CHAPTER 2

CHEMISTRY OF LIFE

NATURE OF MATTER

HOW IS CHEMISTRY RELATED TO BIOLOGY?

REVIEW: DRAW AN ATOM THAT HAS 8 ELECTRONS

NATURE OF MATTER

ELEMENTS–PURE, ONE TYPE OF ATOM

–ELEMENTS DIFFER IN #OF PROTONS

CHEMICAL BONDING

BONDING = CMPDSOCCURS BECAUSE ATOMS WANT FULL ENERGY SHELLS

COVALENT BONDS

SHARING OF ELECTRONSUSUALLY BTWN NON-METALS

Ex. Water, carbon dioxide

HYDROGEN BONDS

A WEAK ATTRACTION BETWEEN TWO POLAR MOLECULES

WHY IS WATER POLAR?

WATER HAS AN UNEQUAL CHARGE

OXYGEN = NEGATIVEHYDROGEN = POSITIVE

IONIC BONDS

ATOMS LOSE OR GAIN ELECTRONS (IONS FORM)

IONS OF OPPOSITE CHARGE ATTRACT

METALS AND NON-METALS

WATER’S SPECIAL PROPERTIES

YOU ARE 70% WATERWATER CAN ABSORB AND STORE LARGE AMOUNTS OF ENERGY (GOOD INSULATOR)

WATER CONT.

WATER ALLOWS ORGANISMS TO CONTROL THEIR TEMP. (HOMEOSTASIS)

WATER CONT.

COHESION–ATTRACTION OF WATER TO ITSELF

–BEADING, SURFACE TENSION

WATER CONT.

ADHESION–WATER’S ATTRACTION TO OTHER POLAR SUBSTANCES

WATER CONT.

ADHESION LETS WATER MOVE UP NARROW TUBES–CAPILLARY ACTION–STEMS OF PLANTS

WATER CONT.

WATER IS THE UNIVERSAL SOLVENT (POLARITY)

WHAT IS A SOLVENT?

WATER CONT.

NONPOLAR SUBSTANCES DO NOT DISSOLVE IN WATER

EX. OIL

CHEMISTRY OF CELLS

FOUR CLASSES OF MACROMOLECULES THAT HELP YOUR BODY FUNCTION–ORGANIC (CARBON CMPDS)

CARBOHYDRATES

MADE OF C, O, HKEY ENERGY SOURCEMADE OF SIMPLE SUGARS - MONOSACCHARIDES

CARBS CONT.

SIMPLE SUGARS: GLUCOSE, FRUCTOSE, GALACTOSE

COMBINATIONS OF THESE FORM DI AND POLYSACCHARIDES

CARBOHYDRATE STRUCTURE

CARBS CONT.

POLYSACCHARIDES ARE ENERGY STORAGE MOLECULES–STARCH / CELLULOSE – PLANTS

–GLYCOGEN - ANIMALS

HOMEWORK

CARBOHYDRATES

IN EACH BOX:

PLACE THE CATEGORY OF CARBOHYDRATE AND EXAMPLES OF EACH

ANSWER THE FOLLOWING QUESTIONS

CARBOHYDRATES ARE A READY SOURCE OF ____?

ANIMALS CANNOT DIGEST ____?

CARBS ARE BUILT UP FROM MONOSACCHARIDES OR ____ ____?

ANIMALS STORE EXTRA ENERGY AS _____?

SIMPLE SUGARS ARE MADE BY PLANTS DURING ____?

ANIMALS STORE GLYCOGEN IN ____ AND THE ____.

LIPIDS

NONPOLARFATS, PHOSPHOLIPIDS, STEROIDS, WAXES

IMPORTANT IN THE STRUCTURE OF CELLS

LIPIDS CONT.

TYPICAL FATS CONTAIN THREE FATTY ACIDS–HYDROCARBONS – MADE OF ONLY C AND H

–THE BONDS BETWEEN C AND H ARE RICH IN ENERGY

LIPIDS CONT.

SATURATED FATS– NO DOUBLE BONDS– ANIMAL FATS, SOLID AT ROOM TEMP

UNSATURATED FATS– ON OR MORE DOUBLE BONDS– PLANT FATS , LIQUID AT ROOM TEMP

LIPIDS CONT.

UNSATURATED FATS ARE MORE HEALTHY–THE DOUBLE BONDS CREATE A KINK THAT MAKES IT HARDER FOR THE FAT TO STICK TO ARTERIES

LIPIDS CONT.

