Wallington County Grammar School

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1 Wallington County Grammar School Y11 to Lower Sixth Bridging Work Subject: Subject Leader to direct questions to ( Estimated hours of work needed to complete this work successfully: This work is entirely relevant to the Course Specification. It will help prepare you for your A Level in this subject because: This work will be given an effort grade from 1-4 (4 being highest) that will be sent home and used to inform our intervention. In order to get a 4 you must ensure you: Biology Mrs Burgess 4 In September the topics you will start to learn about are Cells and Biological Molecules. By completing the bridging work, you will have already defined the key words used in the Biological Molecules section of the course and started looking at the key concepts that you will be taught in lessons for the first half term. Complete the work with as much detail as possible and ensure that you have completed the extension work. Your Bridging Work 1

2 BIOLOGY DEPARTMENT BRIDGING UNIT This project contains compulsory work that must be completed before term starts in September. You will prepare for the new challenges of Sixth Form study by researching some key content and gaining an understanding of important Biological principles. You will complete 6 tasks, and attempt an extension task, that will provide information to help with the first topic on the A Level Biology course called Biological molecules. Specification for reference: BIOLOGICAL MOLECULES Unit description All life on Earth shares a common chemistry. This provides indirect evidence for evolution. Despite their great variety, the cells of all living organisms contain only a few groups of carbon based compounds that interact in similar ways. Carbohydrates are commonly used by cells as respiratory substrates. They also form structural components in plasma membranes and cell walls. 2

3 Lipids have many uses, including the bilayer of plasma membranes, certain hormones and as respiratory substrates. Proteins form many cell structures. They are also important as enzymes, chemical messengers and components of the blood. Nucleic acids carry the genetic code for the production of proteins. The genetic code is common to viruses and to all living organisms, providing evidence for evolution. The most common component of cells is water; hence our search for life elsewhere in the universe involves a search for liquid water. By the end of the bridging work you will be expected to be able to: Explain what a monomer and polymer are Identify some biological polymers, and the monomer from which they are made Describe the stages of the Benedict s test Describe the stages of the Iodine test Describe the stages of the emulsion test Identify common monosaccharides Describe the monosaccharides from which lactose, maltose and sucrose are made Explain what is meant by a glyosidic bond and how they form through condensation 3

4 1. Define the following key terms related to Biological molecules Activation energy Amino acids Base pairing Carbohydrate Chromatography Colorimetry Condensation Denaturation Dipeptide Disaccharide DNA Enzyme Fatty acid Fibrous protein Hydrolysis Globular protein Glycerol Hydrogen bonding Inhibition Inorganic ion Isomer Lipid Macromolecule 4

5 Monomer Nucleic acid Phospholipid polymer Polypeptide Polysaccharide Primary structure Protein Quaternary structure RNA Secondary structure Tertiary structure Triglyceride Water 5

6 2. Describe the following tests for Biological molecules: Benedict s test Method: Positive result: Biuret test Method: Positive result: Lipid emulsion test Method: Positive result: 6

7 3. Draw the structure of the following: a) α Glucose b) β glucose c) Describe the differences between the structure of α and β glucose.. d) Are these structures triose, pentose or hexose sugars?. e) Draw the general structure for an amino acid: 7

8 4. State the name or names of the monomers related to the polymer: Polymer DNA Monomer (s) Maltose Starch Glycogen Sucrose Lactose Protein 8

9 5. Complete the following information about carbohydrates by filling in the gaps: Carbon atoms are able to bond with other carbon atoms. These form a backbone along which other atoms can be attached. This permits the formation of a great number of types and sizes of molecule, all based on carbon. The variety of life that exists on earth is a consequence of all living organisms being based on carbon. Carbon-containing molecules are known as organic molecules. In living organisms, there are relatively few other atoms that attach to carbon. Life is therefore based on a small number of chemical elements. In the Biology course you will study the following Biological molecules; Carbohydrates, proteins, lipids, water and nucleic acids. Carbohydrates are made up of sugar units and have the general formula. are the simplest carbohydrates, with only one sugar unit. Examples are, fructose and galactose. Two monosaccharides join together to form a in a reaction. Two hydroxyl (OH) groups react a molecule is lost, and the remaining oxygen atom joins the two sugar units together. This is called a. The bond can be broken in a reaction, which is a reverse of the condensation reaction. The position of the OH groups that react determines the, and therefore properties of the disaccharide. A series of condensation reactions between monosaccharides can create a molecule its features will depend on the sugar monomers from which it is formed. Starch is formed from two polymers: and. The former has 1,4 glycosidic links and forms helices, whilst the latter has many 1,6 glycosidic links, which cause the chain to branch. Starch is a good energy storage molecule because it is, insoluble and does not take part in reactions in the cell. 9

10 Glycogen is also formed from chains of. It is found in animal livers, where it acts as an intermediate energy store. It contains 1,4 and 1,6 glycosidic links, so it is more than starch. molecules lie straight and form with their neighbours. Bundles of these cross-linked molecules form strong visible in the plant cell wall. 10

11 6. Construct a mind map for Monomers and polymers. Use as many of the key terms from task 1 as you can/are relevant. This has been started for you below: Polymer Glucose Monomers and polymers Monomer Starch Amino acid 11

12 7. EXTENSION ACTIVITIES 1. Complete the table: Monosaccharide Glyceraldehyde Ribose Deoxyribose Fructose Glucose Number of carbon atoms per molecule Where is it found in living organisms 2. Glucose and fructose have the same general formula; can you explain why they are distinct monosaccharides? 3. Name the elements present in carbohydrates. 4. Write down the molecular formula of a triose. 5. Suggest how many carbon atoms are present in a pentose. 12

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14 7.EXTENSION 14

15 7. EXTENSION 15