2.3: Carbohydrates and lipids

prior learning & retrieval practice

Essential idea: Compounds of carbon, hydrogen and oxygen are used to supply and store energy.

S2: Determination of body mass index by calculation or use of a nomogram.

Exercise 1: Determine your BMI using the nomogram below, then calculate it using the forumla. BMI = M/H squared

S1: Use of molecular visualization software to compare cellulose, starch and glycogen.

Exercise 1:  Use the visualisation software linked to below to describe the structure of each of the above polysaccharides and to compare them.

A1: Structure and function of cellulose and starch in plants and glycogen in humans.

Exercise 2: State the function of each of these carbohydrates. How does their structure as described in your notes relate to their function? You can also use the pdf below for further information.

U1: Monosaccharide monomers are linked together by condensation reactions to form disaccharides and polysaccharide polymers.

Exercise 3: Describe how the following disaccharides are made and what their functions are: Sucrose, lactose and maltose. Compare and contrast the monosaccharides that make them.

Guidance from the syllabus: The structure of starch should include amylose and amylopectin. Sucrose, lactose and maltose should be included as examples of disaccharides produced by combining monosaccharides.

U2: Fatty acids can be saturated, monounsaturated or polyunsaturated. 

Exercise 4: Draw the structure of each of the above fatty acids. Compare and contrast them.

Guidance from the syllabus: Named examples of fatty acids are not required.

U3: Unsaturated fatty acids can be cis or trans isomers.

Exercise 5: Draw the structure of cis and trans isomers. (Could potentially make timelapse videos using molymods or screencasting software.)

U4: Triglycerides are formed by condensation from three fatty acids and one glycerol.

Exercise 6: Draw the formation of triglycerides.

A3: Lipids are more suitable for long-term energy storage in humans than carbohydrates.

Exercise 7: Compare and contrast the functions of carbohydrates and lipids.

A2: Scientific evidence for health risks of trans fats and saturated fatty acids.

Exercise 8: Outline the scientific evidence for health risks of trans-fats and saturated fats

NoS: Evaluating claims—health claims made about lipids in diets need to be assessed. (5.2)

A4: Evaluation of evidence and the methods used to obtain the evidence for health claims made about lipids.

Exercise 9: Evaluate the evidence and the methods used to obtain the evidence for health claims made about lipids.