Carbohydrates: Classification and Properties

Monosaccharides & Disaccharides

________ are white crystalline substance; Starches are amorphous powder; cellulose is fibrous.

Molecular chirality

________ was discovered by Louis Pasteur back in 1848.

SER

________ (smooth endoplasmic reticulum) function is to synthesize carbohydrates.

Strands

________ in feces explains why cellulose are composed of fibers.

benzene rings

The ________ make the molecule stiffer, and form intermolecular cross- links analogous to hydrogen bonds.

Carbonyl

________ are seen in a "terminal position= "end.

word saccharide

The ________ "is derived from the Greek Saccharon, meaning "sugar.

(but too much carbohydrates

blood sugar may rise leading to diabetes)

Aldehyde present

"aldo"

Ketone present

"keto"

example

aldohexose

Solubility to ordinary solvents is inversely proportional to the complexity of their structures

Higher complexity lower solubility (inversely proportional)

Oxidation of monosaccharides

When the aldehyde function of an aldose is oxidized to a carboxylic acid the product is called an Aldonic acid

Lactose

Lactose is the sugar that's in milk

Maltose

consists of two molecules of glucose that are linked by an α-(1,4') glycosidic bond

forms of starch

amylose & amylopectin

homopolysaccharide

one saccharide unit

heteropolysaccharide

two or more saccharide units

amylose

linear, too long that forms helix

amylopectin

branched

Starch and Cellulose

monosaccharide & disaccharide are sweet; _________ are tasteless.

Sucrose

________- naturally occurring sugar found in various amounts in plants like fruits, vegetables and nuts.

Smooth Endoplasmic Reticulum

Its function is to synthesize carbohydrates.

Monosaccharides

________ do not usually exist in solution in their "open-chain" forms.

Fibers

Strands in feces explains why cellulose are composed of ______

Amylose

This chain is flexible enough to allow the molecules to twist into shape of a helix.

End

Terminal position

Chirality

________ is derived from the Greek word "kheir "that stands for "hand"

Solubility

________ to ordinary solvents is inversely proportional to the complexity of their structures. This means higher complexity, lower ________ (inversely proportional)

alcohol group

An ________ can add into the carbonyl group in the same molecule to form a pyranose ring containing a stable hemiacetal or hemiketal.

Carbon hydrates

Carbohydrates are also called what?

Polyhydroxy aldehyde or ketone

substances that yield such compounds on hydrolysis

Phenyl group (Ph)

A benzene ring with a single substituent is called a

Stereochemistry

the study of the three‐dimensional structure of molecules

L-glucose

cannot be recognized by our body because of the lack of enzymes

Chiral

any carbon atom which is connected to four different groups will be ______ and will have two non superimposable mirror images

Enantiomers

A chiral compound and its mirror image are referred to as _______

Glycogen

When carbohydrates serve as storage for chemical energy, the excess sugar will become in a form of _________

oxidation

In this process, ATP will be synthesized

Carbon

Carbohydrates are suppliers of _________ for the synthesis of cell components

Ketone

a functional group with the structure R₂C=O, where R can be a variety of carbon-containing substituents.

1:2:1

Molar composition of carbohydrates

Saccharon

Greek word which means sugar

Glucose

Found in cellulose

Enantiomers

these two have the same molecules but differ in its structure. Apparently, the difference in their formation creates a great effect with their function.

Chiral carbons

Also known as asymmetric carbon

Enantiomers

A chiral compound and its mirror image are referred to as

4 covalent bonds

In characteristic if carbohydrates, tetravalent means _______

Isomers

compound with same numbers of atoms each elements but in different formations by their bonds

2n rule

when the molecule has more than one chiral carbon, each carbon can possibly be arranged in either the right-hand or left-hand form, thus if there are n chiral carbons, there are 2n possible stereoisomers.

Fischer projection

Convenient way to represent mirror images in two dimension

If the hydroxy group points to right when the carbonyl is up

If the hydroxy group points to left when the carbonyl is up

Monosaccharides

simplest of the carbohydrates, since they contain only one polyhydroxy aldehyde or ketone

aldose

If the carbonyl group is at an end of the carbon chain (that is, in an aldehyde group), the monosaccharide is an

starch

amorphous powder

monosaccharides and disaccharides

white crystalline substance

reducing power

capacity to share electron

action of acids

not applicable to carbohydrates like monosaccharides because it is single unit (use of hydrochloric acid)

Phenylhydrazine

osazones are characteristic crystals resulting from the reaction of reducing sugars with _________

Aldonic acid

When the aldehyde function of an aldose is oxidized to a carboxylic acid the product is called an ______

Benedict's reagent

solution used in oxidation

pyranose ring

an alcohol group can add into the carbonyl group in the same molecule to form a __________ containing a stable hemiacetal or hemiketal

Pyranose ring

organic compound composed of 5 carbon and oxygen

piattos shape

Haworth projection

Ruminants

capable of digesting some of glucose units in cellulose. Most have a four-chambered stomach and two-toed feet.

Phosphate esters

sugar-phosphate backbone of DNA & RNA, ATP. They are linear ladder structure of DNA and RNA

Disaccharides

two monosaccharides linked together through a glycosidic linkage

Oligosaccharides

Contain two to ten monosaccharide units

O-glycosidic bond

chemical bonds holding monosaccharides together to form disaccharides

Starch

polymer consisting of glucose units

insoluble in water because of high molecular weight

Amylose

unbranched chains connected by (1-4) glycosidic linkages

10-20% in plants

This chain is flexible enough to allow the molecules to twist into shape of a helix

Amylopectin

consists of long chains of glucose connected by (1-4) glycosidic linkages, with (1-6) branches every 24 to 30 glucose units along the chain

80-90% of the starch in plants is in this form

Glycogen

- aka animal starch
- structurally similar to amylopectin, containing both (1-4) and (1-6) glycosidic linkages
- abundant in the liver and muscles
- it forms glucose on hydrolysis

Cellulose

- polymer consisting of long, unbranched chains of glucose connected by (1-4) glycosidic linkages
- most important structural polysaccharide; single most abundant organic compound on
- earth dietary fiber

Polysaccharides

don’t have free aldehyde or ketone group

Oxidation

cellular respiration on animal cells

Carbohydrates

is the central energy-yielding pathway in most non photosynthetic cells

Carbohydrates

primary role is to supply energy to all cells in the body