Post-Translational Modifications — Flashcards

Flashcard 1: In the _____, post-translational O-glycosylation adds sugars onto the amino acids serine and threonine

Answer: Golgi apparatus

Flashcard 2: Collagen Synthesis: After the collagen pro-alpha chains are synthesized, specific residues of the amino acids _____ and lysine are hydroxylated

Answer: proline

Flashcard 3: Microtubules grow _____ and collapse quickly (speed)

Answer: slowly

Flashcard 4: In the Golgi apparatus, _____ is added to proteins for trafficking to lysosomes

Answer: mannose-6-phosphate

Flashcard 5: The direction of protein synthesis is _____-terminus to C-terminus

Answer: N

Flashcard 6: Curve A indicates which compound? _____

Answer: Myoglobin

Flashcard 7: The given image represents a _____ which is a secondary structure of proteins.

Answer: beta-sheet

Flashcard 8: egg white forms _____% weight of egg

Answer: 60

Extra: 

Flashcard 9: Serum _____ is the most sensitive indicator for protein estimation (nutritional status).

Answer: pre-albumin

Extra: • **Pre-albumin (Transthyretin):** Most sensitive indicator (Half-life ≈ 2 days). • **Albumin:** Indicator of chronic nutritional status (Half-life ≈ 20 days). • **Retinol-binding protein:** Even shorter half-life (~12 hours) but less commonly tested. Note: Albumin is a negative acute-phase reactant, meaning its levels drop during inflammation regardless of nutritional status.

Flashcard 10: Collagen Synthesis: Once in the extracellular space, cleavage of disulfide-rich terminal regions of procollagen by _____ forms the insoluble tropocollagen

Answer: procollagen peptidase