Chapter 15: Carbohydrates

Carbon, oxygen, & hydrogen

Which elements make up carbohydrates?

A molecule with at least one carbon bonded to four different groups

What is a chiral molecule?

monosaccharides

The simplest carbohydrate (think glucose, galactose, & fructose)

disaccharides

consist of two monosaccharides (think lactose, sucrose, & maltose)

polysaccharides

contain more than two monosaccharides

aldehyde & ketone

What kind of groups do monosaccharides contain?

ketohexose

The following monosaccharide is a ______.

aldoses

Aldehyde monosaccharides are called?

ketoses

Ketone monosaccharides are called?

aldotetrose

The following monosaccharide is called?

3-8 carbons

Monosaccharides have how many carbons?

pentose

a monosaccharide with 5 carbons is called a…

triose

a monosaccharide with 3 carbons is called a ….

glucose

Which carbohydrate is known as blood sugar?

achiral

An object whose mirror image is identical to the original and can be superimposed on is …

stereoisomers

When two or more chiral structures have the same molecular formula, but differ in 3D arrangement of atoms

enantiomers

stereoisomers that CANNOT be superimposed on

Glyceraldehyde

What is the COMMON name for the following monosaccharide? (Think: aldotriose)

Threose

What is the COMMON name for the following monosaccharide? (Think: aldotetrose)

Ribose

What is the COMMON name for the following monosaccharide?(Think: aldopentose)

Fructose

What is the COMMON name for the following monosaccharide? (Think: ketohexose)

Fischer Projection

A two dimensional representation of a molecule. Places the most oxidized group at the top. Uses vertical lines for bonds that go backward, horizontal likes for bond that go forward. The intersections of vertical & horizontal lines represent a carbon atom that is usually chiral

The hydroxyl (-OH) group on the chiral carbon farthest from the carbonyl group

What determines whether a monosaccharide is classified as D or L

D

Is this Fischer Projection D or L?

D-Glucose, D-Galactose, D-Fructose because they are all hexoses with the same molecular formula of C₆H₁₂O_6.

What are the most important monosaccharides and why?

D-glucose

Identify the following D monosaccharide.

D-galactose

Identify the following D monosaccharide.

D-fructose

Identify the following D-monosaccharide

fructose

Which monosaccharide is the sweetest?

Haworth structure

The cyclic structure of monosaccharides is called

H on top = alpha (H comes before O) OH on top = beta (think O comes after H

How do you know if a Haworth structure is alpha or beta

alpha D glucose

Identify the following Haworth structure

beta D glucose

Identify the following Haworth structure

alpha D galactose

Identify the following Haworth structure

beta D galactose

Identify the following Haworth structure

alpha D fructose

Identify the following Haworth structure

beta D fructose

Identify the following Haworth structure

carboxylic acids

Monosaccharides that contain an aldehyde group oxidize to

alcohols

Monosaccharides that contain an aldehyde group reduce to

Fructose cannot further oxidize because it has ketone group. It can rearrange its carbons to oxidize into glucose and is further oxidize to a carboxylic acid.

What does fructose oxidize to and explain why.

D-sorbitol

What sugar is commonly used in sugar free products?

reducing

The following sugars are _____ sugars: glucose, fructose, galactose, maltose, & lactose

non-reducing

Polysaccharides are _______ sugars.

Maltose

Glucose + Glucose

Lactose

Glucose + Galactose

Sucrose

Glucose + Fructose

alpha maltose

Identify the following Haworth Structure

alpha (1-4) glycosidic bond

What glycosidic bond does maltose have?

alpha lactose

Identify the following Haworth structure

beta (1-4) glycosidic bond

What glycosidic bond does lactose have?

sucrose

Identify the following Haworth structure

alpha beta (1-2) glycosidic bond

What glycosidic bond does sucrose have?

polysaccharides

What kind of carbohydrates are the following: Amylose, amylopectin, glycogen, cellulose, and starch.

Starch

• A storage form of glucose in plants, found as insoluble granules in rice, wheat, potatoes, beans, and cereals.

• Composed of 2 kinds of polysaccharides: amylose & amylopectin

• unbranched chain of amylose

alpha 1-4 glycosidic bond

what glycosidic bond does amylose have?

amylopectin

• makes up 80% of starch

• is a branched-chain polysaccharide

alpha (1-4) and alpha (1-6) glycosidic bonds

What glycosidic bond does amylopectin have?

Glycogen

• A polymer of glucose that is stored in the liver and muscle of animals

• AKA animal starch

• hydrolyzed in our cells at a rate that maintains the blood level of glucose and provides energy between meals

alpha (1-4) and alpha (1-6) glycosidic bond

What glycosidic bond does Glycogen have?

Cellulose

The major structural unit of wood and plants, gives a rigid cell walls in wood and fiber, cannot be digested by humans because humans cannot break it down

beta (1-4) glycosidic bond

What glycosidic bond does cellulose have?