30 Questions
Which organelle is particularly abundant in cells with active lipid metabolism such as adipose cells and hepatocytes?
Smooth endoplasmic reticulum (SER)
Which chaperone is located on the inner side of the ER membrane and assists in pulling proteins into the ER lumen?
BiP chaperone
What is the major function of the smooth endoplasmic reticulum (SER) in eukaryotic cells?
Membrane lipid synthesis
Which organelle can the SER establish connections with?
Peroxisomes
In which cells is the smooth endoplasmic reticulum (SER) particularly abundant due to their production of steroid hormones?
Leydig cells in testis
What is a significant function of the SER in the liver?
Detoxification of lipid-soluble substances
What is the role of proteolysis in post-translational processing of proteins?
Specific cleavage of the polypeptide chain
Which organelle is responsible for synthesizing Ceramide, the precursor of Glycosphingolipids and Sphingomyelin?
Endoplasmic reticulum (ER)
What is the function of molecular chaperones in protein folding?
Facilitating the folding of other proteins into their native conformation
Which type of cleavage is necessary for translocating proteins across membranes?
Removal of the signal sequence
In post-translational processing, what happens after folding of proteins?
Glycosylation takes place
Which process is responsible for converting preproinsulin into insulin by removing an internal peptide?
Proteolysis
Which of the following statements about the differences between N-glycosylation and O-glycosylation is correct?
All of the above statements are correct.
Which of the following statements about the importance of glycosylation is not mentioned in the text?
Glycosylation plays a role in the formation of the extracellular matrix.
Which of the following statements about sulfation is correct?
Sulfation involves the addition of sulfate groups (SO₄²⁻) and typically occurs in proteoglycans.
Which of the following statements about phosphorylation is incorrect?
Phosphorylation occurs primarily in the nucleus and cytosol.
Which of the following statements about the transfer of monosaccharides is correct?
Monosaccharides are transferred bound to UDP or CMP.
Based on the information provided in the text, which of the following statements about the sugar chains in O-glycosylation is incorrect?
The sugar chains in O-glycosylation are longer than in N-glycosylation.
Which of the following is responsible for recognizing the signal peptide and initiating the co-translational translocation process?
SRP (Signal Recognition Particle)
What is the function of the SRP Receptor in the co-translational translocation pathway?
It facilitates the binding of the ribosome-SRP complex to the ER membrane
Which of the following is responsible for cleaving the signal peptide from the polypeptide chain during the co-translational translocation process?
Signal Peptidase
What is the function of the translocon channel in the co-translational translocation pathway?
It provides a channel for the polypeptide chain to be translocated into the ER lumen
What is the role of ribophorins in the co-translational translocation pathway?
They stabilize the binding of the ribosome to the ER membrane during translocation
Which of the following statements accurately describes the post-translational translocation pathway?
It involves the translocation of fully synthesized proteins into the ER lumen after their translation on free cytosolic ribosomes
What is the primary source of mature lysosomes (secondary lysosomes)?
Fusion of transport vesicles from the trans Golgi network containing acid hydrolases and endosomes with endocytosed molecules
What is the primary function of vesicles budding from the trans face of the Golgi apparatus?
Transporting proteins to their final destinations, such as the plasma membrane or organelle membranes
Which of the following statements best describes the role of motor proteins and microtubules in vesicular transport?
Motor proteins associated with microtubules facilitate the movement of transport vesicles to their destinations
What is the primary difference between constitutive secretion vesicles and stimulus-regulated secretion vesicles?
Constitutive secretion vesicles contain proteins that are continuously secreted, while stimulus-regulated secretion vesicles contain proteins that are secreted in response to specific stimuli
Which of the following statements accurately describes the sorting and packaging of proteins in the secretory pathway?
Newly synthesized proteins are sent to the cis Golgi on vesicles generated in the transitional endoplasmic reticulum
What is the final destination of transport vesicles containing membrane-anchored proteins?
Organelle membranes or the plasma membrane
Test your knowledge on the process of protein synthesis and secretion in cells, focusing on the role of ribophorins, signal peptides, and translocation. Understand how proteins are synthesized, targeted, and transported within cells.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
