Chapter 9, Proteins II: Structure-Function Relationships in Protein Families Video Solutions, Textbook of Biochemistry: With Clinical Correlations

Problem 1

Haptens
A. can function as antigens.
B. strongly bind to antibodies specific for them.
C. may be macromolecules.
D. never act as antigenic determinants.
E. can directly clicit the production of specific antibodies.

Joanna Quigley

Numerade Educator

01:01

Problem 2

In the three-dimensional structure of immunoglobulins,
A. $\beta$ -sheets align edge to edge.
B. in cach chain (H and L) the Cand V regions fold onto one another, forming CV associations.
$\mathrm{C}, \mathrm{C}_{\mathrm{L}}-\mathrm{V}_{\mathrm{L}}$ associations form the complementary sites for binding antigens.
D. free-SH groups are preserved to function in forming tight covalent bonds to antigens.
E. hinge domains connect globular domains.

Narayan Hari

Numerade Educator

01:03

Problem 3

In immunoglobulins all of the following are true except
A. there are four polypeptide chains.
B. there are two copies of each type of chain.
C. all chains are linked by disulfide bonds.
D. carbohydrate is covalently bound to the protein.
E. immunoglobulin class is determined by the $\mathrm{C}_{\mathrm{L}}$ regions.

Aditya Sood

Numerade Educator

03:29

Problem 4

Hemoglobin and myoglobin both have, are, can, or do all of the following except
A. subunits that provide hydrogen bonds to and nonpolar interaction with other subunits.
B. highly $\alpha$ helical.
C. bind one molecule of heme per globin chain.
D. bind heme in a hydrophobic pocket.
E. bind one $\mathrm{O}_{2}$ per heme.

Kyle Ukes

Numerade Educator

01:19

Problem 5

Isohydric transport of carbon dioxide from tissues to lung refers to
A. free $\mathrm{CO}_{2}$ dissolved in plasma.
B. $\mathrm{HCO}_{3}^{-}$ in plasma.
C. carbamino compounds.
D. the Bohr effect.
E. the presence of carbonic anhydrase in plasma.

Leah Lampen

Numerade Educator

02:09

Problem 6

Myoglobin has a Hill coefficient of 1.0 and hemoglobin has a Hill coefficient of $2.8 .$ This indicates that
A. an oxygen saturation curve for myoglobin would be sigmoidal.
B. hemoglobin exhibits a simple equilibrium binding of oxygen.
C. myoglobin shows negative cooperativity in its binding of oxygen.
D. hemoglobin shows positive cooperativity in its binding of oxygen.
E. only myoglobin would yicld a straight line in a Hill plot.

Alexander Cheng

Numerade Educator

01:30

Problem 7

Basal lamina structure is produced by connecting planar networks of laminins and type IV collagen.Which of the following statements about these is/are correct?
A. Both laminin and type IV collagen are composed of three polypeptide chains.
B. Laminin has a cruciform structure.
C. Laminin and type $\mathrm{IV}$ collagen are interconnected by a heparin sulfate proteoglycan.
D. Type IV collagen contains repeating sequences of (Gly-HyPro-Y)
E. All of the above.

Anas Venkitta

Numerade Educator

01:17

Problem 8

In addition to serine, the other two essential residues at the catalytic site of the serine proteases are
A. proline and hydroxyproline.
B. histidine and aspartate.
C. proximal and distal histidines.
D. the C-rerminal and N-terminal amino acids.
E. aspartate and glutamate.

Anitha Mary

Numerade Educator

02:34

Problem 9

Serine proteases
A. hydrolyze peptide bonds involving the carboxyl groups of serine residues.
B. are characterized by having several active sites per molecule, each containing a serine residue.
C. are inactivated by reacting with one molecule of diisopropylfluorophosphate per molecule of protein.
D. are exopeptidases.
E. recognize only the amino acids that contribute to the bond to be broken.

Bryan Lynn

Numerade Educator

00:43

Problem 10

All of the following are characteristic of serine proteases as a class
except
A. only one serine residue is catalytically active.
B. natural protein substrates and inhibitors bind very tightly to the protease.
C. the genes that code for serine proteases are organized in a similar fashion.
D. catalytic units exhibit two structural domains of dramatically different size.
E. conversion of zymogen to active enzyme usually involves one or more hydrolytic reactions.

Joanna Quigley

Numerade Educator

09:06

Problem 11

All of the following are believed to contribute to the stability of the deoxy or $\mathrm{T}$ conformation of hemoglobin except
A. a larger ionic radius of six-coordinated ferrous ion as compared to five-coordinated ion.
B. unstrained steric interaction of His $\mathrm{F} 8$ with the porphyrin ring when iron is above the plane.
C. interactions between the $\mathrm{FG}$ corner of one subunit and the $\mathrm{C}$ helix of the adjacent subunit.
D. ionic interactions.

Vishal Sharma

Numerade Educator

Problem 12

When hemoglobin is converted from the deoxy (T) form to oxyhemoglobin (R),
A. it becomes more acidic and releases protons.
B. carbamino formation is promoted.
C. binding of 2,3 -bisphosphoglycerate (BPG) is favored.
D. bound NO is transferred to glutathione.
E. all of the above.

Check back soon!

02:10

Problem 13

One of the adaptations to high altitude is an increase in the concentration of BPG. What effect does this have on a saturation versus $p \mathrm{O}_{2}$ curve? Why does increasing [BPG] increase the delivery of $\mathrm{O}_{2}$ to tissues?

Niamat Khuda

Numerade Educator

00:46

Problem 14

What would be the likely order of appearance of various immunoglobulins in response to a viral pathogen introduced via the nasal passages and subsequently into the blood?

Rikhil Makwana

Numerade Educator