Carbohydrates

Properties of carbon atom

Properties of carbon atom

organic moleculse are large and complex

form cells of an organism and perform chemical reaction nescessary for life.

These molecules are called biomolecules are they are part of living matter and have carbon

The carbon molecules are held together by covalent bonds which is the strongest bond b/w atoms

individual carbon atoms can form up to four covalent bonds with other atoms to staify the outer shelll

In cells, there are majorly, hydrogen, carbon oxygen, nitrogen and more. CNOH have low atomic numbers and light elements are able to form strong bonds with other atoms to produce molecules

carbon atoms cn bind together in large number and thus creating chains

the carbon skleteon can be straight branched or cyclic.

typical organic molecule chains are very long, allowsing large no and variety of compounds

carbon atom bond together in different ways to yeild different molecules called isomeres.

they differ in bonding sequences which are called structural isomers

or they differe in spatial arrangements but their bonding sewuences are the same which are called steroisomers—> their phsycial and chemical properties may be drastically different,

Carbohydrates

• chemical compounds containing oxygen, hydrogen and carbon

• general formla —> CnH2On

• Hydroxyl groups

• simplest carbohydrate have aldehyde group called polyhydroxyaldehydes or keton group called polyhydroxyketones

• they can contain nitrogens, phosphates and sulpher compounds

• Carbohydrated+lipids =glycolipids

• carbohydrates+protiens=glycoprotiens

  • monosacchride, disaccharides, polysacchrides

Monosacchrides

Single sugar molecule

example: glucose

most oxygen atoms are in hydroxyl group and one part is carbonyl group , if sugar has aldehyde group means c is last in chain this is called aldose

in case that carbonyl group is in the midle and carbon atoms are on both sides, creating a keton grpup and sugar is ketose

GLucose: C6H12O6, hexose, form of sugar that fuels respiration

5 carbons on the corner and 6th corner taken by oxygen

galactose: hexose sugar, C6H12O6 but less sweet and found in milk

glucose and galactose only have a spatial difference

fructose: pentose sugar, found in fruits and honey

Ribose: pentose sugar pentagonal ring forms RNA

• highly soluble in living systems as solvent is water and sugar molecules have high number of hydroxyl group causing high stability and transportability

• carbohydrate molecules ecist n cyclic form , as they are lower in energy and themodynamically more stable than open chain counter parts

• carbohydrgrates provide yeild of eneryg and produce ATP molecules

Oligiosacchrides

Type of carbohydrate made up of 3-10 simple sugars

not abundant in diet, eg. stachyose

Small chain of monosacchrides attached by glycosidic bonds

Disaccharide

Two monosaccrides combine through condensation reaction, hydroxyl group of one monosaccrhide combines with hydrogen of another releasing molecule of water and creating covalent bond known as glycosidic linkage

Maltose: two glucose molecules together C12H22O11

lactose: glucose+galactose, C12H22O11 found in milk

Disaccharide: glucose+fructose —> C12H22O11 table sugar

Polysacchride

Long chain of monosacchrides linked by glycosidic bonds . chain can be unbranched and have differrent tpyes of monosacchrides

eg. starch, glycogen, cellulose and chitin

1-4 carbon link or 1-6 carbon linlk

They are beleived to be energy storage compounds

cellulose

Major component of plant cell way rigid structures that enclose the cells

made by linking together beta-glucose molecules

1-4 link

alternatively upways and downwards

straight chian

cellulose mlecules are unbranched chians of beta glucose, and the molecules are linked together by hydrogen bons.

they linked molecules created bundles caleld cellulose microfibrils

Cellulose prevents plant cells from bursting under very high pressure

do not branch

insoluble in dietary fiber made up of glucose polymers which are in plant cell walls.

Starch

forms of starch —> amylose and amylopectin

made by repeating glucose units

made by linking alpha glucose molecules

1- l4 link through condensation reaction

all glucose are molecules are oriented in same way leaidng ot a curve chain

Amylopection chain is branched leading to a gobular shape

Amylose is chain of alpha glucose, unbranched forming a helix

starch is made by plant cells —> amylose and amylopectin are hydrophilic but are too large to be solube in water,

doesn’t let too much water enter the cells thus not effectng the osmostic balance of cells

main storage of carbohydrates in plants

useful for glucose and energy, sstorage

it is a temperory store in leaf cells when glucose is being made faster by photosynthesis.

amylose do not branch

amylopectin branches every 20 subunits

glycogen

c6h10O5, made by repeating glucose subunits

branches many times, condensation reaction link carbon atoms through 1-4 linkage, alpha glucose, and branches occur when condensation when there is 1-6 linkage,

doesn’t effect osmotic balance, easy to + or - molecules to starch.

useful store for glucose, and an energy store

it is stored in liver and some muscle s for humans

large stores of dissolved glucose would cause osmotic problems.

branched every 10 subunits

Storage of carbohydrates in animals and fungi

Condensation reaction

Occurs between two unionized monomers like monosaccrides, hydrogen of one monomer+ hydroxyl group of another monomer release molecule of water.

removal of hydrogen from one monomer and removal of hydroxl group from another monoms allows the monomers to sharre electrons and thus creating a covalent bond.

the monomers are condensated together and creater a larger molecule which are called macromlecules.

prodcution of macromolecules by condensation reactions that link monomers to form a polymer

Hydrolysis reaction

Digestion of polymer into monomers

polymers are broken down into monomers is known as hydrolysis, in this water molecule is used during the breakdown. polymer is broken into two componenets, one part gains a hydrogen atom and the other gains a hydroxyl group from the hydrolisis

occurs when monosacchrides are released from complex carbohydrates through hydrolysis

Glycoprotiens —> cell- cell recognition

oligiosacchrides are attached to extracellular face of plasma membrane in form of glycoprotien, act as receptors for various signalling compounds

cell - cell recognition and adhesion

cell-cell recognition is the cells ability to distinguish one type of neighbouring cell from another. cell - cell recognition allows organization of tissues and can allows foreign cells or infected body cells to be identified or destroyed

example: antigens present on sruface of RBC are glycoprotiens providng ABO blood grouping

RBS;c have glycoprotiens in the plasma membrane that affects blood transfusion

Exxamples of oligiosacchrives are ABO, one or two of these glycoprotiens are present in every persons blood but never all three.

If blood containing glycoprotien A or B are transfused into a person who doesn’t produce the same themselves then the blood will be rejected, but that is not the case of O as it has same structure as A or B, with one less monosacchride thus it is not considered foreign

Antigens can be polysachrides, glycoprotiends or linked protiends