Carbohydrates

Question 1

Carbohydrates

Answer 1

Most common organic molecules, contain C, H, and O in 1:2:1 ratio

Question 2

Functions

Answer 2

Source of energy, building material, cell surface markers (for id and communication)

Question 3

Monosaccharides

Answer 3

Simple sugars consisting of one sugar unit –> straight C chains or rings with OH groups, distinguished by # of C and type of carbonyl group (ex, glucose, galactose, fructose)
- Polar due to high proportion of hydroxyl and carbonyl groups (dissolves easily)

Question 4

Monosaccharides: Structural Isomers

Answer 4

Molecules that contain same same molecular formula but different spatial arrangements, resulting in different properties –> ex. glucose vs galactose

Question 5

Monosaccharides: Stereoisomers

Answer 5

Molecules with same structures, but one group is rotated differently, resulting in different molecule connections (ex. beta glycosidic linkages where beta glucose must alternate orientation)

Question 6

Disaccharides (Ogliosaccharides)

Answer 6

Two simple sugars bonded together
–> 1-4 glycosidic linkages (condensation between two hydroxyl groups)

Question 7

Common Disaccharides

Answer 7

Maltose = a-glucose + a- glucose
Lactose = a-glucose + a-galactose
Sucrose = a-glucose + a-fructose

Question 8

Polysaccharides

Answer 8

Complex carbs - long chains of monosaccharides (have low solubility due to length)

Question 9

Storage Polysaccharides

Answer 9

Starch and Glycogen - made up of a-glucose molecules

Question 10

Starch

Answer 10

Main storage molecule in plants
(ex. potato starch: combo of amylose in straight chains & branched amylopectin –> animals use enzymes like amylase to breakdown into individual molecules)

Question 11

Glycogen

Answer 11

Storage molecule in animals used to store excess glucose –> like amylopectin but more branched
- Small amounts stored in liver and muscle (used for energy during bouts of physical activity)

Question 12

Structural Polysaccharides

Answer 12

Cellulose and Chitin - made up of b-glucose molecules

Question 13

Cellulose

Answer 13

Primary structural polysaccharide in plants (component of cell walls)
- Beta 1-4 glycosidic linkages (zig zag pattern) resistant to starch breaking enzymes
- But causes roughage: passes through undigested and scrapes large intestine causing mucus production which lubricates feces

Question 14

Chitin

Answer 14

Found in hard exoskeleton of insects & crustaceans, and cell walls of fungi
–> composed of modified cellulose material (nitrogen in group at 2’ carbon of b-glucose)