Protein modifiction Flashcards
Why do proteins change shape? How do they do this?
Change from active/inactive via covalent bonds.
Why are disulfide bonds rare in most proteins?
They are very stable and hard to break
What are ubiquitins?
proteins that attach via isopeptide bonds, tagging other proteins for degradation.
What’s the deal with glycosilated proteins?
attaching sugars is a way to change the shape of hydroxyl containing peptides (serine, threonine) or Nitrogen containing (asparagine). Glycosilation often is permanent.
Which amino acids can be modified via glycosilation?
Serine, threonine, asparagine
Which amino acids can be modified via phosphorylation?
Serine, threonine, tyrosine
Which amino acids can be modified via farnestylation?
Cysteine. (adding of a lipid)
Which amino acids can be modified via methylation?
Asparagine and Lysine
Which amino acids can be modified via acetylation?
Lysine
Which amino acids can be modified via ubiquitination?
Lysine
Which amino acids can be modified via disulfide bonds?
Cysteine
What does allosteric mean?
Other space
What are proteasomes and where located?
digests proteins tagged with ubiquitin. cytosol and nucleus
What is the fate of proteins in organelles?
tagged with mannose-6-phosphate and degraded in lysosome.
What happens to extracellular proteins or proteinases?
Cells secrete proteinase enzymes( metalloproteinases) to digest them or proteinase inhibitors to stop this process.
