“Plagiarism is defined as submitting as one's own work, irrespective of intent to deceive, that which derives in part or in its entirety from the work of others without due acknowledgement. It is both poor scholarship and a breach of academic integrity.”
Although there is no assessed course work for Biochemistry and Molecular Biology it is an essential part of your scientific training that, in your supervision work and any other writings, you ensure you are following best practice regarding avoiding plagiarism.
General university guidelines are available
Faculty guidelines are also available
Note that the use of essays purchased from any source or copied from other students is unacceptable regardless of whether the source is acknowledged.
It is an important aspect of academic integrity to cite all sources on which you base your work (even if it is not copied directly from them), be they published in hard copy or web based. Your supervisor may ask you to do this for written work produced during the year, and this can be useful for your subsequent revision. However, full citation is not expected in written unseen examinations such as those taken at the end of the year for BMB.
If you still have questions, you should talk to your Supervisors and /or Director of Studies and/or the Course Organiser.