Week 1, Lecture 1: Intro to Protein Structure

Question 1

How are peptide bonds formed?

Answer 1

amino acids through a condensation reaction to generate the primary sequence

Question 2

what are weak noncovalent interactions btwn AAs?

Answer 2

Hydrophobic interaction, and hydrogen bonds and ionic interactions

Question 3

what can change the ionization in the R groups, changing enzyme activity?

Answer 3

pH, heat

Question 4

what are Two most common forms of secondary structures?

Answer 4

alpha helices and beta-sheet

Question 5

Describe Myoglobin, type of protein and # of helices…

Answer 5

Globular protein, 8

Question 6

One type secondary structure make what type of protein?

Answer 6

Globular (most compactly folded), NOT fibrous

Question 7

Proteins that have similar folds often have similar…..

Answer 7

functions

Question 8

Myoglobin transports O2 to ____ for storage.

Answer 8

mitochondria

Question 9

Hemoglobin transports O2 from ___ to ___.

Answer 9

lungs to tissues

Question 10

What are some factors that might cause a protein to unfold?

Answer 10

Oxidative damage, organic solvents, changes in pH, or changes in temperature can cause proteins to denature

Question 11

Denaturation exposes hydrophobic residues which can then lead to….?

Answer 11

aggregation making the protein insoluble

eg. heinz bodies

Question 12

Can you name any diseases associated with protein aggregation?

Answer 12

Alzheimers, parkinsons, type II diabetes, cancer

Question 13

what happens in Prion diseases?

Answer 13

like Creutzfeldt-Jakob disease, proteins exhibit an increase in beta-sheets.

Question 14

Whats the result of An increase in beta-sheets?

Answer 14

leads to self-association and the formation of amyloid fibers

Question 15

Molecular chaperones are used by the cell for what?

Answer 15

to prevent the aggregation of misfolded proteins

Question 16

multiple polypeptide chains?

Answer 16

quaternary structure

Question 17

hemoglobin has how many alpha and beta chains?

Answer 17

[α(2):β(2)]

tetrameric hemeprotein

Question 18

Positive cooperativity results in what shape?

Answer 18

sigmoid shaped curve

Question 19

Is an allosteric modulator that promotes T state?

Answer 19

2,3-bisphosphoglycerate: at high altitudes

BPG levels increase

Question 20

what kind of posttranslational modifications can alter protein structure and function?

Answer 20

carbohydrate addition, lipid addition, regulation

Question 21

what happens when there is a decrease in glycosylation?

Answer 21

higher turn over of RBC

Question 22

what is a glycosylated protein called that can for a large protein aggregate?

Answer 22

advanced glycation end products

Question 23

Glycosylation of hemoglobin (irreversible) has little effect on function but glycosylation of collagen in the heart results in ???

Answer 23

cardiomyopathy

Question 24

Sickle cell anemia can be caused by a point mutation converting ____ to ____? what position? what chain?

Answer 24

glutamatic acid to valine at position 6 in β chain resulting in aggregation

Question 25

when is polymerization favorable?

Answer 25

concentration of HbS and is favored when hemoglobin is in the deoxygenated form

Question 26

The polymerization of hemoglobin results in ….?

Answer 26

sickling of the red blood cells and anemia

Question 27

sickling increases ____ of membrane and increasing _____?

Answer 27

Sickling increase permeability of membrane increasing intracellular Ca++

Question 28

Sickling of red blood cells can result in what effects?

Answer 28

occlusion of red blood vessels leading to organ damage and stroke, hypoxia&raquo_space;> necrosis

Question 29

Sickle cell disease onset occurs at approximately what age?

Answer 29

four months when hemoglobin switching occurs

Question 30

HbF has reduced

Affinity for?

Answer 30

BPG

Question 31

Glu6Val

Answer 31

HbS

Question 32

(α2β2S) sickle cell disease/anemia

Answer 32

HbSS

Question 33

(α2β2A) normal

Answer 33

HbAA

Question 34

sickle cell trait; only 1% of cells sickled

Answer 34

HbSA

Question 35

Glu6Lys

Answer 35

HbC

Question 36

compound heterozygous sickle cell disease

Answer 36

HbSC

Question 37

result from altered ratio of alpha: beta globin

Answer 37

Thalassemias