Provided that there's no diagram, most molecules have particular areas on the molecules, called the "active area" that act as a lock to a particular substrate's molecular structure, providing the key.
An enzyme's active area is only able to be "unlocked" by a certain substrate's "key".
A calcium deficient would:
C) prevent contraction by preventing myosin from binding to actin
**I'm assuming that you mean a severe lack of calcium where there's not enough to bind to troponins.
Answer:
Guard cells
Explanation:
Guard cells are can be described as a special group of plant cells that are located or can be found in the epidermis of plants. They come in the shape of a kidney.
They help to control the rate at which air moves in and out of the plant, the is achieved by periodically opening the stoma and blocking it back. They are also responsible for the regulation of water movement in and out of the plant.
This essential material in which the guard cell regulates/ control is an important part of plant photosynthesis, therefore they play an important role in the process through which plants manufacture their food.
Good luck, I have no clue