MADE OF 1 GLYCEROL AND 3 FATTY ACIDS

CONSUMPTION OF ARTIFICIAL FATS CAN LEAD TO VITAMIN DEFICIENCIES

HOMEWORK

LIPIDS

IN EACH BOX:

PLACE THE CATEGORIES OF LIPIDS AND EXAMPLES OF EACH

ANSWER THE FOLLOWING QUESTIONS

Lipids are ____ and do not dissolve in water.

Lipids provide cells with 6x as much ___ as carbs.

Fats are made of one ___ and three __ __.

PROTEINS

MADE OF SMALLER UNITS CALLED AMINO ACIDS–20 DIFFERENT KINDS–CONTAIN NITROGEN

BONDS BETWEEN AMINO ACIDS = PEPTIDE BOND

MANY AMINO ACIDS=MANY PEPTIDE BONDS=POLYPEPTIDE

POLYPEPTIDE IS ANOTHER NAME FOR PROTEINS

PROTEINS CONT.

12 AMINO ACIDS CAN BE MADE BY THE BODY

THE LAST 8 MUST BE CONSUMED IN OUR DIET– ESSENTIAL AMINO ACIDS

PROTEINS CONT.

FOLD INTO COMPLEX SHAPES (ACTIVE)

BECOME VERY STRONG WHEN FOLDED

EX. COLLAGEN, KERATIN, ANTIBODIES, HEMOGLOBIN, HORMONES

PROTEINS CONT.

ENZYMES–SPEED UP CHEMICAL RXNS–AFFECTED BY pH, HEAT

DENATUREDWHY HOMEOSTASIS IS IMPORTANT

NUCLEIC ACIDS

LONG CHAIN OF NULCEOTIDES–THREE PARTS

SUGAR, NITROGEN BASE, PHOSPHATE

NUCLEIC ACIDS CONT.

TWO TYPES–DEOXYRIBONUCLEIC ACID (DNA)DOUBLE STANDED, GENETIC INFO

NUCLEIC ACIDS CONT.

RIBONUCLEIC ACID (RNA)–SINGLE STRANDED–HELPS IN THE MANUFACTURING OF PROTEINS

ATP

ADENOSINE TRIPHOSPHATE–NUCLEOTIDE WITH 2 EXTRA PHOSPHATE GROUPS (HIGH ENERGY)

ENERGY FOR LIFE PROCESSES

AS CHEMICAL BONDS ARE MADE AND BROKEN ENERGY IS EITHER STORED OR RELEASED

ENERGY CONT.

EX. WATER FREEZES–EXERGONIC

EX. ICE MELTS–ENDERGONIC

ENERGY CONT.

ACTIVATION ENERGY–ENERGY NEEDED TO START A RXN

–“CHEMICAL PUSH”

ENERGY CONT.

ENZYMES–CATALYSTS THAT LOWER ACTIVATION ENERGY

–WITHOUT THEM, RXNS WOULD NOT HAPPEN FAST ENOUGH TO SUSTAIN LIFE

Reaction pathway without enzyme

Reaction pathway with enzyme

reactants

products

Activation energy needed without an enzyme

Activation energy needed with an enzyme

ENERGY CONT.

EX. CARBONIC ANHYDRASE–WITHOUT IT THE BLOOD COULD NOT QUICKLY CARRY AWAY THE CO2 PRODUCED BY CELLS

ENERGY CONT.

ENZYME SPECIFICITY–ENZYMES ACT ON ONE SPECIFIC SUBSTANCESUBSTRATEEX. AMYLASE - STARCHEX. CATALASE - PEROXIDE

ENERGY CONT.

ENZYMES/SUBSTRATES HAVE LOCK AND KEY FIT

ENZYMES HAVE ACTIVE SITES WHERE THE SUBSTRATE BONDS

ENERGY CONT.

AT THE ACTIVE SITE, THE SUBSTRATE IS TRANSFORMED INTO NEW PRODUCTS

ENERGY CONT.

IF THE ACTIVE SITE IS CHANGED:–SUBSTRATE DOES NOT FIT

–REACTION DOES NOT HAPPEN

ENERGY CONT.

WHAT CHANGES THE ACTIVE SITE?–DENATURATION

HEAT, pHWHY THEN WOULD A FEVER OF 105 BE FATAL?

WRAP UP

WHAT THEME IS STRESSED MOST IN THIS CHAPTER?–HOMOESTASIS –ENERGY