chap 2 chemistry of life
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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