sign in sign up
<<
Home , Deoxyribose, Pentose

CHM 105 & 106 MO1 UNIT SIX, LECTURE SIX 1

CHM 105/106 Program 53: Unit 6 Lecture 6

IN OUR PREVIOUS LECTURE WE JUST BEGAN TALKING ABOUT THE CHAPTER ON WHAT WE CALL

BIOCHEMISTRY, WHICH IS THE DEALING WITH THE COMPOUNDS INVOLVED IN

BIOLOGICAL PROCESSES, LIVING ORGANISMS, BOTH PLANT ANIMAL HUMAN. AND WE HAD JUST

TAKEN A LOOK AT THE FIRST GROUP OF THE FOUR MAJOR GROUPS OF BIOCHEMICAL SPECIES

THAT WE’RE GOING TO LOOK AT. WE’RE MENTIONED THAT WE’RE GONNA LOOK AT

CARBOHYDRATES. WE’RE GOING TO LOOK AT THE LIPIDS. WE’RE GOING TO LOOK AT PROTEINS,

AND WE’RE GOING TO LOOK AT NUCLEIC ACIDS, AND THEIR GENERAL STRUCTURE. THE FIRST

ONE THAT WE MENTIONED AND BEGAN TO LOOK AT WERE THE , AND ONCE

AGAIN THE CARBOHYDRATES ARE THOSE COMPOUNDS THAT CONTAIN , HYDROGEN,

AND , AND SPECIFICALLY AS WE SAW YESTERDAY THAT THESE OFTEN CONTAIN THE

FUNCTIONAL GROUPS OF AND AND ALCOHOLS. THOSE ARE THE THREE

FUNCTIONAL GROUPS THAT WE SEE CONTAINED IN THE CARBOHYDRATES. THE SIMPLEST OF

THE , THE BUILDING BLOCK, THE SINGLE UNIT SUGARS AS WE REFER TO THEM ARE

REFERRED TO AS THE . MONO AS A PREFIX MEANS ONE AND THE

SACCHARIDE IS THE UNIT. YOU MIGHT RECOGNIZE THE LAST PART OF THAT, THE

SACCHARIDE – ONE OF THE FIRST ARTIFICIAL SWEETENERS PRODUCED WAS CALLED

SACCHARINE, AND THE NAME SACCHARINE CAME BECAUSE IT WAS A REPLACEMENT FOR

NATURALLY OCCURRING SUGAR UNITS. WE STARTED ALSO BY TALKING ABOUT THE

SUGARS WHICH THE PENT AS A PREFIX MEANS OF COURSE FIVE PENTANE, WE’RE TALKED

ABOUT EARLIER IN ORGANIC CHEMISTRY. SO THE PENTOSE SUGARS ARE THOSE SUGARS

CONTAINING FIVE . NOW AGAIN PLEASE LET MENTION DON’T WORRY ABOUT

DRAWING OUT ALL THESE STRUCTURES AS I PUT THEM UP TODAY – THAT’S NOT THE KEY

THING. KEY THING HERE IS THAT WE HAVE APPLIED CARBON SUGAR. OKAY SO IF YOU

RECOGNIZE PENT YOU WOULD RECOGNIZE THE FIVE CARBONS. THIS PARTICULAR SUGAR DOES

HAVE, HOPEFULLY YOU COULD RECOGNIZE THAT GROUP UP THERE – THAT’S THE

GROUP. AND OF COURSE THE OH’S OVER HERE ARE THE ALCOHOL GROUPS THAT WE’VE CHM 105 & 106 MO1 UNIT SIX, LECTURE SIX 2

TALKED ABOUT PREVIOUSLY IN ORGANIC CHEMISTRY. NOW EVEN THOUGH WE CAN DRAW THE

MOLECULE IN A LINEAR FORM, AND EVEN THOUGH IT DOES EXIST OCCASIONALLY IN THE

LINEAR FORM – BY THAT I MEAN THE CARBONS ARE ALL HOOKED UP IN A LINE, MORE

FREQUENTLY IN NATURE WE FIND THE PENTOSE SUGARS, AND ACTUALLY WE’LL FIND THAT WE

FIND MOST OF THE SUGARS IN WHAT WE CALL A HETEROCYCLIC FORM RATHER THAN IN A

LINEAR FORM. NOW THAT’S NOT A NEW TERM TO US BECAUSE WE DID TALK ABOUT

HETEROCYCLIC WHEN WE TALKED ABOUT AMINES. THE TERM HETEROCYCLIC, OF COURSE

CYCLIC YOU COULD GUESS THAT MEANS THAT WE’RE GOING TO HOOK THINGS AROUND IN A

