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What is an allergy?

Allergy is the result of the immune system overreacting to harmless stimuli in the environment. Examples of stimuli or 'allergens' include pollen, dust, eggs and milk. The body recognises these harmless alle...
SK
Answered by Saadiyah K. • Biology tutor
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What is peristalsis?

Peristalsis is the mechanism by which gut muscles contract. There are two main types of muscle in the gut: -longitudinal -circular Together, these muscles contract to create waves of movement. This allows fo...
SK
Answered by Saadiyah K. • Biology tutor
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Explain the characteristics of enzymes and the lock and key theory of enzyme action. Explain the role of enzymes in catabolic and anabolic reactions.

1) enzymes are biological catalysts that will speed up reactions by reducing activation energy for the reaction. 2) Lock and key theory concerns how the enzyme (lock) only forms a reactive complex with a spe...
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Answered by James B. • Biology tutor
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How does filtration through the kidney work?

There are 3 key stages in filtration through the Kidney: Firstly, blood is pushed through a tubular structure called the glomerulus - imagine a bowl of noodles. The pressure of the blood in the glomerulus ca...
AP
Answered by Alastair P. • Biology tutor
4185 Views

Describe the changes at the cell membrane of a neuron during an action potential.

At rest the membrane potential is -70mV . This is due to the Na + /K + pump, which actively transports 3 Na + ions out of the cell for every 2 K + ions in. Therefore there is a net negative charge inside the...
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Answered by Alex N. • Biology tutor
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