Amino Acids

Question 0

With OH as R group

Answer 0

Serine

ThreonineTyrosine

Question 1

Amino acids with aliphatic side chains

Answer 1

Glycine
Alanine
Valine
Leucine
Isoleucine

Question 2

With sulfur atoms

Answer 2

Cysteine

Methionine

Question 3

With imino acid side chain

Answer 3

Proline

Question 4

Molecules that contain an equal number of ioniz-able groups of opposite charge and that therefore bearno net charge are termed ______

Answer 4

Zwitterions

Question 5

Both D-amino acids and non-α-amino acids occurin nature, but only _- α-amino acids are present inproteins.

Answer 5

L configuration

Question 6

primary structure of a peptideis its amino acid sequence, starting from the _____-terminal residue.

Answer 6

Amino

Question 7

are compact, are roughly sphericalor ovoid in shape, and have axial ratios (the ratio oftheir shortest to longest dimensions) of not over 3..

Answer 7

Globular proteins

Question 8

Primary structure, the sequence of the aminoacids in a polypeptide chain;
secondary structure, thefolding of short (3- to 30-residue), contiguous segmentsof polypeptide into geometrically ordered units;
ter-tiary structure, the three-dimensional assembly of sec-ondary structural units to form larger functional unitssuch as the mature polypeptide and its component do-mains;
quaternary structure, the number andtypes of polypeptide units of oligomeric proteins andtheir spatial arrangement.

Which among is considered false?

Answer 8

None of the above

Question 9

proteins participate in the folding of overhalf of mammalian proteins.

Answer 9

Chaperones. Heast shock proteins (hsp)

Question 10

Refolding or misfolding of another protein endogenousto human brain tissue, β-amyloid, is also a prominentfeature of ____

Answer 10

Alzheimer’s disease

Question 11

most abundant of the fibrous proteinsthat constitute more than 25% of the protein mass inthe human body.

Answer 11

Collagen

Question 12

Prions—protein particles that lack nucleic acid—cause fatal transmissible spongiform encephalopa-thies such as

Answer 12

Creutzfeldt-Jakob disease, scrapie, kuru, and bovine spongiform encephalopathy.

Question 13

cyclictetrapyrrole consisting of four molecules of pyrrolelinked by α-methylene bridges

Answer 13

Heme

Question 14

subunit compositionof the principal hemoglobins are
α β (HbA; normaladult hemoglobin),
α2γ2 (HbF; fetal hemoglobin),
α2 2 2S2(HbS; sickle cell hemoglobin),
α δ
2 2 (HbA2; aminor adult hemoglobin).
Which of the enumerated has resistance to malarial infection?

Answer 14

Sickle hemoglobin

Question 15

Which has coopertavie binding with oxygen?

Hemoglobin
Myoglobin

Answer 15

Hemoglobin

Question 16

Deoxyhemoglobin binds one proton for every twoO2 molecules released, contributing significantly to thebuffering capacity of blood. The somewhat lower pH ofperipheral tissues, aided by carbamation, stabilizes theT state and thus enhances the delivery of O2. In thelungs, the process reverses. As O2 binds to deoxyhemo-globin, protons are released and combine with bicar-bonate to form carbonic acid. Dehydration of H2CO3,catalyzed by carbonic anhydrase, forms CO2, which isexhaled. Binding of oxygen thus drives the exhalationof CO2 (Figure 6–9).This reciprocal coupling of protonand O2 binding is termed _____

Answer 16

bohr effect

Question 17

transition of hemoglobin from theT (taut)state to the R (relaxed) state. Which is low oxygen affinity?

Answer 17

Taut or T form

Question 18

Mutations (eg, hemoglobin Chesapeake) that favorthe R state increase O2 affinity. These hemoglobinstherefore fail to deliver adequate O2 to peripheral tis-sues. The resulting tissue hypoxia leads to _____, an increased concentration of erythrocytes.

Answer 18

Polycythemia

Question 19

Mutations in the genes that encode the α or β subunitsof hemoglobin potentially can affect its biologic func-tion. However, almost all of the over 800 known mu-tant human hemoglobins are both extremely rare andbenign, presenting no clinical abnormalities. When amutation does compromise biologic function, the con-dition is termed a _____

Answer 19

Hemoglobinopathy

Question 20

Two questions: In HbS, the nonpolar amino acid ____ has replacedthe polar surface residue Glu6 of the β subunit, gener-ating a hydrophobic “sticky patch” on the surface ofthe β subunit of both oxyHbS and deoxyHbS. If HbC glu6 is substited by amino acid ____

Answer 20

HbS: valine
HbC: lysine

Question 21

Following massive crush injury, myoglobin releasedfrom damaged muscle fibers colors the urine dark red urine termes as:

Answer 21

Myoglobinuria

Question 22

When blood glucose enters the erythrocytes it glycosy-lates the ε-amino group of lysine residues and theamino terminals of hemoglobin. The fraction of hemo-globin _______, normally about 5%, is proportion-ate to blood glucose concentration. Since the half-life ofan erythrocyte is typically 60 days, the level of _____reflects the mean blood glu-cose concentration over the preceding 6–8 weeks.Measurement of _____ therefore provides valuable in-formation for management of diabetes mellitus.

Answer 22

HbA1c