Many plants also contain unusual amino acids, called nonprotein amino acids, these Nonprotein amino acids are often very similar to common protein amino acids. Canavanine, for example, is a close analog of_____A______, and azetidine-2-carboxylic acid has a structure very much like that of_____B________.

#Question id: 3776

#Unit 3. Fundamental Processes

Telomere shortening puts a limit on the number of times a cell can divide. Research has shown that telomerase can extend the life span of cultured human cells. How might adding telomerase affect cellular aging?

#Question id: 1373

#Unit 4. Cell Communication and Cell Signaling

Following statements are regarding to cholera toxins which can affect the junction’s activity.

a. Toxins produced by Vibrio cholerae, the enteric bacterium that causes cholera, alter the permeability barrier of the intestinal epithelium by altering the composition or activity of gap junctions.

b. Vibrio cholerae also releases a protease that disrupts tight junctions by degrading the extracellular domain of occludin.

c. Toxin-induced changes in tight-junction permeability (increased paracellular transport) and in protein-mediated ion pumping (decreased transcellular transport) can result in massive losses of internal body ions and water into the gastrointestinal tract, which in turn leads to diarrhea and potentially lethal dehydration.

d. Toxin-induced changes in tight-junction permeability (decreased paracellular transport) and in protein-mediated ion pumping (increased transcellular transport) can result in massive losses of internal body ions and water into the gastrointestinal tract, which in turn leads to diarrhea and potentially lethal dehydration.

Which of the following statements are correct?

#Question id: 10965

#Unit 7. System Physiology – Animal

Which of the following is a TRUE statement?

#Question id: 26346

#Unit 2. Cellular Organization

Choose the correct statement

#Question id: 18593

#Unit 11. Evolution and Behavior