Write an essay on the structures, functions and movement of biological molecules. In your assignment you should start by comparing the structures of carbohydrates including glucose, starch and cellulose (1.1) Then go on to describe the plasma membrane. Discuss ways molecules move through the membrane including diffusion; osmosis; facilitated diffusion; and active transport (2.1). Relate how the phospholipid bilayer and membrane proteins affect the movement of molecules through the membrane (2.2). Next use the lock and key and induced fit hypotheses to explain how enzymes work (3.1). Explain how all the following factors affect the rate of enzyme-catalysed reactions: enzyme concentration, substrate concentration, temperature, pH and enzyme inhibitors (3.2). Finally, describe how disruption of an enzyme’s function can lead to health problems e.g. lactose intolerance (3.3)The essay should be approximately 1500 words (+/– 10%) In preparing your essay consider the following: 

• Your essay should be concise and written in a suitable scientific style. 
• Make good use of appropriate scientific terms
• Have an extensive reference list used selectively and appropriately within the text. 
• Have an introduction that sets the scene.
• Have a conclusion that summarises the main points covered.
• Each section or paragraph covering each point should be clearly referenced (i.e. in text citation). 
• All figures and tables used in your essay should be in the scientific format 
• The essay should demonstrate the ability to use the mechanics and conventions of written English including proper use of paragraphs. 
• As this is an essay, there should be no bullet points or subheadings. 

LO1: Explain properties of important biological molecules 1.1 Compare the structures of glucose, starch and celluloseLO2: Relate key structures in the plasma membrane to their functions 2.1 Describe the ways molecules move through the membrane to include: · diffusion · osmosis · facilitated diffusion · active transport 2.2 For the following components, relate how they affect movement of molecules through the membrane Phospholipid bilayer plasma proteinsLO3: explain the structure, function and significance of enzymes in the body. 3.1 use lock and key and induced fit hypotheses to explain how enzymes work. 3.2 explaine how all the following factors affect the rate of enzyme-catalysed reactions: · enzyme concentration · substrate concentration, · temperature, · pH and · enzyme inhibitors 3.3 Describe how disruption of an enzyme’s function can lead to health problems e.g. lactose intolerance
UK SOURCE(2018) Essential Cell biology(2013) Essential Cell BiologyBoyle & Senior – Collins Educational – 2008(2015) AQA A level Biology: Student Book 1(2015) AQA A level Biology Year 1 Student book(2015) Advanced Biology for you (2nd Edition), Nelson Thorne(20140) Ross & Wilson Anatomy and Physiology in Health & Illness (121st edition), Churchill Livingstonehttp://www.rsc.org/Education/Teachers/Resources/cfb/enzymes.htm http://highered.mheducation.com/sites/0072495855/student_view0/chapter2/animation__how_enzymes_work.html http://www.sumanasinc.com/webcontent/animations/content/enzymes/enzymes.html