Post-transnational modification

What is ubiquitination?

• Ubiquitination is the process of removing ubiquitin from a target protein.

• Ubiquitination is the process of attaching ubiquitin to a target protein.

• Ubiquitination is the process of breaking down target proteins into smaller fragments.

• Ubiquitination is the process of synthesizing ubiquitin within a target protein.

What is the role of ubiquitin in protein degradation?

• Ubiquitin prevents protein degradation by the proteasome.

• Ubiquitin enhances protein stability by inhibiting degradation.

• Ubiquitin is not involved in protein degradation.

• Ubiquitin marks proteins for degradation by the proteasome.

Which enzyme is responsible for attaching ubiquitin to target proteins?

• ubiquitinase

• ubiquitin synthase

• ubiquitin transferase

• ubiquitin ligase

What is the function of the proteasome in ubiquitin-mediated protein degradation?

• The function of the proteasome in ubiquitin-mediated protein degradation is to stabilize ubiquitinated proteins.

• The function of the proteasome in ubiquitin-mediated protein degradation is to recognize and degrade ubiquitinated proteins.

• The function of the proteasome in ubiquitin-mediated protein degradation is to transport ubiquitinated proteins.

• The function of the proteasome in ubiquitin-mediated protein degradation is to synthesize ubiquitin.

Which enzyme is known as ubiquitin activating enzymes

• E2

• E1

• E3

• Chain of ubiquitins

Which enzyme is known as ubiquitin - conjugating enzymes

• E2

• E1

• E3

What are the steps involved in the ubiquitin-proteasome pathway?

• Ubiquitin activation, ubiquitin conjugation, proteasome recognition, proteasomal degradation, proteasome activation

• Ubiquitin activation, ubiquitin phosphorylation, ubiquitin ligation, proteasome recognition, proteasomal degradation

• The steps involved in the ubiquitin-proteasome pathway are ubiquitin activation, ubiquitin conjugation, ubiquitin ligation (bringing protein that is to be ubiquitinated), proteasome recognition, and proteasome degradation.

• Ubiquitin phosphorylation, ubiquitin conjugation, proteasome recognition, proteasomal degradation

E1 bind to one of the------of ubiquitin

• Cysteine residues

• Lysine residue

• Isoleucine

• Glycine residues

Ubiquitin is a -----amino acids exists in all eukaryotic cells

• 74 amino acids

• 76 amino acids

• 72 amino acids

• 70 amino acids

Autophagy is a cellular processes isolating cytoplasmic components that can be directed to the -----for degradation

• Peroxisome

• Lysosome

• cytoplasm

• Mitochondria