A researcher is studying eukaryotic cells that shows an abnormal pattern of surface glycosylation. The researcher determines that these cells have normal levels of glycolipids and integral membrane proteins with O-linked glycosylation. The researcher discovers that there are no N-linked glycosylated proteins on the cell surface and unusually high levels of glycosylated in the ER membrane. What is a reasonable hypothesis to explain this observation?
A. the cell is defective in synthesizing of carbohydrates
B. the cell has a defect in its ER localization signal
C. the cell is defective in assembling carbohydrate trees
D. the cell has a defect in its protein sorting pathway
E. the cell has a defective oligosaccharide transferase
Answer: E
You might also like to view...
Drug therapies that target only cancer cells rather than all dividing cells in the body stop the growth of cancer by blocking the action of ____________________ proteins on the growth and division on malignant cells
Fill in the blank(s) with correct word
The first eukaryotic genome to be elucidated was from ____
a. Escherichia coli b. Caenorhabditis elegans c. Drosophila melanogaster d. Saccharomyces cerevisiae e. Schizosaccharomyces pombe
As pyruvate is prepared for the citric acid cycle, it undergoes a process of
A) reductive carboxylation. B) oxidative decarboxylation. C) oxidative carboxylation. D) reductive decarboxylation. E) substrate level phosphorylation.
Ritalin, like cocaine and amphetamines, acts by increasing the concentration of which neurotransmitter in neuronal synapses?
A) dopamine B) serotonin C) acetylcholine D) gamma-aminobutyric acid (GABA)