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The human heart is described as a double pump because blood passes through it and gets pumped out of it twice in a single circuit of the circulatory system. A normal heart is separated into two halves, ri...

It controls what enters and leaves the cell.

Synapses are the junctions between neurons. An electrical impulse travels down the first neuron and arrives at the presynaptic membrane. The presence of an electrical impulse causes chemicals called neuro...

Acid in stomach kills pathogens in food.Skin creates a barrier that microorganisms cannot enter through.Hairs in nose and ears that trap microorganisms.Mucus and cilia in the trachea and bronchi that trap...

The rate of reaction typically increases with temperature, as heat provides kinetic energy and more substrate-enzyme collisions. however, going above a certain temperature will cause enzymes to denature a...