Change in environmental condition is not necessary for natural selection.

TLS Online TPP Program

#Id: 7933

#XL - Q Biochemistry

Signal sequences

contain one or more positively charged amino acids adjacent to a continuous stretch of 6–12 hydrophobic residues (known as the hydrophobic core)

TLS Online TPP Program

#Id: 7932

#XL - Q Biochemistry

Signal sequence

ER targeting sequence, located at the N-terminus of the protein

TLS Online TPP Program

#Id: 7931

#XL - Q Biochemistry

Microsomes

when cells are homogenized, the rough ER breaks up into small closed vesicles with ribosomes on the outside

TLS Online TPP Program

#Id: 7930

#XL - Q Biochemistry

Secretory pathway

pathway of protein trafficking that flows through the ER

TLS Online TPP Program

#Id: 7929

#XL - Q Biochemistry

The ER captures selected proteins from the cytosol as they are being synthesized. These are of two types:

Transmembrane proteins

Water-soluble proteins

TLS Online TPP Program

#Id: 7928

#XL - Q Biochemistry

Muscle cells have an abundant, modified smooth ER called the sarcoplasmic reticulum.

The release and reuptake of Ca2+ by the sarcoplasmic reticulum trigger myofibril contraction and relaxation, respectively