CHAPTER 17 AND 18

CONCURRENT ENROLLMENT

CARBOHYDRATES• BIOMOLECULE

– Organic compounds essential for life• BIOCHEMISTRY

– Study of compounds and processes associated with living organisms• CARBOHYDRATES

– A polyhydroxyl aldehyde or ketone, or substance that yields such compounds upon hydrolysis

• Monosaccharide– A simple carbohydrate most commonly consisting of 3 to 6 carbon

atoms• Disaccharide

– A carbohydrate formed by the combination of two monosaccharides• Polysaccharide

– A carbohydrate formed by the combination of many monosaccharide units

STEREOCHEMISTRY

• Enantiomers– Mirror images like a hand or 1 and d

glyceraldehyde

• Chiral– A term for compounds or objects that cannot be

superimposed on their mirror image

• Chiral carbon– Carbon atom with four different groups attached

• Learning checks on pages 535 and 537

FISHER PROJECTIONS• Method to look at chiral molecules three-dimensional • With the acid group or the ketone group or the

aldehyde group facing up• The farthest away chiral carbon look at the hydroxyl

or amino group this tells you if it is a D or L family• If the last group is on the right side it is in the D

family• If the last group is on the left side it is in the L family• Learning check page 539 and 540

Continue• Levorotatory

– Rotates plane-polarized light to the left• Dextrorotatory

– Rotates plane-polarized light to the right• Optically active molecule

– A molecule that rotates the plane of polarized light• Living organisms are made up largely of chiral

substances• Both enantiomers will not be found together in the

same biological system• L-lactic acid is found in muscles, while D-lactic acid

is found in sour milk

MONOSACCHARIDES

• Table 17.1 page 541

• With an aldeyde group in a monosaccharide you have a prefix aldo-

• With a ketone group you will have a prefix keto-

• Learning check page 541

• Figure 17.8 gives you the family of D aldoses. MEMORIZE THESE

PROPERTIES• Most monosaccharides are sugars, because they taste

sweet• Table 17.2 page 543• Monosaccharides with at least five carbons exist

predominantly as CYCLIC HEMIACETALS AND HEMIKETALS

• Overhead• Pyranose ring

– A six-membered sugar ring system containing an oxygen atom

Continue• Haworth structure

– Three-dimensional carbohydrate structures• Anomeric carbon

– An acetal, ketal, hemiacetal, or hemiketal carbon atom giving rise to two stereoisomers

• Anomers– Stereoisomers that differ in the three-dimensional arrangement of

groups at the carbon of an acetal, ketal, hemiacetal or hemiketal• Furanose ring

– A five-membered sugar ring system containing an oxygen atom – Page 544 look at drawings– Anomeric carbon is to the right of the oxygen– Hydroxyl group down is α and up is β– Learning check page 546

REACTIONS• Oxidation

– Aldehydes and ketones that have adjacent -OH groups are oxidized by alkaline solutions containing Cu2+

– A sugar that can be reduced by Cu2+ is called a REDUCING SUGAR– Page 547 look at general reaction

• Phosphate ester– Monosaccharides behave as an alcohol and reacts with an acid to form

and ester– Important Intermediates in the carbohydrate metabolism

• Glycoside– Another name for a carbohydrate containing an acetal or ketal group– Page 548 glycosidic linkage and learning check

Important monosaccharides and disaccharides

• Read pages 548-558• Know (draw) ribose, glucose, galactose and maltose• DNA AND RNA are pentoses and are essential in

protein synthesis and the transfer of genetic material • Glucose is a hexose and is found in honey and also

known as blood sugar• Galactose is a hexose and similar to glucose. This is

found in mammal milk

Continue• Maltose is formed from two α-D-glucose linking this

is malt sugar • Lactose is formed from a β-D-Galactose and α-D-

glucose, this makes up 5% of cow’s milk and 7% of human milk

• Surcose is formed from a α-D-glucose and β-D-fructose, found in fruits and sugar cane

• Polysaccharides– Not water soluble– Table 17.4 and overhead– Starch, glycogen, cellulose

CHAPTER 18• Lipid

– A biological compound that is soluble only in NONPOLAR SOLVENTS

• Simple lipid– A ester-containing lipid with just two types of components: an alcohol

and one or more fatty acids• Complex lipid

– An ester-containing lipid with more than two types of components: an alcohol, fatty acids – plus others

• Fatty acids are the fundamental building block for many lipids– They are long-chain carboxylic acids– It is the long nonpolar chain on the fatty acid that gives the oily

characteristics of fats– In the physiological pH the polar head exists as the carboxylate anion –

COO-

FATTY ACIDS• Micelle

– A spherical cluster of molecules in which the polar portions of the molecules are on the surface and the nonpolar portions are located in the interior.

