The Chemistry of Life What are living creatures made of? Why do we have to eat?

96% of living organisms is made of: carbon (C) oxygen (O) hydrogen (H) nitrogen (N) Elements of Life

Molecules of Life Put C, H, O, N together in different ways to build living organisms What are bodies made of? –carbohydrates sugars & starches –proteins –fats (lipids) –nucleic acids DNA, RNA

Carbohydrates

Sugars = building blocks Names for sugars usually end in –glucose –fructose –sucrose –maltose OH H H HO CH 2 OH H H H OH O glucose C 6 H 12 O 6 sucrose fructose maltose -ose

Sugar Has Many Disguises Careful reading of labels is necessary to know how much added sugar you are getting. Sometimes sugar masquerades as apparently more “healthy” ingredients, Here is a list of some of the possible code words for “sugar” which may appear on a label. Hint: the words “syrup”, “sweetener”, and anything ending in “ose” can usually be assumed to be “sugar”. Agave NectarAgave Nectar Maltodextrin Barley Malt Syrup Malt syrup Corn sweetener Maltose Corn syrup, or corn sugar Maple syrup Dehydrated Cane Juice Molasses Dextrin Raw sugar Dextrose Rice Syrup FructoseFructose Saccharose Fruit juice concentrate Sorghum or sorghum syrup Glucose Sucrose High-fructose corn syrup Syrup Honey Treacle Invert sugar Turbinado Sugar Lactose Xylose

Carbohydrates: OH H H HO CH 2 OH H H H OH O Energy molecules

sucrose Carbohydrates Function: –quick energy –energy storage –structure Example –sugars –starches –cellulose (cell wall) glucose C 6 H 12 O 6 starch

Carbohydrates Building block molecules = sugar sugar - sugar - sugar - sugar - sugar Simple sugars

BIG carbohydrates Starch –energy storage in plants potatoes Glycogen –energy storage in animals in liver & muscles Cellulose –structure in plants cell walls Chitin –structure in arthropods & fungi exoskeleton

Building BIG carbohydrates glucose + glucose + glucose… = starch (plant) glycogen (animal) energy storage polysaccharide

Digesting starch vs. cellulose starch easy to digest cellulose hard to digest enzyme

Cellulose Cell walls in plants –herbivores can digest cellulose –most carnivores cannot digest cellulose that’s why they eat meat to get their energy & nutrients cellulose = roughage

Cow can digest cellulose well; no need to eat other sugars Gorilla can’t digest cellulose well; must add another sugar source, like fruit to diet

Helpful bacteria How can cows digest cellulose? –bacteria live in their stomachs & help digest cellulose-rich (grass) meals

Building carbohydrates Synthesis | glucose | glucose monosaccharides 2 sugars = disaccharide | maltose

Lipids: Fats & Oils

Lipids Examples –fats –oils –waxes –hormones sex hormones –testosterone (male) –estrogen (female)

Lipids Function: –energy storage very concentrated twice the energy as carbohydrates! –cell membrane –cushions organs –insulates body think whale blubber!

Molecular Structure of Fat not a chain (polymer) = just a “big fat molecule”

Lipids Concentrated energy molecules

Other lipids in biology Cholesterol –good molecule in cell membranes –make hormones from it including sex hormones –but too much cholesterol in blood may lead to heart disease

Other lipids in biology Cell membranes are made out of lipids –phospholipids –heads are on the outside touching water “like” water –tails are on inside away from water “scared” of water –forms a barrier between the cell & the outside

Saturated fats Most animal fats –solid at room temperature Limit the amount in your diet –contributes to heart disease –deposits in arteries

Unsaturated fats Plant, vegetable & fish fats –liquid at room temperature the fat molecules don’t stack tightly together Better choice in your diet

Saturated vs. unsaturated saturatedunsaturated

Trans fats → Hydrogenation

Trans Fatty Acids Hydrogenated & Partially Hydrogenated Oils: Proven Serious Health Effects After closely analyzing data from scientific studies and reviews, many countries (in our country many states) have either banned hydrogenated and partially hydrogenated oils altogether or have instituted future dates for elimination of their use in foods. These government actions concerning the trans fatty acids (hydrogenated and partially hydrogenated oils) is directly related to studies that link trans fatty acid (hydrogenated and partially hydrogenated oil) consumption from processed foods to the development of diabetes, cancer and cardiovascular disease.

Proteins

Proteins: Multipurpose molecules

Proteins Building block = amino acid amino acid – amino acid – amino acid – amino acid – —N——N— H H H | —C— | C—OH || O variable group amino acids  20 different amino acids

Amino acid chains Proteins –amino acids chained into a polymer  Each amino acid is different  some “like” water & dissolve in it  some “fear” water & separate from it

Its shape that matters! Proteins do their jobs, because of their shape Unfolding a protein destroys its shape –wrong shape = can’t do its job –unfolding proteins = “denature” temperature pH (acidity) folded unfolded “denatured”

