6. why do we need to breathe all day and all night?

The normal shape of an enzyme is as shown in structure a. if the enzyme’s shape changes to that shown in structure b, what are two consequences of this change?

Aplant may open end close its stomata to prevent excess water loss and maintain

Which of the following best describes the purpose of the parathyroid hormone? a. it decreases the blood calcium level and decreases blood phosphorus level. b. it decreases the blood calcium level and increases the blood phosphorus level. c. it increases the blood calcium level and increases blood phosphorus level. d. it increases the blood calcium level and decreases blood phosphorus level.