With Picmonic, facts become pictures. We've taken what the science shows - image mnemonics work - but we've boosted the effectiveness by building and associating memorable characters, interesting audio stories, and built-in quizzing.
DOWNLOAD PDFPreproinsulin is a proinsulin molecule with a signal peptide attached to its N-terminus. It is a biologically inactive precursor of insulin.
Removal of the signal peptide from preproinsulin results in the formation of proinsulin in the rough endoplasmic reticulum of pancreatic beta cells.
Removal of the signal peptide from N-terminus of preproinsulin results in the formation of proinsulin.
Processing of proinsulin in the Golgi apparatus results in the formation of biologically active insulin. This processing involves the removal of the C-peptide and connection of the A- and B-chains through disulfide bonds.
Synthesis, storage, and release of insulin mainly take place in beta cells of the pancreas. Pancreatic beta cells are located in the islets of Langerhans. They make up the majority of the cells in the islets.
C-peptide is a short polypeptide that connects insulin's A-chain to its B-chain in the proinsulin molecule. C-peptide is released with insulin after the cleavage of proinsulin. Hence, C-peptide is a byproduct of endogenous insulin synthesis. This is important clinically as increased C-peptide levels reflect an increased endogenous production of insulin (e.g., insulinoma, sulfonylurea use). In contrast, exogenous insulin administration (e.g., a patient who overdosed on injected insulin) won't result in the elevation of C-peptide levels as exogenous insulin lacks C-peptide.
An insulinoma is a tumor of the pancreas that is derived from the beta cells of the pancreas. This tumor secretes excessive amounts of insulin and can result in hypoglycemia. As the insulin is synthesized endogenously, C-peptide levels will be elevated.
Sulfonylureas (e.g. glyburide, glipizide) are medications used to treat diabetes mellitus. These drugs help to increase endogenous pancreatic secretion of insulin so insulin and C-peptide levels in a patient taking sulfonylureas should be high-normal or elevated.
Surreptitious insulin use is characterized by high insulin levels and low C-peptide levels. Exogenous insulin doesn't contain C-peptide, and its ingestion results in increased total insulin levels, which suppresses the production of endogenous insulin due to feedback inhibition, hence C-peptide levels will be low.
Picmonic's rapid review multiple-choice quiz allows you to assess your knowledge.
*Average video play time: 2-3 minutes
Unforgettable characters with concise but impactful videos (2-4 min each)
Over 2,040,000 students use Picmonicâs picture mnemonics to improve knowledge, retention, and exam performance.
Picmonic for Medicine (MD/DO) covers information that is relevant to your entire Medicine (MD/DO) education. Whether youâre studying for your classes or getting ready to conquer the USMLE Step 1, USMLE Step 2 CK, COMLEX Level 1, or COMLEX Level 2, weâre here to help.
Research shows that students who use Picmonic see a 331% improvement in memory retention and a 50% improvement in test scores.