AM I RIGHT IF I SAY THAT THE מ AT THE BEGINNING OF THESE VERBS ACTUALLY TURNS ADJECTIVES INTO VERBS?
As Ynhockey wrote, it's not a general rule, but it's quite often the case. The pi'el template typically means "causing something to happen / to be". So if ישר is "straight", ליישר is "to make straight". Similarly יפה - מייפה, קצר -> מקצר, and many other examples. It's not a general rule, because there are also verbs in this template that don't have such an adjective counterpart - מנסה, משקר; and then many adjectives where the verb would go in another template, ארוך - האריך, שמן - השמין, גבוה - הגביה.