This is the longest word in the English language characters which is the name of a protein, but the word is actually the arrangement of the a.a’s that make up the protein! Methionylglutaminylarginyltyrosylglutamylserylleucylphen- ylalanylalanylglutaminylleucyllysylglutamylarginyllysylgluta- mylglysylalanylphenylalanylvalylprolylphenylalanylyalylthre- onylleucylglcycylaspartylprolylglicylisoleucyglutamylgluta- minlserylleucyllysylisoleucylaspartylthreonylleucylisoleu- cylglutamylalanylglyclyalanylaspartylalanylleucyglutamylle- ucylgluycylisoleucylproluylphenylalanyserylaspartyprolylleu- celalanylaspartylglycylprolylthreonylisolleucyglutaminylaspa- raginylalanythreonylleucylarginylalanylphenylalanylalanylal- anylglycylvalylthreonylprolylalanylglutaminylcysteinylphen- ylalanylglglutamylmethionylleucyalanylleucylisoleucylarginyl- glutaminyllysylhistidylprolyuthreonylisoleucylprolylisoleuc- ylglycylleucylleucylmethionyltyrosylalanylasbaraginylleucyl- valylphenylalanylsparaginyyllysylglycylisoleucylaspartylglut- amylphenylalanylyltyrosylalanylglutaminylcysteinylglutamyll- ysylvalylglycylvalylspartylserylvalylleucylvallalanylaspart- ylvalylprolylvalvlglutaminylglutamylserylalanylprolylpheny- lalalrginylglutaminylalanylalanylleucylarginylhistidylasp- araginylvalylalalprolylisoleucylphenylalanylisoleucylcystei- nylprolyprolylaspartylalanylaspartylaspartyspartyleucylle- ucylarginylglutaminylisoleucylalanylseryltyroslglycylargin- ylglycyltyrosylthreonyltyrosylleucylleucylserylarginlalanyl- glycylvalylthreonylglycylalanylglutamylasparaginylarginyla- nylalanylleucylprolylleucylaspaaginylhistidylleucylvalylalan- yllysylleucyllysylglutamyltyrosylasparagimylalanylalanypro- lylprolylleucylglutaminylglycylphenlalanylglycylisoleyucyls- erylalanylprolylaspartylglutaminylvalyllysylalanylalanylisol- eucylalspartylalanylglycylalanylalanylglycylalanylasoleucylse- rylglycylserylalanylisoleucylbalyllysylisoleucylisoleucylgluta- mylglutaminylhistidylasparaginylisoleucylglutamylpronylglu-0 tamyllysylmethionylluecylalanylalanyoeucyllysylvalylpheny- lalanylvalylglutamilylprolylmethionyllysylalanylalanylthreo- nylarginylserine

Proteins insulin collagen (skin) hemoglobin Examples –muscle –fingernails, claws –skin –hair –enzymes example: pepsin –hormones example: insulin

Proteins Function: –many, many functions hormones –insulin movement –muscle immune system –protect against germs enzymes –help chemical reactions

Nucleic acids

Enzymes: “Helper” Protein molecules

Flow of energy through life Life is built on chemical reactions

Chemical reactions of life Processes of life –building molecules synthesis –breaking down molecules digestion ++

Nothing works without enzymes! How important are enzymes? –all chemical reactions in living organisms require enzymes to work building molecules –synthesis enzymes breaking down molecules –digestive enzymes –enzymes speed up reactions ++ enzyme We can ’ t live without enzymes!

Examples  synthesis  digestion ++ enzyme

Enzymes are proteins Each enzyme is the specific helper to a specific reaction –each enzyme needs to be the right shape for the job –enzymes are named for the reaction they help sucrase breaks down sucrose proteases breakdown proteins lipases breakdown lipids DNA polymerase builds DNA Oh, I get it! They end in -ase

Enzymes aren’t used up Enzymes are not changed by the reaction –used only temporarily –re-used again for the same reaction with other molecules –very little enzyme needed to help in many reactions enzyme substrateproduct active site

It’s shape that matters! Lock & Key model –shape of protein allows enzyme & substrate to fit –specific enzyme for each specific reaction

1 2 3

Enzyme vocabulary Enzyme –helper molecule Catalyst = enzyme Substrate –molecule that enzymes work on Enzyme-substrate complex –enzyme & molecule temporarily joined Active site –part of enzyme that substrate molecule fits into

What affects enzyme action 1. Correct protein structure –correct order of amino acids –why? enzyme has to be right shape

What affects enzyme action? 2. Temperature –why? –enzyme has to be right shape 3. pH (acids & bases) –why? –enzyme has to be right shape

More about Enzymes: What Affects Enzymes

Enzyme concentration Effect on rates of enzyme activity –as increase amount of enzyme = increases how fast the reaction happens more enzymes = more frequently they collide with substrate

Enzyme concentration amount of enzyme reaction rate What’s happening here?!

Substrate concentration Effect on rates of enzyme activity –as increase amount of substrate = increases how fast the reaction happens more substrate = more frequently they collide with enzyme

Substrate concentration amount of substrate reaction rate What’s happening here?!

37° Temperature temperature reaction rate What’s happening here?!

Temperature Effect on rates of enzyme activity –Optimum temperature greatest number of collisions between enzyme & substrate human enzymes = 35°- 40°C (body temp = 37°C) –Raise temperature denature protein = unfold = lose shape –Lower temperature T° molecules move slower decrease collisions

How do cold-blooded creatures digest?

7 pH reaction rate stomach pepsin intestines trypsin What’s happening here?!

pH Effect on rates of enzyme activity –pH changes protein shape –most human enzymes = pH 6-8 depends on where in body pepsin (stomach) = pH 3 trypsin (small intestines) = pH 8

For enzymes… What matters? SHAPE!

Reviews everything about enzymes Active site, lock & key, factors that affect