BIOCHEM - Carbohydrates

carbohydrates

are poly-hydroxy carbonyl compounds (aldehyde or ketone) and their derivative and the polymer that give them on hydrolysis.

-OH groups

hydroxyl groups

aldehyde or ketone

carbonyl compounds

Monosaccharides

classification of carbohydrates that cannot be hydrolyzed into simpler carbohydrates

Disaccharides

condensation products of two monosaccharide units

ose

mono and di have this ending or suffix

saccharides

means sugars

Lactose

from Glucose and Galactose

sucrose

table sugar

sucrose

from Glucose and Fructose

Oligosaccharides

condensation products of three to ten monosaccharides

maltotriose

an example of oligosaccharide

glucose

an example of monosaccharide

lactose

an example of disaccharide

polysaccharides

condensation products of more than ten monosaccharide units

glycogen

an example of a polysaccharide that is stored in the liver for later energy use

Starch

an example of polysaccharide that is found in plants

aldehyde, aldose

the position or type of carbonyl group is in the terminal

ketone, ketose

the position or type of carbonyl group is in the middle

monosaccharides

simple sugar

monosaccharides

the simplest carbohydrates with 3-9 carbon atoms

aldose

a monosaccharide with an aldehyde group and many hydroxyl groups

ketose

a monosaccharide with a ketone group and many hydroxyl groups

glyceraldehyde

simplest aldose

dihydroxyacetone

simplest ketose

glucose

also known as dextrose

aldohexose

aldose term for glucose

glucose

the blood sugar

glucose

most abundant monosaccharide; found in fruits, vegetables, corn syrup, and honey

glucose

found in disaccharides such as sucrose, lactose, and maltose; makes up polysaccharides such as starch, cellulose, and glycogen.

cellulose

makes up paper and cotton

cellulose

cannot be digested since we don’t have the enzyme for it

70-110 mg/dL

normal blood glucose level

glycogen or fat

excess glucose is stored as …

insulin

is produced in the pancreas

insulin

regulates blood glucose levels by stimulating the uptake of glucose into tissues or the formation of glycogen.

hypoglycemic

low blood glucose; can easily faint

diabetes

a disease in which a person produces insufficient insulin to regulate blood sugar levels

fructose

sweetest carbohydrates; found in fruit juices and honey (fruit sugar)

fructose

it is converted to glucose in the bloodstream

glucose

fructose is converted into this when it enters the bloodstream

fructose

bonded to glucose in sucrose

ketohexose

ketose term for fructose

Galactose

Has a similar structure to glucose except for the –OH on Carbon 4.

Galactose

Cannot find in the free form in nature.

Galactose

Exist in the cellular membranes of the brain and nervous system.

Galactose

Combines with glucose in lactose (a disaccharide and a sugar in milk).

Galactosemia

a disease that is missing an enzyme that converts galactose to glucose

Galactosemia

accumulation of galactose in the blood and tissues which causes mental retardation and cataract

glyceraldehyde

has one chirality center, and has two possible enantiomers.

true

All carbohydrates have 1 or more chirality centers.

horizontal lines

in fischer projections, this represents bonds projecting forward from the stereocenter

vertical lines

in fischer projections, this represents bonds projecting to the rear.

chiral carbon

furthest from the carbonyl group

hemiacetals

this is formed when aldehydes and ketones react with alcohols

hemiacetals

contains a hydroxyl group (OH) and an alkoxy group (OR) on the same carbon.

cyclic hemiacetals

form readily when the hydroxyl and carbonyl groups are part of the same molecule.

L-glucose

artificial sweetener but expensive to make

at the bottom

when a fischer projection is twisted in 90degrees, all groups on the right will be …

alpha

Hydrogen is on top of the haworth structure

beta

OH is on top of the haworth structure

a-amylase

humans have this enzyme to digest starch products such as pasta

b-amylase

humans do not have this enzyme to digest starch or cellulose such as wood or paper

undigestible cellulose

helps in fiber, specifically in defecating and cleans our intestine

chair conformation

this structure has lines that go up and down simultaneously

mutarotation

Change in specific rotation that accompanies the equilibration of α and β anomers in aqueous solution.

physical properties of monosaccharides

colorless, sweet tasting, crystalline solids, polar w/ high melting points, soluble in water and insoluble in nonpolar solvents

its OH groups

monosaccharides are polar with high melting points because of …

H-bonds of OH groups

monosaccharides are soluble in water and insoluble in nonpolar solvents because of …

chemical properties of monosaccharides

formation of glycosides, oxidation, reduction

acetals

the formation of glycosides

anomers

two different stereoisomers

anomeric carbon

carbon that can have either the alpha anomer or beta anomer, depending on w/c side the hydroxyl attacks from

formation of glycosides

exist almost exclusively in cyclic hemiacetal forms; the process of reacting w/ an alcohol to give acetals

acetals

are formed when a carbonyl group reacts with an alcohol

acetals

are stable in water and bases but they are hydrolyzed in acids

oxidation of monosaccharides

Reducing sugars by another substance (i.e., benedict’s reagent)

benedict’s reagent

used to detect and reduce simple sugars

oxidized

the reducing agent; helps reduce the other reactant

reduced

the oxidizing agent; the one that is reduced

oxidation

loss of electron; process of losing an electron

reduction

gain of electron; process of gaining an electron

tautomerism

the rearrangement of atoms facilitated by an enzyme that forms isomers

copper

an example of benedict’s reagent

D-gluconic acid

produced right after the glucose reduced the copper

uronic acid

sugars w/ both carbonyl and carboxylic acid groups

reduction of monosaccharides

leads to the production of sugar alcohols

diarrhea and cataract

sugar alcohols that are not digested properly will likely cause…

reduction of monosaccharides

in the presence of H & Pd, the carbonyl will turn into alcohol, thus the double bond will be removed

alditol

contains an OH on every C

glucose meter or glucometer

device used to measure glucose levels

concentration of hydrogen peroxide (H2O2)

this gives you the glucose level

glucose oxidase

the enzyme that catalyzes the oxidation of glucose in the presence of oxygen

D-glucose

the carbohydrate utilized by the cell

disaccharides

consists of two monosaccharides linked by a glycosidic bond

glycosidic bond

the bond when one –OH group reacts with another –OH group

condensation reaction or dehydration

the process to form disaccharide, along w/ H2O

disaccharides

have at least one acetal carbon

acetal carbon

a carbon atom singly bonded to two OR (alkoxy) groups.

maltose

a disaccharide of two glucose molecules; Has a α -1,4-glycosidic bond (between two α-glucoses); and is a reducing sugar