[2.5] CARBOHYDRATES (POLYSACCHARIDES)

POLYSACCHARIDES

More than 10 sugar units (can reach up to thousands)

Homopolysaccharide

Only one type of sugar

Heteropolysaccharide

2+ types of monosaccharides

Starch

Storage polysaccharide of plants.

Starch

"storage product of photosynthesis"

amyloplast:

starch storage

chloroplastin

- green

chromoplastin

- other colors

leukoplastin

- colorless

elaioplastin

- oil storage

proteinoplastin / aleuroplastin

- protein storage

Glycogen

storage form of glucose in animals

Glycogen

found in liver and muscle

Chitin

fungal cell wall

Chitin

commercial source:

crustaceans (crabs, shrimps)

Chitin

chemical component:

N-acetylglucosamine (NAG) (an amino sugar)

Cellulose

plant cell wall

What plant cell part/structure is being reinforced/strengthened by cellulose?

Cell wall (structural component of plant cell walls)

STARCH

structure

Polymer of glucose (pyranose) linked by

α(1->4) and α(1->6) glycosidic bonds

Adding iodine to a starch sample under a microscope

improves visibility by staining the starch granules

STARCH

sources can be differentiated by

microscopic analysis (type of evaluation: microscopic evaluation)

STARCH

sources

mature grain of corn

mature grain of wheat

tubers of potato

rice

Zea mays

Mature grain of corn or maize

Zea mays

rectangular or hexagonal

hilum: distinct feature at the center

Triticum aestivum

Mature grain of wheat

Triticum aestivum

oval, elongated, circle

no sharp edge

single or cluster; usually single

Solanum tuberosum

Tubers of potato

Oryza sativa

Rice

Amylose

Traditional Old Name

(β-amylose)

Amylose

Structure

Linear or unbranched

Amylose

Units

250-300 units

Amylose

Linked by

α(1→4) only

Amylose

H2O

Solubility

More soluble

Amylose

Iodine Test

Deep blue

Iodo-Starch Complex

Amylose

Abundance

25%

Amylopectin

Traditional Old Name

(α-amylose)

Amylopectin

Structure

Branched

Amylopectin

Units

1000/more glu units

Amylopectin

H2O

Solubility

Less soluble

(paste-forming property of starch, gawgaw in tagalog)

Amylopectin

Linked by

α(1→4) with α(1→6) every 25 glu units

Amylopectin

Iodine Test

Blue Violet/Purple

Iodo-Starch Complex

Amylopectin

Abundance

75%

Amylase

Enzymes that break down starch

Two kinds of amylase:

α-amylases

β-amylases

α-amylases

enzyme in

-Pancreatic Juice (Amylopsin)

-Saliva (Ptyalin)

α-amylases is capable of __ (target location)

Random splitting of α-1,4 links

α-amylases

end product

Mixture of

-Glucose

-Maltose

-Amylopectin

β-amylases are capable of __

splitting α-1,4 bonds

β-amylases target location

At branching points:

-Maltose & Dextrins (incomplete hydrolysis)

Limiting dextrins (oligosaccharide)

causes browning of bread

β-amylases

End-product:

Nearly pure maltose (complete hydrolysis)

STARCH BIOSYNTHESIS

starts at the cytosol, the liquid part of the plant cell (glucoses are not formed inside the chloroplast, but in the cytosol)

Glucose must be either in the

phosphorylated form or UDP-Glucose form

G6P → G1P

by phosphoglucomutase

G1P → ADP-Glucose

by ADP-glucose phosphorylase

Once you have ADP-Glucose,

starch elongation starts

Add glucose to the nonreducing end by ___ for elongation

starch synthase

For the addition of branches in amylopectin, __ is used found in the amyloplasts

branching enzyme

starch

uses

-Tablet filler, binder, and disintegrant (releasing active constituents)

-Antidote for iodine poisoning (forms iodo-starch complex)

