Muscle Enzymes: Creatine Kinase and Aldolase

Magnesium ions (Mg2+) are crucial for creatine kinase activity and form complexes with ATP and ADP, serving as obligate activating ions.

Creatine kinase plays a crucial role in cellular energy metabolism, particularly in muscle cells, by catalyzing the reversible phosphorylation of creatine by ATP.

The forward reaction of creatine kinase, which generates ATP from creatine phosphate, is favored at a pH of 9.0.

<p>Metal ions like manganese (Mn2+), calcium (Ca2+), zinc (Zn2+), and copper (Cu2+) inhibit creatine kinase activity.</p> Signup and view all the answers

<p>Creatine kinase is a dimeric enzyme with a molecular weight of 82 kDa.</p> Signup and view all the answers

<p>During muscle contraction, creatine kinase catalyzes the rephosphorylation of ADP back to ATP using creatine phosphate as a reservoir of high-energy phosphate, essential for sustaining muscle function during periods of high energy demand.</p> Signup and view all the answers

<p>Excess ADP, citrate, fluoride, nitrate, acetate, iodide, bromide, malonate, L-thyroxine, urate, cystine, chloride ions, and sulfate ions</p> Signup and view all the answers

<p>To prevent inhibition of CK activity</p> Signup and view all the answers

<p>N-acetylcysteine, dithiothreitol (Cleland reagent), and glutathione</p> Signup and view all the answers

<p>High solubility and typically used at a final concentration of 20 mmol/L</p> Signup and view all the answers

<p>Striated muscle and heart tissue</p> Signup and view all the answers

<p>Brain, smooth muscles of the gastrointestinal tract, and urinary bladder</p> Signup and view all the answers

<p>Liver and erythrocytes</p> Signup and view all the answers

<p>Around 40 kDa</p> Signup and view all the answers

<p>Three</p> Signup and view all the answers

<p>Using their electrophoretic mobility as a basis</p> Signup and view all the answers