Cell division is incredibly tightly regulated (cancer  is described as an unregulated cell growth).In respect tothe cell division,there is a machinery that is a transitory state and this machinery is renewed every cell cycle. Key components of this machinery are: 1)      Spindle: is made of microtubules or cytoskeleton, centrioles, kinetochores and contractile ring. 2)      And […]

The plasma membrane:Is the boundary that separates, the living cell, from its surrounding and exhibits selective permeability, allowing some substances to cross it more easily than others. Cellular membranes are fluid mosaics of lipids and proteins – Phospholipids are the most abundant lipid in the plasma membrane -Phospholipids are amphipathic molecules, containing hydrophobic and hydrophilic […]

 All organisms are made of cells –          The cell is the simplest collection of matter that can live (reproduce) –          Cell structure is correlated to cellular function. –          All cells are related by their descent from earlier cells   Viruses are considered not to live because there reproduction depends on other organisms How do we […]