S.5 Bio B.O.T 2 2025 Expanded Guide

SSEMATIMBA GODFREY 1 0756341741 PROPOSED GUIDE MENTOR HIGH SCHOOL KITENDE PROPOSED GUIDE FOR BIOLOGY PAPER 1 EXPANDED GUIDE BEGINNING OF TERM 11 2025 Item 1. A pharmaceutical company has developed a new drug designed to target a specific protein embedded in the plasma membrane of cancer cells. However, during clinical trials, the drug appears to have reduced efficacy, which scientists suspect is due to changes in the membrane structure caused by elevated cholesterol levels in these cells. Using your understanding of the fluid mosaic model: a) Explain how elevated cholesterol levels might alter the structure and function of the plasma membrane. b) Discuss how these changes could affect the interaction between the drug and its target protein. c) Propose one modification to t he drug design or delivery strategy to overcome the observed issue, and justify your answer. SSEMATIMBA GODFREY 2 0756341741 PROPOSED GUIDE Item 2. A team of bioengineers is developing sy nthetic vesicles to mimic human cell membranes for targeted drug delivery. During testing, they notice that the vesicles are too rigid and do not allow for proper fusion with target cells, limiting their effectiveness. Using your knowledge of the fluid mo saic model of the plasma membrane: a) Explain the core principles of the fluid mosaic model and evaluate how this model helps us understand membrane behavior in living cells. b) Identify two specific components of a natural plasma membrane that the engineers should consider including or modifying in their synthetic vesicles. c) For each component identified in (b), analyze how it would improve the vesicle’s ability to mimic the structure and function of a natural membrane. a) The fluid mosaic model states that the plasma membrane consists of a phospholipid bilayer with embedded proteins, and both components can move laterally. This fluidity is vital for cell …