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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
38518 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
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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
2726 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
3580 Views

What is the benefit of myelination of an axon?

Myelination of an axon makes propagation of action potentials along it much faster. In unmyelinated axons, the action potential is constantly regenerated by active propagation, with the depolarisation causin...
YM
Answered by Yunzila M. • Biology tutor
3772 Views