Biochemistry is a scientific discipline on the crossroad between chemistry and biology. This old branch of science has been transformed by the development of molecular biology and genetics which have connected the well-known biochemical pathways to the genes and macromolecules. Writing a good essay would inevitably involve a literature research in the recent peer-reviewed publications. Appropriate publication databases should be searched for relevant data, articles and reviews. Usual web search is unlikely to produce a comprehensive overview of existing body of knowledge since these days many scientific articles are simply not available in the free access.
Clear well-defined structure with logical and coherent flow of information is critically important. Your essay should tell a “story”, which would include basic well-established facts, recent findings (which might, on some occasions, contradict the existing dogmas), their interpretations and relevant scientific theories (either old or newly formulated), gaps in knowledge and potential future research directions needed to fill these gaps. Lots of new findings published these days challenge the existing views.
Reviewing up-to-date information would help to demonstrate not only your ability to learn the things taught at the classes but also to research and interpret new data. The latter is the most important skill for any independent researcher and something that, in the short terms, would bring you excellent marks.
Modern biochemistry relies on new analytic techniques which only became available in the recent decades and even years. These modern methods help to obtain structural information about complex molecules and their complexes, as well as analyse the chemistry of living cells on microscopic level. As a result, biochemistry uses analytical approaches of both organic chemistry (such as MNR, mass-spectrometry and various fluorescent methods) and biological sciences (such as macromolecular X-ray analysis, genetic analysis and others). Biochemical data inform scientists working in other fields such as medical research and biotechnology. All this means that proper literature research for your essay should focus on the most resent publications and reviews.
Research data and examples selected for essay should follow the logics of your essay. They should be not just relevant, but arranged in an order that helps to illustrate the right points at the right time. This would make the essay easily readable and understandable. Ability to communicate your thought clearly is always one of the points your essay will be marked for.
Obviously, the structure, depth and complexity of essay depend on the particular task at hands. The requirements for short undergraduate work and postgraduate dissertation are very different. But the major “selling” points mentioned above are always highly appreciated.