How do enzymes reduce the amount of activation energy needed to make a chemical reaction go?

Urgent. the table shows the relative blood flow through some organs in the human body that is, the percentage of blood that flows through a given organ, through which organ(s) does all the blood flow? explain the effect of exercise on blood flow to skeletal muscles.

What terms describes being out of water after being submerged

Why has two different alleles for the same trait?