A mutation that confers a more advantageous phenotype to an organism, relative to individuals in the same population without the mutation, called as positive selection.

TLS Online TPP Program

#Id: 8211

#Unit 2. Cellular Organization

Autophagosome, or autophagic vesicle

formation of a flattened double-membrane cup-shaped structure that envelops a region of the cytosol or an entire organelle.

TLS Online TPP Program

#Id: 8212

#Unit 2. Cellular Organization

TLS Online TPP Program

#Id: 8213

#Unit 2. Cellular Organization

Autophagy occurs in the following sequence of steps:

Induction by activation of mTOR complex 1

• Nucleation of autophagosome formation by ATG9

• Closure of the membrane cup to form autophagosome

• Fusion of the autophagosome with lysosomes, catalyzed by SNAREs.

• Digestion of the inner membrane and the lumenal contents of the autophagosome

TLS Online TPP Program

#Id: 8215

#Unit 2. Cellular Organization

Autophagy can be either

• Nonselective autophagy

• Selective autophagy

TLS Online TPP Program

#Id: 8216

#Unit 2. Cellular Organization

In nonselective autophagy, a bulk portion of cytoplasm is sequestered in autophagosomes

TLS Online TPP Program

#Id: 8217

#Unit 2. Cellular Organization

In selective autophagy

specific cargo is packaged into autophagosomes that tend to contain little cytosol, mediates the degradation of worn out, or unwanted, mitochondria, peroxisomes, ribosomes, and ER; used to destroy invading microbes.