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Explain how an action potential is generated

At rest the neuron has a charge of -70mV, this is called the resting membrane potential and is caused by different concentrations of ions inside and out of the cell. At rest, potassium ions accumulate inside...
CS
Answered by Charlotte S. • Biology tutor
4326 Views

Describe and explain how cell fractionation and ultracentrifugation can be used to isolate mitochondria from a suspension of animal cells.

It is possible to separate out the different organelles of a cell by spinning a homogenised solution of them at different speeds using an ultracentrifuge. The cells must first be placed in a cold, isotonic b...
KW
Answered by Kate W. • Biology tutor
38308 Views

What is the significance of performing mouth-to-mouth breaths during CPR?

Exhaled air contains a higher percentage of CO2 than inhaled air, due to it being a waste product of respiration. By breathing excess CO2 into the patient, the blood acidity will decrease and will be detecte...
PD
Answered by Phoebe D. • Biology tutor
3350 Views

Explain the mechanism by which DNA is replicated

DNA is replicated by semi-conservative replication meaning that each double stranded DNA molecule replicates to form two new double stranded molecules - each with one original and one new strand. This occurs...
GC
Answered by Georgie C. • Biology tutor
2662 Views

Why is the oxygen saturation curve of haemoglobin sigmoidal?

The saturation curve of haemoglobin shows positive cooperativity. Initially, the porphyrin ring of the haem prosthetic group in haemoglobin is dome-shaped. When one molecule of oxygen binds one of the four s...
YM
Answered by Yunzila M. • Biology tutor
3507 Views