Answer to Question 1
Thiamin plays an important role in the synthesis of deoxyribonucleic acid (DNA), ribonucleic acid (RNA), and triglycerides. To aid in energy synthesis, thiamin acts as a coenzyme, meaning that an enzyme will not function unless thiamin is present. Without thiamin acting as a coenzyme, the enzymes that make DNA and RNA cannot work, and protein synthesis is halted. As a result, cell division is impeded because the genetic material (DNA and RNA) cannot be replicated.
Answer to Question 2
Vitamin A has many important functions beyond vision. Vitamin A plays an important role in cell differentiation, the process by which a nonspecialized, immature cell type becomes a specialized, mature cell type. Vitamin A is also critical for growth and reproduction, and it has a variety of immunological functions. These include the maintenance of protective barriers (such as skin and those that line organs) and the production of immune cells (such as those that produce antibodies). Preformed vitamin A is also essential for healthy bones.
Cell signalling via integrins in anchoring junctions
Comet Tempel 1 67 seconds after colliding with the Deep Impact probe.
Sickle cell anemia. The clinical manifestations of sickle cell anemia result from pathologic changes
Cell kill and chemotherapy.
A prokaryotic cell
The generation, removal, and role of reactive oxygen species (ROS) in cell injury