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Biology

A Level

Describe the different levels of protein structure during the production of a protein

Primary Structure: Peptide bonds form between the carboxyl and amino groups of adjacent amino acids, forming a long polypeptide chain.

Answered by Grace T. • Biology tutor

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A bacterial infection that cannot be treated with one sort of penicillin can be treated with a different sort. Use your knowledge of enzyme action to explain why the different sort of penicillin is effective in treating the infection.

Penicillin inhibits an enzyme that forms cross links in bacterial cell walls halting bacterial reproduction. Different penicillins have different shapes or structures. The penicillin that is not effective...

Answered by Georgia D. • Biology tutor

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Explain how the intensive rearing of domestic livestock increases net productivity

Productive animals are selectively bred to ensure the next offspring will be equally, if not more productive. These young animals are kept inside in warm conditions to limit energy loss due to maintaining...

Answered by James A. • Biology tutor

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Nitrate from fertiliser applied to crops may enter ponds and lakes. Explain how nitrate may cause the death of fish in fresh water.

The applied nitrates may seep into water sources from the fields at times of rainfall. Here, they increase the nitrate concentration in the water, leading to an algal bloom. This layer of surface algae bl...

Answered by James A. • Biology tutor

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