f) g) Starch, Glycogen, Cellulose

Starch is in plants and made up of what?

Amylose

Amylopectin

Amylose structure

- Unbranched and helix shaped (coiled)

- Only 1,4 α-glycosidic bonds

How does the coiled shape of amylose help?

Enables it to be more compact

Amylopectin structure

- Branched and uncoiled

- Has 1,4 and 1,6 α-glycosidic bonds

Why is the branched structure of amylopectin?

The branches mean many glucose molecules can be easily hydrolysed for use during cellular aerobic respiration

Glycogen is in animals and is made up of what?

Alpha glucose subunits

Glycogen structure

- Branched molecule

- Has 1,4 and 1,6 α-glycosidic bonds

Do starch and glycogen dissolve?

No, therefore they don't affect the water potential.

Cellulose structure

- Unbranched

- 1,4 β-glycosidic bonds, that must be rotated 180° to each other

Beta glucose glycosidic bonds

They form beta pleated sheets between hydrogen bonds, which can form cross links to form bundles called microfibrils.

Larger microfibrils are called....

macrofibrils

Importance of cellulose structure:

Provides high tensile strength and make up plant cell walls.

Allows water to pass through, preventing the cell from bursting, determining shape.