• Figure 18.3 page 567• Fatty acids found in natural lipids have the following

characteristics– They are usually straight-chain carboxylic acids (no branching)– The sizes of most common fatty acids range from 10 to 20 carbons– Fatty acids usually have an even number of carbon atoms (including

the carboxyl group carbon)– Fatty acids can be saturated (containing no double bonds between

carbons). Apart from the carboxyl group and double bonds, there are usually no other functional groups

Continue• Unsaturated fatty acids usually contain double bonds

in the cis- configuration– This forms kinks that result in weaker intermolecular

forces, low melting points and are usually liquid at room temperature

– Overheads• Essential fatty acids

– Fatty acids needed for reactions in the body, but not made in the body

– Linoleic acid and linolenic acid, these are found in fish and plant oils

– They regulate blood pressure, blood clotting, blood lipid levels etc.

STRUCTURE OF FATS AND OILS

• In fats and oils, the alcohol portion is always derived from glycerol, and the acid portion comes from the fatty acids

• Overhead• Learning check 18.1 570• Fat

– A triglyceride that is a solid at room temperature• Oil

– A triglyceride that is a liquid at room temperature• They differ in the degree of unsaturation• Saturated fats influence blood cholesterol

CHEMICAL PROPERTIES• Hydrolysis

– Fats and oils can react with water (only when in the presence of acid or lipase, enzyme) it will reverse the ester formation

– Glycerol and fatty acids are reformed– Learning check 18.2 page 572

• Saponification– Overhead– When triglycerides react with a strong base it will form soap (glycerol

with a salt)– Sodium salts are found in the cake soaps– Potassium salts are found in shaving creams and liquid soaps – Overhead– Learning check 18.3 page 573

Continue• Hydrogenation

– Double bonds of unsaturated fats can be broken when reacting with hydrogen in the presence of a catalyst

– This will decrease the degree of unsaturation and increase the melting point

– This is how margarine and peanut butter are made– During hydrogenation some fatty acids with the common cis-

configuration are isomerized into trans-form. Like margarine• Study skills page 575• Wax

– An ester of a long-chain fatty acid and a long-chain alcohol– Are water-insoluble– In nature are found on feathers, leaves or fruits

• Phosphoglycrides– A complex lipid containing glycerol, fatty acids, phosphoric acid, and

an alcohol component

Continue• Phospholipid

– A phosphorus-containing lipid– Overhead

• Lecithin• A phosphoglyceride containing choline

– +– HO-CH2CH2-N(CH3)3

– This makes one end hydrophilic and the rest of the molecule hydrophobic

– This is very important in forming cell membranes• Cephalin

– A phospholyceride containing ethanolamine or serine– + +

HO-CH2CH2-NH3 and HO-CH2CH-NH3

COO-

Continue• Sphingolipids

– A complex lipid containing sphingosine (page 578), a fatty acid, phosphoric acid, and choline

– Large amounts of sphingomyelin are found in the brain and nerve tissue

• Glycolipid– A complex lipid containing a sphingosine, a fatty acid, and

a carbohydrate– Page 578– When a body cannot break down these complex lipids, due

to a genetic inability to form an enzyme. This causes several human diseases like Tay-Sachs

BIOLOGICAL MEMBRANES

• Prokaryotic cell– A simple unicellular organism that contains no

nucleus and no membrane-enclose organelles

• Eukaryotic cell– A cell containing membrane-enclosed organelles,

particularly a nucleus

• Organelle– A membrane-encased body in the interior of a cell

Continue• Most cells are made up of 40% protein and 60%

lipids– Phosphoglycerides (lecithin and cephlin), sphingomyelin,

and cholesterol• Fluid-mosaic model

– A model of membrane structure in which proteins are embedded in a flexible lipid bilayer

• Lipid bilayer– A structure found in membranes, consisting of two sheets

of lipid molecules arranged so that the hydrophobic portions are facing each other

• Overhead

STEROIDS

• A compound containing four rings fused in a particular pattern

• The most abundant steroid in the human body is cholesterol (very important)

• Overhead• Found in cell membranes and is the building blocks for

sex hormones, vitamin D, bile salts, etc.• Synthesized in the liver• Bile salts

– Yellowish brown or green liver secretion that is stored in the gallbladder

HORMONES

• Chemical messenger secreted by specific glands and carried by the blood to a target tissue, where it triggers a particular response

• Adrenocorticoids– Produced in the adrenal glands by the kidney– Regulates the ion concentration (mainly sodium ions) in body

fluids– Enhances carbohydrate metabolism

• Sex hormones• Testosterone

– Male hormone for development– When these steroids are given to the body it can increase

muscular development but can cause testicular atrophy or a decrease in sperm count

Continue

• Female hormones used in the reproductive process

• Estrogens– Estradiol and estrone

• Progesterone• Prostaglandins

– A substance derived from unsaturated fatty acids, with hormone-like effects on a number of body tissues

– These can regulate menstruations, prevent conception, stimulate blood clotting, it can even be used as an aerosol for asthma

– Overheads