The Mechanism of Insulin Biosynthesis by Pancreatic β-cells

The video tutorial explains the process of insulin maturation, detailing the roles of the rough ER and Golgi apparatus. It covers the transformation from preproinsulin to mature insulin, highlighting the importance of signal peptides, disulfide bridges, and the cleavage of the C peptide. The tutorial also discusses the secretion of insulin in response to glucose levels in the blood.

What organelles are primarily involved in the maturation of insulin?

• Mitochondria and Lysosomes

• Rough ER and Golgi Apparatus

• Nucleus and Ribosomes

• Smooth ER and Peroxisomes

What is the initial form of insulin produced by the ribosome?

• Mature Insulin

• Proinsulin

• Preproinsulin

• C-peptide

Which process is necessary for the formation of disulfide bridges in insulin?

• Reduction

• Oxidation

• Hydrolysis

• Phosphorylation

What is the role of the signal peptide in insulin processing?

• It is part of the mature insulin structure.

• It signals the protein to remain in the cytosol.

• It directs the protein to the rough ER lumen.

• It helps in the formation of disulfide bridges.

Which enzyme is responsible for cleaving the signal peptide?

• Ribosome

• Prohormone Convertase

• Carboxypeptidase E

• SEC 11

What is the final step in the maturation of insulin?

• Cleavage of the signal peptide

• Translation of mRNA

• Formation of disulfide bridges

• Removal of C-terminal amino acids

What triggers the release of insulin into the blood?

• The presence of glucagon

• The amount of ATP in the cell

• The concentration of sodium ions

• The level of intracellular calcium