Extrinsic Pathway of Apoptosis (The Receptor-Mediated Programmed Cell Death Pathway) In the extrinsic pathway of apoptosis, the death-inducing signal for the programmed cell death is triggered by an external stimulus. For receiving such an external death-inducing signal, the cell possesses plasma membrane receptors specific to each stimulus and thus the […]
Two Types of Apoptosis In the previous post, we have discussed the characteristic features and significance of programmed cell death or apoptosis. As we discussed, the stimuli for the execution of programmed cell death can be of internal or external to the apoptotic cell. Based on the source of stimuli, […]
What is Apoptosis? Why apoptosis is known as the ‘Programmed Cell Death’? The total number of cells in an organ or organism is fundamentally fixed to a specific range in all multicellular organisms. In every multi-cellular organism, the cell number is effectively controlled by two strategies- (a) by regulating cell […]
Flagella vs Fimbriae vs Pili of Bacteria What are cell surface appendages? Cell surface appendages (aka filamentous appendages or Extracellular Structure of Bacteria) are proteinaceous tubular or fibrous structures found on the surface of bacterial cells. They extend from the surface of the bacterial cell wall and can have many […]
Endospore vs Vegetative Cell Bacterial endospores are special tough, dormant and resistant spores produced by some Gram-positive bacteria of during unfavorable environmental conditions. They help the bacteria to endure the unfavorable conditions. The endospores are structurally, metabolically and functionally very different from bacterial vegetative cells. In the previous post, we […]