Download presentation
Presentation is loading. Please wait.
Published bySharyl Harper Modified over 9 years ago
1
Bodies main energy source CH 2 O Only plants synthesise carbohydrates Starch, Cellulose (polysaccharides) Lactose, sucrose (dissaccharides) Glucose, fructose (monosaccharides) CARBOHYDRATES
2
(CH 2 O) n where n=3 to 9 Aldehydes or ketones containing a carbonyl group and at least 2 hydroxyl groups Hexoses (glucose, galactose, fructose) MONOSACCHARIDES
3
Contain 5 carbon atoms Ribose PENTOSES
4
Low molar masses Sweet Soluble in water Crystalline solids Reducing sugars (aldehyde group oxidised) PROPERTIES OF MONO AND DI-SACCHARIDES
5
STRUCTURE OF GLUCOSE
6
INTERCONVERSION OF Α AND Β GLUCOSE
7
STRAIGHT CHAIN AND CYCLIC FRUCTOSE
8
CONDENSATION OF MONOSACCHARIDES
9
DISACCHARIDE FORMATION Β-glucose + β-galactose -----> lactose α-glucose + α-glucose -------> maltose α-glucose + β-fructose ------> sucrose
10
Numerous monosaccharide units Large masses Not sweet, non-reducing, insoluble Starch is plant store for glucose Two forms : Amylose (water soluble) Amylopectin (water insoluble) POLYSACCHARIDES
11
α-1,4 glycosidic linkages AMYLOSE
12
α-1,4 glycosidic linkages as well as α-1,6 glycosidic linkages AMYLOPECTIN
13
More highly branched than amylopectin but also has α-1,4 glycosidic linkages as well as α-1,6 glycosidic linkages GLYCOGEN
14
Linear Made up of β-glucose units with all glycosidic linkages in the 1, 4-position Extensive hydrogen bonding between chains Strength, rigidity Insoluble CELLULOSE
15
MAJOR FUNCTIONS OF CARBOHYDRATES Energy Source Energy Reserve (e.g. glycogen) Precursor of other Biologically Important Molecules (e.g. anticoagulants, components of nucleic acids)
16
DIETARY FIBRE Plant material Cannot be digested by humans Parts of fruits, vegetables, grains May be digested by bacteria in gut Cellulose Lignin Pectin
17
IMPORTANCE OF HIGH FIBRE DIET Constipation and Diverticulosis Irritable bowel syndrome Obesity Crohn´s Disease Haemorrhoids
18
READING AND QUESTIONS Please read pages 331 to 334, all about carbohydrates. Take your own notes. Make a mind map. Can you answer the questions in the orange boxes (B.3.1 etc) ? Now answer questions 9 to 16 on page 359.
Similar presentations
© 2024 SlidePlayer.com. Inc.
All rights reserved.