Chapter 9 - Carbohydrates (Bishops)

Organism rely on the oxidation of complex organic compounds to obtain energy.

True

Three general types of complex organic compounds to obtain energy

1. Carbohydrates

2. Amino acids

3. Lipids

The primary source of energy for brain, erythrocytes, and retinal cells in humans.

Carbohydrates

The major food source and energy supply for the body and are stored primarily in the liver and muscle as GLYCOGEN.

Carbohydrates

The two split into a disease related to carbohydrates.

1. Hyperglycemia

2. Hypoglycemia

A compound containing C, H, O

Carbohydrates

Disease states involving carbohydrates are split into two groups?

hyperglycemia (which can lead to diabetes mellitus)

and hypoglycemia.

are compounds containing C, H, and O.

Carbohydrates

The general formula for a carbohydrate is

Cx(H2O)y

All carbohydrates contain _____ and _______ functional groups.

C=O and –OH functional groups.

The classification of carbohydrates is based on four structural properties:

(1) the size of the base carbon chain,

(2) the location of the CO function group,

(3) the number of sugar units,

and (4) the stereochemistry of the compound.

based on the number of carbons in the molecule. For example, trioses contain how many carbons?

three carbons

tetroses contain

four carbons

pentoses

5 carbons

hexoses

6 carbon

In actual practice, the smallest carbohydrate is

Glyceraldehyde - a three carbon compound.

What are the hydrates derivate of carbohydrates?

Aldehyde and Ketone derivatives based on the location of the CO FUNCTIONAL GROUP.

The two forms of carbohydrates

1. Aldose

2. Ketose

has a terminal carbonyl group (O=CH–) called an aldehyde group

Aldose form

has a carbonyl group (O=C) in the middle linked to two other

carbon atoms (called a ketone group).

Ketose Form.

Ketone

Aldehyde

It has the aldehyde or ketone at the top of the drawing.

The compound can be represented as a straight chain or might be linked to show a representation of the cyclic, hemiacetal form.

The Fisher projection

represents the compound in the cyclic form that is more representative of

the actual structure. This structure is formed when the functional (carbonyl) group (ketone or aldehyde) reacts with an alcohol group on the same sugar to form a ring called either a hemiketal or a hemiacetal ring,

Haworth projection

four different groups areattached to the carbon atoms.

Asymmetric (chiral)

This allows for various spatial arrangements around each

asymmetric carbon (also called stereogenic centers) forming molecules called

Stereoisomers.

have the same order and types of bonds but different spatial arrangements and different properties

Stereoisomers

A monosaccharide is assigned to the D or the L series according to the configuration at the highest numbered asymmetric carbon.

In a Fischer projection, the OH group on the configurational carbon is on the left. Which series is the sugar in?

L - Series

A sugar has 3 chiral carbons. What is the maximum number of stereoisomers?

8

What is the relationship between D-glyceraldehyde and L-glyceraldehyde?

Most naturally occurring sugars in humans are

in the d-form or l-form?

D - Form.

When they split, one molecule of water is consumed to form the individual

sugar compounds. This reaction is called

Hydrolysis

This chaining of sugars relies on the formation of bridges of oxygen atoms.

Glycoside Bonds

are simple sugars that cannot be hydrolyzed to a simpler

form; there is one sugar molecule.

Monosaccharides

The most

common hexose monosaccharides include

Glucose, fructose, and galactose.

Are formed when two monosaccharide units are joined by a glycosidic

linkage.

Disaccharides

On hydrolysis, disaccharides will be split into two monosaccharides by

Disaccharides enzyme (example: lactase) located on the Microvilli on the intestine.

The most common disaccharides are:

maltose (comprising two d-glucose molecules in a 1 → 4 linkage), lactose, and sucrose

chaining of 3 to 10 sugar units

Oligosaccharides

formed by the linkage of many monosaccharide units. 10 or more sugar units.

Oligosaccharides

an enzyme found in saliva and in the stomach,

hydrolyzes starch to disaccharides in the duodenum.

Amylase

he most common polysaccharides are starch (plant based glucose molecules) and glycogen (animal based glucose molecules)

starch (plant based glucose molecules) and glycogen (animal based glucose molecules)

these carbohydrates can reduce other compounds while they themselves are oxidized

Reducing substances

T o be a reducing substance, the carbohydrate

must contain an

active (available) ketone or an aldehyde group

Carbohydrates can form glycosidic bonds with other carbohydrates and with

noncarbohydrates.

n

forming the glycosidic bond, an ______ is generated on one sugar (at carbon 1) in place of the

hemiacetal.

Acetal

Examples of common-reducing sugars

Glucose, maltose, fructose, lactose, and galactose.

If a glycosidic bond is formed with the anomeric carbon on the

other carbohydrate, the resulting compound is

no longer a reducing substance.

Nonreducing

carbohydrates do not have an active ketone or aldehyde group and therefore will not reduce

other compounds.

The most common nonreducing sugar

Sucrose - table sugar.