#Question id: 1366
#Unit 4. Cell Communication and Cell Signaling
Mechano-transduction is the reciprocal interconversion of a mechanical force—or stimulus—and biochemical processes. These interconversions underlie a variety of biological activities, such as signaling, regulated gene expression, cell proliferation, cell migration, and interactions among cells and between cells and the ECM. Mechano-transduction in the context of cell-cell and cell-ECM interactions usually involves a cell-surface CAM or adhesion receptor that transmits mechanical force or biochemical information across the plasma membrane and one or more intracellular or extracellular mechano-sensors that respond to the mechanical stimulus by changing shape and activity. In Hypothetical model of the partial unfolding of a fibronectin type III, when that protein is subjected to mechanical force, following observations are-
A. Mechanical force generated within the cell by actin movement and transduce via multiple integrin adhesion receptors bound to the extracellular dimeric fibronectin can partially unfold the fibronectin.
B. The unfolding is thought to expose a putative, previously hidden binding site on fibronectin that has the potential to form β sheets with other fibronectin molecules, recruiting them to form fibronectin fibrils, and thus helping assemble the ECM.
According to observations which of the following protein act as mechano-sensor and mechano-transducer respectively?
#Question id: 3819
#Unit 3. Fundamental Processes
DNA replication is studied in a newly discovered bacterium. It takes 30 min for the bacterium to complete a round of replication at 37oC. A Meselson-Stahl-type experiment was performed. The bacteria were grown for several generations in 14N-medium and then switched to 15N-medium. The DNA molecules were then analyzed.
After one generation in 15N-medium, the DNA is denatured and analyzed in a CsCl gradient. If the single-stranded DNA forms two bands, one with heavy density and one with light density, what conclusion could be drawn about the mechanism of DNA replication in this bacterium?
#Question id: 2274
#Unit 2. Cellular Organization
Unlike those of prokaryotes, eukaryotic cell walls are composed of
#Question id: 31112
#Unit 2. Cellular Organization
#Question id: 18919
#Unit 13. Methods in Biology