Chapter 2-Basic Chemistry

Biology 110Tri-County Technical College

Pendleton, SC

Organic CompoundsText defines organic compound as containing “carbon”Where would one put CO2?

Prefer to expand organic as containing both carbon and hydrogen(s)Carbohydrates, lipids, proteins, and nucleic acids are organicWater, salts, acids, and bases are inorganic

Water, water everywhere…

Water is crucial to living systemsHigh heat capacity

Holds heat and releases it slowly

Excellent solvent because of its polarityInvolved in some reactions essential for lifeProtects certain organs (brain/spinal cord)

Salts and ElectrolytesSalts are ionic compounds= anion (-) and cation (+)Separate into ions when dissolved in waterAll salts are electrolytes because they conduct electrical current in solutionCalcium and Phosphorus most plentifulSodium and potassium essential to nerve impulses

Acids with examplesAcid is substance that can release hydrogen ions (H+) in detectable amounts

Also called proton donors

Hydrochloric acid is good exampleHClH+ + Cl-

Other acids include acetic and carbonic

Acids that release all their protons called strong acidsAcids that ionize incompletely (acetic/carbonic) are called weak acids

Who’s on first?Base is known as “proton acceptor”Hydroxides = common inorganic basesRelease hydroxyl ion (OH-) into solution

NaOHNa+ + OH-

Any base containing this ion is strong base

Bicarbonate ion (HCO3-) is weak base

When acids and bases mixed = water and a saltHCl + NaOH H2O + NaCl

Neutralization reaction

pH and more…pH stands for “potential hydrogen” and is measure of [ ]s of hydrogen ions in various fluidsNumber of protons in solution expressed in terms of moles per literpH of 7 has equal amounts of protons and hydroxyl ions and is NEUTRAL

Neither acidic nor basic

pH, continuedpH lower than 7 = acidicpH higher than 7 = basic

Let’s be real careful with our verbalizations

pH scale is LOGARITHMICBUFFER is substance that can react with strong acid or base to form weaker acid or base and thus resist changes in pH

More on buffersBlood ph normally 7.35-7.45Changes of more than few tenths of pH unit = auf wiedersehenImportant buffering systems of human body include

Protein buffering systemCarbonic acid-bicarbonate buffering systemPhosphate buffering system

Organic compounds and Life

Four classes of organic compounds essential to/for lifeCarbohydrates, lipids, proteins, and nucleic acidsAll are macromolecules (polymers)Review: polymers are constructed of identical or similar repeating subunits called monomers

CarbohydratesIncludes the starches and sugarsContain carbon, hydrogen, and oxygenTranslated into “hydrated carbon”Ratio of 2 hydrogen atoms to one oxygen atomConsists of the mono, di, and polysaccharidesLeft out the oligosaccharides for good reason (3-20)

MonosaccharidesOne or “simple” sugarRatio of CxH2xOx

Glucose (hexose) is blood sugar and universal cellular fuelFructose, galactose, ribose and deoxribose are important monosaccharides

Disaccharides

“Di” means two or double sugarImportant disaccharides include sucrose (glucose/fructose), lactose (glucose/galactose), and maltose (glucose/glucose)REVIEW: dehydration synthesis (condensation reaction) and hydrolysis

Chalk talk time on where’s the water?

Polysaccharides“Poly” means manyLong branching chains of linked simple sugarsStarch is plant form of carbohydrate storageGlycogen is animal store form

Short supply stored in liver/muscle cells

Cellulose is most abundant organic material on Earth—care for some fiber?

Lipids Includes the neutral fats, phospholipids, and steroidsContain C, H, and O’s but C and H’s far outnumber the O’sTristearin = C57H110O6

Most lipids insoluble in water but dissolve in other lipids and organic solvents such as alcohol, ether, and acetone

Lipids, continuedNeutral fats (triglycerides) composed of glycerol and fatty acids (chalk talk time)Are body’s most abundant and [ ]ed source of usable energyPhospholipids (chalk talk time again)

Phosphate part always “charged” giving it special properties

Review: hydrophilic versus hydrophobicMajor part of cellular membranes

Steering the steroids…Basic structure of three 6- and one 5-carbon ringsFat solubleCholesterolvitamin D, sex hormones, cortisol, and bile salts“Atherosclerosis” (deposits of fatty substances on artery walls and “Arteriosclerosis” (hardening of arteries)Some anabolic steroids, guys?????

Proteins, fibrous and globular

Account for > 50% of organic matter in bodyConstructive materials, cell function, metabolism, and protectionC, H, O, and N (sometimes S)Polymers constructed of monomers of amino acids (20 common to living systems)Chalk-talk time again…YEAH!!!!

Proteins, continuedAA chains of less than 50 AAs called polypeptides (let’s not get picky)FIBROUS proteins=structural proteins

Collagen (most abundant protein in body) found in bones, cartilage, and tendonsKeratin = hair, nails, and skin tougher

GLOBULAR proteins=functional proteins

Motile, play role in nearly all biological processes although quite unstableAntibodies, hormones, & enzymes

Enzymes and moreAre functional proteins that act as biological catalysts

Catalyst is substance that >s rate of reaction without becoming part of product or being changed itself

Chalk-talk time on substrates, active site, apoenzyme, holoenzyme, competitive and noncompetitive inhibition

Enzymes, continuedMost named according to specific type of reaction catalyzed

Hydrolases add waterOxidases cause oxidation (what it are?)

In most cases, if it ends in “ase” it is an enzymeFor all intents and purposes, if one does NOT have the enzyme, one is NOT going to run the reaction…enough said

The nucleic acidsDNA (deoxyribonucleic acid) is the genetic materialRNA (ribonucleic acid) responsible for protein synthesisMonomers of both are NUCLEOTIDESGeneric nucleotide=five carbon sugar (pentose), one of 4 nitrogenous bases, and a phosphate group

Oh, she has her mother’s eyes

DNA nucleotide has deoxyribose sugar; A,T,G, or C; and phosphateDouble stranded with strands held together by H bondingGenetic material that contains info directing protein synthesisAll we really got from our parents was info on how to make proteinsMy daddy had his bald head when we buried him…I got some DNA from him for baldness

Ribonucleic Acid (RNA)Nucleotide of RNA contains ribose sugar, A, U, G, or C, and phosphateNO thymines in RNA (uracil)Always constructed single stranded but may double back on itself=globular shapeDoes actual job of protein synthesismRNA, tRNA, rRNAPass the chalk, please!

Some critical conceptsBases are complementaryIn eucaryotes, DNA found in nucleus

Chromatin versus chromosome

RNA puts together proteins (translation) in the cytoplasm from info copied from DNA (transcription)ATP (adenosine triphosphate) is energy coin of the realm

Adenine base, ribose, and 3 phospates

ADP-ATP cycle (energy coupling)

ATP

ATP drives cellular work

Moving Right on Along into Chapter 3