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UBC BIOL 200 - UNIT 4:
ENDOMEMBRANES 2026 LATEST
QUESTIONS AND ANSWERS| ACE
YOUR GRADES.
What kind of proteins and lipids are secreted during constutive
secretion? - correct answer --Proteins and lipids that form the
plasma membrane
-Proteins and glycoproteins that form part of the extracellular
matrix
Describe the lysosomal pathway - correct answer -(1) The
targeting sequence is recognized by mannose-6-phosphate
receptors in the trans Golgi network
(2) They get packaged into clathrin-coated vesicles at the TGN
and sent to the endosome
(3) Fuse with the late endosome
(4) Lysosomal proteins are separated from their receptors
(5) Lysosomal protein travels with the endosome to the
lysosomes and the receptors are returned to the TGN
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What is the targeting sequence used by the cell for lysosomes? -
correct answer -Mannose-6-phosphate
Why are lysosomal proteins separated from their receptors? -
correct answer -Increased acidity in the endosome
What is the optimum pH for digestive enzymes? - correct answer
-pH 5
What maintains the low pH of the lysosomes? - correct answer -
Protein pumps in the lysosomal membrane
What are primary and secondary lysosomes? - correct answer -
Primary- newly made lysosomes
Secondary- lysosomes that have fused with the endosome and
endosome contents have been digested
How can secondary lysosomes be recycled? - correct answer -
Fusing with endosomes
, Page | 3
How are lysosomal receptors returned to the Golgi? - correct
answer -They are returned to the trans-Golgi via retrograde
transport
What is phagocytosis? - correct answer -Ingestion of large
particles by cells
What is pinocytosis? - correct answer -Ingestion of fluid and
macromolecules via small vesicles
What is receptor-mediated endocytosis? - correct answer -
Ingestion of specific molecules bound to receptors on the cell
surface that are clathrin coated
Describe the process of phagocytosis - correct answer -(1)
Large particles are taken by membrane limited vesicles in
response to cell surface receptors
(2) Calcium channels open
(3) Increase in calcium ions triggers formation of phagosome
UBC BIOL 200 - UNIT 4:
ENDOMEMBRANES 2026 LATEST
QUESTIONS AND ANSWERS| ACE
YOUR GRADES.
What kind of proteins and lipids are secreted during constutive
secretion? - correct answer --Proteins and lipids that form the
plasma membrane
-Proteins and glycoproteins that form part of the extracellular
matrix
Describe the lysosomal pathway - correct answer -(1) The
targeting sequence is recognized by mannose-6-phosphate
receptors in the trans Golgi network
(2) They get packaged into clathrin-coated vesicles at the TGN
and sent to the endosome
(3) Fuse with the late endosome
(4) Lysosomal proteins are separated from their receptors
(5) Lysosomal protein travels with the endosome to the
lysosomes and the receptors are returned to the TGN
, Page | 2
What is the targeting sequence used by the cell for lysosomes? -
correct answer -Mannose-6-phosphate
Why are lysosomal proteins separated from their receptors? -
correct answer -Increased acidity in the endosome
What is the optimum pH for digestive enzymes? - correct answer
-pH 5
What maintains the low pH of the lysosomes? - correct answer -
Protein pumps in the lysosomal membrane
What are primary and secondary lysosomes? - correct answer -
Primary- newly made lysosomes
Secondary- lysosomes that have fused with the endosome and
endosome contents have been digested
How can secondary lysosomes be recycled? - correct answer -
Fusing with endosomes
, Page | 3
How are lysosomal receptors returned to the Golgi? - correct
answer -They are returned to the trans-Golgi via retrograde
transport
What is phagocytosis? - correct answer -Ingestion of large
particles by cells
What is pinocytosis? - correct answer -Ingestion of fluid and
macromolecules via small vesicles
What is receptor-mediated endocytosis? - correct answer -
Ingestion of specific molecules bound to receptors on the cell
surface that are clathrin coated
Describe the process of phagocytosis - correct answer -(1)
Large particles are taken by membrane limited vesicles in
response to cell surface receptors
(2) Calcium channels open
(3) Increase in calcium ions triggers formation of phagosome
