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CarbohydratesIB Biology

1Molecular Models KitsIn your groups, you have a kit. We will be making models with these over the next several class periods. To begin, in your warmup book, make a new page and title it, Molecular Models Activity. You will number each one, draw it, and get an initial. #1- Water, H2O#2- Methane, CH4 Build these models now and get them initialed. Review: Polymer Principles Four classes of macromolecules: Carbohydrates Lipids Proteins Nucleic Acids Polymers are made up of smaller parts called monomers. Polymers are formed through condensation reactions. Polymers are broken apart through a hydrolysis reaction. General Information about Carbohydrates Carbohydrates are composed of C, H, and O CH2O(CH2O)x C6H12O6

Carbo-contains carbon Hydrate- Compound containing chemically combined water.Often end in -ose

Is this a carbohydrate?

Is this a Carbohydrate?

Is this a carbohydrate?

Is this a Carbohydrate?

General info about carbohydratesFunctions: Immediate energy source for cells Energy storage for later use Raw material for building other molecules Important role in cell membrane recognition

About 17 KJ of energy per dry gram. About the same as protein, but that of lipids

Monosaccharides -one sugar unit (monomer) are the simplest carbohydrates Backbone of 3-7 carbon atoms Form ring structures in cells Characterized by sweet taste Have several polar -OH groups, so they are soluble in water. (The many OH groups can hydrogen bond with water molecules)

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Carbons are numberedOn your lab paper, draw GlucoseNumber the carbons

On your glucose, circle all the hydroxyl (OH) groups

Label the slight positive and slight negatives on the highlighted Os and Hs. HINT: Remember polarity and unequal pull of electrons

Using the molecular model kits, build a model of glucose

Notice orientation of hydroxyl (OH) groupsInitial when complete GlucoseC6H12O6 A product of photosynthesis Needed for ATP synthesis during cellular respiration

Draw a water molecule hydrogen bonding off of EACH highlighted H and EACH highlighted O.

Be sure you correctly orient the Hs and Os of the water molecule Show the hydrogen bond with a dotted line (you should end up drawing 10 H2Os) Some example monosaccharidesGlucoseRiboseDeoxyriboseFructoseDeoxyribose and ribose are the building blocks for nucleic acids.

Found in DNAFound in RNA**FructoseFound in fruitsUsed by plants to attract animals to the fruit for seed dispersal.

IsomersGlucose and fructose have the same chemical formula C6H12O6 but different structural arrangement of the atoms (called isomers)

The monosaccharides glucose, fructose, and galactose are isomers.

They contain the same atoms but in different arrangementsAll are C6H12O6

DisaccharidesDi = 2Saccharide = sugar

Disaccharides are formed in Condensation Reactions

http://kisdwebs.katyisd.org/campuses/MRHS/teacherweb/hallk/Teacher%20Documents/AP%20Biology%20Materials/Chemistry%20of%20Life/Condensation%20and%20Hydrolysis%20Reactions/conde_shell.html

Maltose (two glucose units) provides energy for germinating seeds.

H2OFormula: C12H22O11 (glucose + glucose H2O)Maltose between which carbon #s are the glucoses connected?

H2O

Sucrose (glucose + fructose) is a transport form of sugar used by plants and harvested by humans for food.

Lactose (galactose and glucose) is present in milk

Splenda: A modified disaccharideSplenda is just a modified form of sucroseNotice the chloride ions that replace the hydroxyl groups

Maltose- (2 Glucoses) Malt Sugar

On your lab drawings paper, draw 2 glucoses next to each other.

-On your first glucose, highlight the hydroxyl (-OH) on carbon 1. -On your second glucose, highlight the hydroxyl (-OH) on carbon 4.

Using the molecular model kits: BUILD MALTOSE

Notice orientation of hydroxyl (-OH) groups. When finished with maltoseCombine each groups maltoses to make one long chain. Draw this. This is a model of starch.

Complex Carbohydrates:The PolysaccharidesPolymers of hundreds or thousands of sugar monomers costs little energy to build easily reversible = release energy when digested

Storage PolysaccharidesWhat does it mean to store something?

Storage PolysaccharidesStarch (polymer of glucose) Found in PLANTS Formed in roots and seeds as a form of glucose storage

Glycogen (polymer of glucose) Found in ANIMALS Formed in the liver and muscles as a form of glucose storage

Structural PolysaccharidesCellulose (polymer of glucose) Most abundant organic compound on Earth Found in the cell walls of plants Indigestible for most animals due to orientation of bonds between glucoses

Structural PolysaccharidesChitin (polymer of modified glucose units) Found in the outer coverings of insects, crabs, and spiders Found in the cell walls of many fungi

Starch vs. Cellulose

Starch:Polymer of a-glucoseHighly branchedHas a 1-4 linkagesUsed for storage in plants.

CellulosePolymer of b-glucoseLinear, does not branchHas b 1-4 linkagesMost animals lack the enzyme to break the b 1-4 linkages (so we cant digest it).

Digesting starch vs. cellulose

starcheasy todigestenzymeenzyme

cellulosehard todigest44Starch = all the glycosidic linkage are on same side = molecule lies flat

Cellulose = cross linking between OH (H bonds) = rigid structureCowcan digest cellulose well; no need to eat other sugars

Gorillacant digest cellulose well; must add another sugar source, like fruit to diet

45The digestion of cellulose governs the life strategy of herbivores.Either you do it really well and youre a cow or an elephant (spend a long time digesting a lot of food with a little help from some microbes & have to walk around slowly for a long time carrying a lot of food in your stomach)Or you do it inefficiently and have to supplement your diet with simple sugars, like fruit and nectar, and youre a gorilla.

APBioTOPICS/20Biochemistry/MoviesAP/Macromolecule-Lifewire.swfHelpful bacteriaHow can herbivores digest cellulose so well?BACTERIA live in their digestive systems & help digest cellulose-rich (grass) meals

RuminantsTell me aboutthe rabbits,again, George! I eatWHAT!

46Summary of CarbohydratesMonosaccharides: Glucose, Fructose, Galactose, Ribose

Disaccharides: Lactose, Maltose, Sucrose

Polysaccharides: Starch, Cellulose, Glycogen, ChitinAlpha (starch) & Beta (cellulose) linkages

Chitin: exoskeleton, suture, and fungi (cell walls)