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What are some key components within the cell surface membrane, and what are their functions?

The cell surface membrane is formed of a phospholipid bilayer, in which the hydrophillic phosphate heads point outwards and the hydrophobic tails point inwards. This forms a barrier for large molecules such ...
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Answered by Maria K. • Biology tutor
3315 Views

How do I set out my introduction?

Due to the time limitation during your exam, it's important to make sure that your introduction is short, snappy and gets to the point right away. Generally, the basic structure of an exam introduction would...
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Answered by Kira B. • English tutor
2362 Views

Outline the difference between "positive" and "negative" freedom?

The distinction between positive and negative notions of freedom can be traced to Isaiah Berlin and his 1936 essay: "Two Concepts of Liberty". Negative freedom is defined as freedom from obstacles,...
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Answered by Rooban S. • Politics tutor
18815 Views

What is an immobilised enzyme and what are the advantages of their use?

Immobilised enzymes are enzymes that have been trapped into an inert matrix or material (such as calcium alginate) which prevents them from moving during the reaction process. Whole cells such as yeast and b...
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Answered by Rooban S. • Biology tutor
43639 Views

Why is there more than one solution to x^2 = 4?

Think about it as 'What numbers can be x to get 4'. Remember that when you square a number the answer is always positive? Here is a situation in which it's important to consider both of the possible solution...
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Answered by Benjamin T. • Maths tutor
4249 Views