chapter 2-basic chemistry biology 112 tri-county technical college pendleton, sc
TRANSCRIPT
Chapter 2-Basic Chemistry
Biology 112Tri-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