van der Waals packing due to side chain interdigitation

D) Only A and B above

E) None of the above

4. What is the approximate length difference of a 22-kDasingle-stranded ?-helical protein segment vs. a 22-kDasingle-stranded ?-strand protein segment? Assume a mean residuemass of 110 Da. Show work.

5. Circular dichroism measurements have shown that the peptidebackbone of poly-l-lysine (KKKKKKK) adopts a random coilconformation at pH 7.0, but becomes ?-helical as the pH is raisedabove 10. This observation is known as the

Question 401 pts

Kinetic energy is the stored energy that can be used for motion.

Flag this Question

Question 411 pts

When an electron is transferred from one atom to another, and the two atoms are then electrically attracted to one another, a(n) ________________ bond is formed.

Flag this Question

Question 421 pts

Changing the number of ____________ of an atom would change the chemical properties of the atom.

Flag this Question

Question 431 pts

Forming molecules and breaking down molecules in biological organisms usually requires the use of _________ to help the reaction proceed faster.

Flag this Question

Question 441 pts

Organic molecules have a core composed of .

Flag this Question

Question 451 pts

The building blocks of carbohydrates are

Flag this Question

Question 461 pts

Water molecules crossing a membrane from high to low concentration is .

Flag this Question

Question 471 pts

Choose the membrane molecule responsible for the passage of polar molecules and ions into and out of the cell.

Flag this Question

Question 481 pts

The simplest cells are .

Flag this Question

Question 491 pts

Which of the following membrane bound organelles are found inside bacterial cells:

Flag this Question

Question 501 pts

Which of the following is a specialized components of the cell, is associated with the rough endoplasmic reticulum, and is responsible for making proteins.

Flag this Question

Question 511 pts

Proteins are sorted, modified, and packaged by the _____________ and later transported to the outside of the cell.

Flag this Question

Question 521 pts

Dehydration synthesis is a process of linking two smaller subunits together to form a polymer. Which of the following statements below is true of dehydration synthesis?

Flag this Question

Question 531 pts

Proteins are made up of _________ held together by peptide bonds.

Flag this Question

Question 541 pts

Which of the following gives an amino acid its properties?

Flag this Question

Question 551 pts

The final three-dimensional shape of a protein that includes the bonding of two or more polypeptide chains is call its _____ structure.

Flag this Question

Question 561 pts

How do DNA and RNA differ?

Flag this Question

Question 571 pts

Which of the following is a component of a DNA nucleotide?

Flag this Question

Question 581 pts

Cell membranes are made up of several different types of molecules. Select the membrane molecule below that is made up of a polar region and two non-polar fatty acid tails.

Flag this Question

Question 591 pts

Two organelles which are believed to have once been free-living bacterial cells are ____________ and ______________.

Flag this Question

Question 601 pts

The is an extensive system of internal membranes responsible for producing carbohydrates and lipids.