Organic MoleculesBio

First Five

Compare and contrast

monosaccharides and

disaccharides.

• Cell Structure Unit Exam• Corrections due no later than,

Thursday, February 27• Quiz: Carbohydrates & Lipids

• Friday, February 28

Today’s Announcements

Table Groups

On a whiteboard, draw a Venn diagram to compare and contrast monosaccharides and disaccharides.

The many forms of glucose: Straight chain(linear) form

(least common/stable)

α-Ring formAlpha-ring(“OH” group is below the ring)

β-Ring formBeta-ring(“OH” group is above the ring)

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Cyclic Structure of Glucose: RotationStraight open-chain glucose is so reactive that

almost all molecules quickly rearrange their bonds to form two new structures. These structures are six-membered rings like those below. The beta version is more stable.

• Fruit sugar• E.g. high

fructose corn syrup

• Main component of DNA and RNA

• Very important at the cellular level

• Found with glucose (lactose) in dairy products

Fructose Ribose Galactose

Other important monosaccharides

GLUCOSE AND GALACTOSESlightly different structure= entirely different function

DISACCHARIDES!

Combining monosaccharides to make…Glucose Glucose

Maltose

More Disaccharides:Table sugar

Glucose Fructose

Sucrose

More Disaccharides:Dairy products

Glucose Galactose

Lactose

How are the two monosaccharides joined?

Glycosidic Bond

However, to form this, another molecule has to be released. Can you figure out what it is?

6C12H6O

12C22H11O

6C12H6O

H2O

How are the two monosaccharides joined?

Glycosidic Bond

+H2O

Partner PracticeDraw the monosaccharides below on a whiteboard. Then, choose a disaccharide to make by doing the reaction.

• Monosaccharides:• Fructose• Glucose• Galactose

• Disaccharide:• Sucrose• Lactose

First Five1. What is the chemical formula for glucose?2. Describe the differences between the 3 forms of glucose.

• Cell Structure Unit Exam• Corrections due no later than,

Thursday, February 27• Quiz: Carbohydrates & Lipids

• Friday, February 28 [Gold 1]

Today’s Announcements

Can you…Draw on the diagram where a glycosidic bond will form and complete the diagram to show the disaccharide that will be produced.

Individual Practice - Disaccharides

Can you…Draw on the diagram where a glycosidic bond will form and complete the diagram to show the disaccharide that will be produced.

Individual Practice - Disaccharides

PolysaccharidesPolysaccharides are carbohydrate polymers made from many linked monosaccharide monomers to form long chain-like molecules.

- made from glucose

monomers

polysaccharides cellulose

glycogen

starch

There are three main types of naturally occurring polysaccharides. They are cellulose, glycogen, and starch that are of major importance.

Polysaccharides Derived from Glucose

Polysaccharides Derived from Glucose

Cellulose:used to construct cell walls in plants

Glycogen:energy storage in animals (e.g. in liver and muscle tissues)

Starch:energy storage in plants

PolysaccharidesFunctions: storage, structure, recognition

• Starch and glycogen are storage molecules • Chitin and cellulose are structural

molecules • Cell surface polysaccharides

(polysaccharides embedded in the cell surface membrane) are recognition molecules

Starch• Starch is a plant storage

polysaccharide • There are two forms of chains in

starch• amylose• amylopectin

• Most starch is 10-30% amylose and 70-90% amylopectin

• Amylose: compact, energetic spirals of α-glucose molecules

• Amylopectin: compact, branched, energetic shapes of α-glucose molecules

Starch

First FiveDescribe the similarities and differences between the two types of chains in starch: amylose and amylopectin.

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Amylose has an unbranched structure.

Polysaccharides Derived from GlucoseStarch

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Polysaccharides Derived from Glucose

Amylopectin has a branched structure.

Starch

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An important reaction during digestion is the hydrolysis of starchy foods as shown below.

Polysaccharides Derived from Glucose

starch disaccharides glucose

Starch

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Glycogen is a carbohydrate polymer that is stored in the liver and muscle tissues in animals. It is the energy-storage carbohydrate in animals.

Polysaccharides Derived from GlucoseGlycogen

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Glycogen has a structure similar to amylopectin (starch) except that it is more highly branched

Polysaccharides Derived from GlucoseGlycogen

Polysaccharides Derived from Glucose• Cellulose is a plant structure

molecule.• It is the most abundant organic

molecule• found in all cell walls• breaks down very slowly in nature

Cellulose

Polysaccharides Derived from Glucose• Cellulose is formed from the β-

glucose molecules• β-glucose forms more hydrogen

bonds because of the orientation of the –OH group on each glucose ring.

• Both starch and glycogen are formed from α-glucose molecules

Cellulose

Polysaccharides Derived from Glucose

Practice with Vocab: Frayer Models

In your notebook, Create a frayer model for the following topics: Monosaccharide, Disaccharide, PolysaccharideDefinition: Characteristics:

Drawing of structure: Example:(Write topic

here)

Polysaccharides Practice ProblemsBegin in class.Finish as homework.

• DUE WEDNESDAY