<span>Amylase needs an optimum pH for its activity. It is in the range of 6-7. Below or above pH will denature this enzyme. The pH level is optimum for this enzyme in the mouth and hence it catalyses the break down of sugar. The pH level of stomach is lower than its optimum level duet to the activity of gastric acid. Hence the enzyme becomes inactive in the stomach.</span>
When cells communicate by the signaling process, one cell produces a signaling molecule that must be received by the signal receptor on or in the responding cell. Signaling molecules are often called ligands, a general term for molecules that bind specifically to other molecules (such as receptors).
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The answer is; A
When an impulse from the motor neuron reached the neuromuscular junction, the voltage-dependent calcium channels are activated and the neurotransmitter released from the presynaptic cleft. When the neurotransmitter binds to their receptors on the sarcolemma, the muscle fibers become depolarised; the calcium is released from their vesicles. The Ca2+ ions are important in the power stroke because they bind to troponin. Upon binding calcium, troponin moves tropomyosin away from the myosin-binding sites on actin. Powered by the energy from ATP molecule, the myosin is able to bind on the actin and slides over the actin filament.
Answer:
high elevation with nearly horizontal layers of bedrock
Explanation:
A plateau is a an area of relatively high ground.
