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How is an action potential generated?

During rest, the outside of the neurone membrane is positively charged (relative to the inside). This is because approximately three sodium ions move out for every two potassium ions moving in through the so...
SI
Answered by Sabina I. • Biology tutor
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Use your knowledge of the actin and myosin mechanism of muscle contraction to explain how a vesicle might be "walked" along the cytoskeleton of a cell.

ATP binds the myosin head in its resting state. ATP is hydrolysed to ADP + Pi, releasing energy. This changes the conformation of the myosin head, cocking it. The myosin head reattaches to the actin molecule...
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Answered by Alex H. • Biology tutor
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Can you name the 3 different energy systems and give an example when each would be used?

Atp/pc system- ATP is hydrolysed into ADP + Pi, the free phosphate is used in exercises of 2-10s such as a powerlift.Anaerobic energy system- Glucose is the fuel for energy of glycolysis- used in exercises o...
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Answered by Seb G. • Biology tutor
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When a nerve impulse arrives at a synapse, it causes the release of neurotransmitter from vesicles in the presynaptic knob. Describe how.

When the action potential arrives at the presynaptic end of the neurone or nerve ending, the influx of ions along the axon body results in the depolarisation of the nerve cell and the presynaptic membrane. T...
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Answered by Philip A. • Biology tutor
3909 Views

Explain how cystic fibrosis affects digestion, gas exchange and reproduction.

Background information I would give to the student: This question is a perfect example which shows that if you really understand the topic, it becomes easier to remember the facts for the questions relating ...
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Answered by Shaswath G. • Biology tutor
10132 Views