IRF740 MOSET question

You're looking at the Gate Threshold voltage Vgs(th). That tells you that it will START to conduct somewhere between 2 and 4V.

The more interesting parameter is Rds(on), the resistance when fully on. If that is only stated at 10V then the chances of it being fully on at 3.7V or even 5V are remote. Logic level MOSFETs usually give this parameter at 4.5V or even 2.8V. They're the ones that are useful with Arduinos.

Steve