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How is the concentration of sodium altered in a cell in the intestines and why is glucose absorption affected?

Imagine a cell like a rectangle, of which one side has finger-like projections (this side faces the intestinal lumen) called the villi, and the other side is flat - the base membrane of that cell that is. On...
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Answered by Antonis T. • Biology tutor
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Can you explain the process of DNA transcription?

The first stage of gene expression is DNA transcription. Transcription is the formation of single stranded mRNA from double stranded DNA. During transcription, the enzyme DNA helicase unwinds the double heli...
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Answered by Ashley M. • Biology tutor
4723 Views

Describe how hydrogen bonding arises in water

Water is made up of one oxygen and two hydrogen atoms. Oxygen is more electronegative than hydrogen, meaning the electrons in the hydrogen-oxygen bond are slightly more attracted to the oxygen. This makes th...
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Answered by Lucy T. • Biology tutor
6184 Views

What are the differences between glycogen, starch and cellulose?

All three of these are carbohydrate polymers, formed from glucose monomers. Glycogen and starch are both polymers of alpha glucose. These long chains of alpha glucose molecules, joined end-to-end, form a spi...
MJ
Answered by Matt J. • Biology tutor
45085 Views

What property of a mammalian nerve axon allows for fast saltatory conduction?

Myleination of the nerve axon by Schwann cells allows for fast saltatory conduciton, as the Schwann cells provide electrical insulation. Gaps between Schwann cells are known as Nodes of Ranvier, whereby elec...
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Answered by Hannah H. • Biology tutor
3267 Views