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What is active transport and how is it different from diffusion?

Active transport is the movement of ions or molecules across a cell membrane against a concentration gradient. It requires energy in the form of ATP.Active transport is different to diffusion as diffusion is...
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Answered by Stella W. • Biology tutor
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What is an enzyme and explain its mechanism of action

An enzyme is a protein that is used as a catalyst in a reaction within an organism. This is used in such a way that it lowers the energy requirement for a specific reaction to occur and this could either be ...
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Answered by Michael B. • Biology tutor
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Describe the ionic basis of an action potential, and how this is reflected on the cell's membrane potential (6 marks)

At rest (steady state) there is a greater concentration of Na+ ions and a smaller concentration of K+ ions on the outside compared to the inside of the cell, and the membrane potential is about -70mV. Upon d...
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What causes the heart to contract?

This type of question requires careful explanation and therefore would need to be broken down into chunks. One of the reasons for this is that it may be completely new concepts for students. My answer to a s...
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Answered by Saajan R. • Biology tutor
5502 Views

Explain the nervous pathway reflex when touching something hot (5 marks)

The stimulus/heat is detected by receptors in the hand It sends an impulse via sensory neurones to the spinal cord/CNSChemicals are transmitted via the synapses and diffuses across the gap The impulses trave...
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Answered by Lia H. • Biology tutor
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