Modified Starches

Pregelatinized starch

Sodium Starch Glycolate

Hetastarch (hydroxyethyl starch)

Pregelatinized starch:

starch that is chemically or mechanically processed to rupture all or part of the granules; tablet binder

Sodium Starch Glycolate:

disintegrating agent

Hetastarch (hydroxyethyl starch):

-plasma expander at 6%

-NOT a substitute

Expander

to return the volume of blood levels due to heavy bleeding from an injury

GLYCOGEN

description

-Branched homoglycan (polymer of glucose), resembling amylopectin

-α(1 → 4) and α(1 → 6) glycosidic bonds (more branched than starch, branching every 8th to 12th)

GLYCOGEN

synonym

"Animal starch"

GLYCOGEN

test

IODINE TEST: Wine red

INULIN

is rich in plants under

asteraceae family

INULIN

description

Fructan linked by β(2 → 1) with one molecule of glucose at the terminal end (Major monosaccharide present: Fructose)

Rich in plants under the Asteraceae family

INULIN

Use

Used for evaluation of renal function (most accurate but not anymore used clinically)

other fructans

phleins

agropyrene

sinistrin

DEXTRAN

description

Glucan linked by α(1 → 6) bonds with some branching due to α(1→3)

DEXTRAN is from

Leuconostoc mesenteroides

By dextran sucrase or transglycosylase which is responsible for the conversion of sucrose to dextran

DEXTRAN use

Plasma expander at 10% (due to osmolality and viscosity similar to plasma)

DEXTRAN use

Given to patients with hypovolemia

hypovolemia

a condition that occurs when your body loses fluid, like blood or water

DEXTRAN use (iron dextran)

IV Iron supplement (used when oral iron is not tolerated; toxic to git)

CELLULOSE

description

Polymer of glucose linked by β(1→4) glycosidic bonds

CELLULOSE

Not digested by mammalian enzyme systems, due to

their lack of cellulase (no capacity to break down beta glycosidic bonds)

Bacteria, rumen microflora, or herbivores animals

have cellulase

CELLULOSE

description

Component of cell wall (responsible for its rigidity)

Most abundant organic compound on earth

CELLULOSE

use

Mechanical protection against bacteria

Absorbs mucus, pus, and blood

Cotton

Purified / Absorbent cotton source

- from the hair of the seeds of Gossypium hirsutum or G. herbaceum

Cotton

description

-cylindrical when young, flattened and twisted when it matures

-Waxy cuticle renders it nonabsorbent

Bleached cotton yarn and absorbent cotton wool

- wetted by water

Cellobiose

= 2 glucose units

Cotton

test

Ammoniacal CuO

cotton

test: ammoniacal CuO (raw cotton)

dissolves, leaving fragments of cuticle

cotton

test: ammoniacal CuO (absorbent cotton)

dissolves with uniform swelling

Cellulose: Regenerated Fibers

source

Chemically modified fibers

From the cellulose of Coniferous plants

Cellulose: Regenerated Fibers

produced from

naturally occuring, long-chain molecules which have been isolated, controlled, and modifies to give a suitable fibre form

Cellulose: Regenerated Fibers

use Viscose (Rayon) -

used for surgical dressings

Cellulose: Regenerated Fibers

use Continuous filament rayon:

used for blouse fabrics

Cellulose: Regenerated Fibers

use Staple rayon:

cut up of fixed length; used in surgical dressings

Methylcellulose

Prepared by the action of methyl chloride on alkali cellulose

Methylcellulose

Best grade when 2 out 3 OH in glucose are methylated (Requirement for methylcellulose)

Methylcellulose

use

Lotions

Suspensions

Pastes

Laxative

Curbing appetite

Carmellose (carboxymethyl cellulose )

By the action of monochloroacetic acid on alkali cellulose

Carmellose (carboxymethyl cellulose )

use

Lotions

Suspensions

Pastes

Laxative

Curbing appetite

Ethylcellulose

use

Tablet binder

Film coat