Carbohydrates and Lipids Flashcards
Monosaccharides can be classified according to what?
Their number of carbon atoms
What are 2 important trioses?
Glyceraldehyde + dihydroxyacetone
What are 2 important pentoses?
Ribose + deoxyribose
What are 3 important hexoses?
Glucose, fructose, galactose
What is an isomer?
Chemical structures which contain the same atoms but are bonded together to form different 3D arrangements
What is monosaccharide cyclisation?
Longer-chain monosaccharides (such as pentoses and hexoses) form cyclic molecules
How are disaccharides formed and what are some important examples?
When two monosaccharides join together and eliminate water to form a glycosidic bond.
Sucrose, lactose, maltose
What are starches?
Polymers of glucose which serve as storage carbohydrates in plants
Describe amylose in terms of its percentage make up of starch, types of glucose chains, and types of bonds.
25%
Linear glucose chains
a-1,4 glycosidic bonds
Describe amylopectin in terms of its percentage make up of starch, types of glucose chains, and types of bonds.
75%
Branched glucose chains
a-1,4 and a-1,6 glycosidic bonds
What is cellulose and why is it important in human digestion?
A linear polymer of glucose. Cellulose is not digestible by humans and forms dietary fibre.
What is glycogen, and why is its structure advantageous to its function?
An extensively branched polymer of glucose obtained from animal sources. Its high level of branching means it has a large number of free ends, facilitating its rapid breakdown into glucose.
What is dextrin?
A branched oligomer of glucose that comes from the breakdown product of starch and glycogen
What are the 4 main types of biologically important lipids?
Fatty acids
Triglycerides
Cholesterol
Cholesterol esters
Describe the structure of fatty acids.
Hydrocarbon chains with a carboxyl group at one end and a methyl group at the other