Proteins and Quality Control

Question 1

What Are Molecular Chaperones?

Answer 1

proteins that assist the covalent folding or unfolding and the assembly or disassembly of other macromolecular structures

Question 2

What are Chaperonins?

Answer 2

Proteins that facilitate folding of mis folded proteins

Question 3

Acetylation

Answer 3

process where an acetyl functional group is transferred from one molecule (in this case, Acetyl-Coenzyme A) to another

Question 4

Phosphorylation

Answer 4

post-translational modification of proteins in which an amino acid residue is phosphorylated by a protein kinase by the addition of a covalently bound phosphate group

Question 5

Glycosylation

Answer 5

reaction in which a carbohydrate, i.e. a glycosyl donor, is attached to a hydroxyl or other functional group of another molecule

Question 6

Hydroxylation

Answer 6

chemical process that introduces a hydroxyl group (-OH) into an organic compound

Question 7

Methylation

Answer 7

a process by which methyl groups are added to the DNA molecule. Methylation can change the activity of a DNA segment without changing the sequence

Question 8

Carboxylation

Answer 8

a chemical reaction in which a carboxylic acid group is introduced in a substrate

Question 9

What are some forms of protein Modifications?

Answer 9

Acetylation, Phosphorylation, Glycosylation, Hydroxylation, Methylation, Carboxylation

Question 10

What are 3 ways Proteins are Degradated?

Answer 10

1. Within lysosomes
2. Degestive proteases
3. Ubiquitin-mediated protein degradation

Question 11

What is Ubiquitin?

Answer 11

is a small regulatory protein that has been found in almost all tissues. The addition of ubiquitin to a substrate protein is called ubiquitination or ubiquitylation

Question 12

How can Ubiquitin effect proteins?

Answer 12

Ubiquitination can affect proteins in many ways: it can signal for their degradation via the proteasome, alter their cellular location, affect their activity, and promote or prevent protein interactions

Question 13

Sepcificity

Answer 13

ability of one protein to bind one molecule in preference to another

Question 14

Affinity

Answer 14

strength of binding

Question 15

What is an example of an Enzyme working as a catalyst?

Answer 15

Kinases

Question 16

Kinases

Answer 16

1. Contain an ATP-binding site which is highly conserved

2. Transfer phosphate groups to proteins to induce changes in protein structure

Question 17

What is need for High affinity interactions to take place?

Answer 17

The binding site of the protein must be complementary to the ligand molecule

Question 18

CDRs

Answer 18

Complementarity-determining Regions of antibodies that are highly variable

Question 19

Epitope

Answer 19

portion of a protein bound by an antibody

Question 20

Protein Scaffolds

Answer 20

known to interact and/or bind with multiple members of a signaling pathway, tethering them into complexes

Question 21

What are some examples of molecular motors?

Answer 21

Ribosomes, Myosin, Kinesins, Dynein, RNA polymerase and DNA polymerase

Question 22

How does the Kinase/Phosphatase Switch Work?

Answer 22

Protein Kinase Phosphorylates the switch proteins using ATP causing it to go inactive. Protein Phosphatase dephosphorylates the switch proteins using H20 causing it to become active