Answer: Bones cells secrete an extracellular matrix that when combined with minerals becomes rock hard.
Explanation:
A pulse with unpredictable pattern is termed as an <em />irregularly irregular pulse. This kind of pulse coincides with an irregularly irregular heart rhythm seen in those with severe arrhythmias such as 3rd degree AV block. In contrast, there is a pulse that is irregular but has a predictable pattern termed as regularly irregular.
They help with metabolism and can act as enzymes or carriers and hormones. Protein has amino acids within it