L1 Carbohydrates metabolism and glycobiology

Question 1

Production of carbohydrates

Answer 1

photosynthesis is the main

Question 2

Glucose

Answer 2

Energy stores, direct fuels

Question 3

Sugars

Answer 3

Backbones (DNA,RNA), and structural roles, strength of bacterial cells like peptidoglycan

Fungi - polysaccarides e.g chitin provides cell strength.

Modified sugars - cellulose forming lignin.

Question 4

Characteristics of carbs

Answer 4

(CH2O)n
contain at least 2 hydroxyl groups and carbonyl groups.
Different types
Aldose, Ketose
some contain nitrogen,phosphorus and sulfur.

Hydrophilic, very soluble.

Can polymerize

Question 5

Classification of sugars

Answer 5

Monosaccarides - Ketose and Aldose
d or l isomerism (chirality)

Chiral (same components, different arrangement)
Enantiomer - mirror images
Diastereo - non mirror image
Epimer - differ only in 1 stereogenic center

Question 6

Fructose

Answer 6

Can form 5 or 6 membered rings (pyran and furan)

Question 7

Pyranose (6) ring formations

Answer 7

Reduced bond freedom.
Chair or boat form.
Chair is favoured as bonds are spaced out.

Question 8

Reducing and non reducing sugars

Answer 8

Ring forms are non-reactive but their linear form will react.

Question 9

Glycosidic bonds

Answer 9

Synthesis of glycoproteins.

Mehtylation of sugars

Question 10

Phosphorylation of sugar

Answer 10

If its ringed (phosphorylated), the molecule is less stable, so enzymes can act upon the sugar. It makes it less peromeable to cell membrane, requiring an active transport system.