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

TLS Online TPP Program

#Id: 8034

#Section 2: General Biology

Nonpolar amino acids have three ionisations zones

1. 1--------pK1 – charge +1

2. pK1---------pK2 charge 0

3. pK2---------14 charge -1

TLS Online TPP Program

#Id: 8033

#Section 2: General Biology

Glycine & Proline are relatively polar considering negative hydropathy index (-0.4 & -1.6) comparing to other nonpolar amino acids.

TLS Online TPP Program

#Id: 8032

#Section 2: General Biology

Ornithine and citrulline, which are not found in proteins, are intermediates in the biosynthesis of arginine and in the urea cycle.

TLS Online TPP Program

#Id: 8031

#Section 2: General Biology

TLS Online TPP Program

#Id: 8030

#Section 2: General Biology

Desmosine is formed from four Lys residues

TLS Online TPP Program

#Id: 8029

#Section 2: General Biology