1. Test review Any annotations have to be in a different colour!

2. Reading outside the classroom
For each topic you are expected to read in your own time.
Minimum expectation is to read the recent chapter in the textbook.
On the day of the end of topic test you have to hand in your notes on the topic:
Essay
Bullet points
Mind map/ spider diagram/ concept map

3. Carbohydrates

4. Bell Ringer: Organic molecules
What is a macromolecule?

5. Bell ringer – organic molecules
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Chemistry crash course:
Bozeman Science –
The Molecules of Life

6. What are Carbohydrates?
Organic compounds which comprise of only C, H and O
Carbo-Hydr-ate
C H O

7. Types of Carbohydrate
Monosaccharides
Disaccharides
Polysaccharides

8. Monosaccharides Simplest – ‘Single sugars’ Same no. of C as O atoms
e.g. Glucose is C6H12O6
Have the general formula (CH2O)n
Where n is any number between 3 and 7
White crystalline solids
Dissolve in water to form sweet tasting solutions

9. The structure of glucose
You only need to be able to draw α-glucose in its simplified form….

10. The structure of glucose
α-glucose and β-glucose are ISOMERS
(compounds with the same formula but a different arrangement of atoms)

11. Monosaccharides form Disaccharides in condensation reactions+
Maltose
H2O

12. Monosaccharides form Disaccharides
The bond formed is a glycosidic bond
A condensation reaction occurs to join the 2 monosaccharides
α 1-4 glycosidic bonds

13. Disaccharides hydrolyse to form Monosaccharides
H2O

14. Disaccharides form Polysaccharides
Starch

15. Starch
The α-helical structure of starch makes it good for storage (it’s compact!)
Starch is insoluble due to its structure
It is therefore the main plant storage sugar

16. Cellulose Polymer of β-glucose Each monomer is inverted.
Has consequences for
its properties

17. Cellulose
Forms chains which run parallel with hydrogen bonds between the chains to form microfibrils
Microfibrils are strong
Being fibrous, cellulose is structurally important in plant cell walls

20. Glucose is not the only monosaccharide...
Fructose:
Glucose and fructose
combine to form sucrose
(a disaccharide)

21. Glucose is not the only monosaccharide...
Galactose
Glucose
Galactose
Glucose and galactose combine to form Lactose

22. Summary α-glucose + α-glucose = maltose
The polymer of α-glucose is starch
The polymer of β-glucose is cellulose
Glucose + fructose = sucrose
Glucose + galactose = lactose

23. You should be able to draw examples of carbohydrates from memory!
– practise using look-cover-write-check
Task
Use the molymods to build the following molecules: α-glucose, β-glucose, fructose and carry out a condensation and a hydrolysis reaction.
Use the molymods and the textbook to complete the worksheets on carbohydrates
Challenge
Use the structure of α- and β–glucose to explain the difference in structure between cellulose and starch

24. Check your work

25. HW: ESSAY
Compare the structure and function of a cellulose molecule and starch. [7]