CYCLE, BUT THE TERM HETEROCYCLIC MEANS THAT ONE OF THE ATOMS IN THE RING IS A NON-

CARBON. OKAY HOMOCYCLIC WOULD BE SOMETHING LIKE THE BENZENE THAT WE TALKED

ABOUT IN THE PREVIOUS LECTURE. THE BENZENE WITH SIX CARBON RING STRUCTURE IS A

HOMOCYCLIC STRUCTURE. HETEROCYCLIC MEANS THAT ONE ATOM IN THE RING IS A NON-

CARBON. SO IF WE HAD SOMETHING LIKE WE HAD LOOKED AT EARLIER IN THE YEAR, WE

LOOKED AT SOMETHING LIKE THIS, WITH A HYDROGEN ON HERE AND A PAIR OF ELECTRONS,

AND WE CALLED THAT A HETEROCYCLIC AMINE. THAT WAS AN AMINE. THE NITROGEN-

HYDROGEN STRUCTURE IN THE OVERALL. THIS IS HETEROCYCLIC, AND AS I SAY IN MOST CASES

WE REALLY FIND THE PENTOSE SUGARS THEN NOT IN A LINEAR FORM IN NATURE BUT RATHER

IN THE HETEROCYCLIC FORM. SO LET’S TAKE A LOOK AT PENTOSE SUGAR THEN IN ITS

HETEROCYCLIC FORM. WE HAVE TWO TYPES OF PENTOSE SUGARS AND WE’RE GOING TO COME

BACK AND TALK ABOUT THESE EVEN FURTHER WHEN WE TALK ABOUT THE NUCLEIC ACIDS.

THIS IS CALLED THE SUGAR, AND ACTUALLY THE RIBOSE SUGAR IS EXACTLY WHAT WE

HAD JUST A MOMENT AGO IN THE LINEAR FORM EXCEPT THAT WE HAVE BENT IT AROUND AND

HOOKED IT TOGETHER IN THAT OXYGEN THAT WAS THERE ON THE ALDEHYDE GROUP AND

THEN WE STILL HAVE AN ALCOHOL, AN ALCOHOL, AN ALCOHOL, AND AN ALCOHOL. WE HAVE

FOUR ALCOHOLS LIKE WE DID PREVIOUSLY. THIS PARTICULAR FORM IS CALLED RIBOSE. THAT

LITTLE B IN FRONT OF IT IS A BETA RIBOSE BUT THAT’S NOT THAT ESSENTIAL TO US SO WE’LL

ONLY CONCENTRATE ON THE RIBOSE PART. OKAY RIBOSE, AND THEN THE NEXT ONE TO IT,

WHICH IS ALSO A PENTOSE SUGAR, IT STILL MEANS IT HAS TO HAVE FIVE CARBONS, AND THE CHM 105 & 106 MO1 UNIT SIX, LECTURE SIX 3

CARBONS IN THIS CASE THERE’S ONE CARBON THERE, EACH OF THESE CORNERS HERE ARE

ACTUALLY CARBONS. SO THAT’S WHERE OUR FIVE CARBONS ARE IN THAT STRUCTURE. AND

OVER HERE OF COURSE WE WOULD HAVE THE SAME THING. WE HAVE THESE FOUR CORNERS

ARE CARBONS AND OF COURSE NOW THE FIFTH ONE UP THERE. SO THEY’RE BOTH PENTOSE

SUGARS. RIBOSE, THIS IS CALLED , AND THE NAME DEOXYRIBOSE COMES FROM

THE FACT THAT IF YOU LOOK RIGHT HERE YOU NOTICE THAT THERE’S ONE LESS OXYGEN ON

THIS MOLECULE THAN THERE IS ON THIS MOLECULE. THERE’S ONE LESS ALCOHOL GROUP

ESSENTIALLY IN THE TWO. AND SO THE NAME DEOXY WHEN WE TALK ABOUT

DETOXIFICATION, MEANING TO REMOVE SOMETHING THAT’S TOXIC, DEOXY MEANS MINUS AN

OXYGEN AND SO THAT’S WHERE THE NAME COMES FROM. IT’S THE RIBO-SUGAR MINUS THE

ONE OXYGEN AND THAT MAKES IT DEOXYRIBOSE SUGAR. NOW THESE TWO AS I SAY ARE

IMPORTANT WHEN WE TALK ABOUT NUCLEIC ACIDS. THERE ARE TWO NUCLEIC ACIDS. DNA

AND RNA, AND RNA STANDS FOR RIBONUCLEIC ACID. AND THE R COMES FROM THIS PART

RIGHT HERE – RIBO-. DNA COMES FROM DEOXYRIBOSE, AND SO THAT’S WHERE

THE NAME DNA COMES FROM. DEOXYRIBOSE NUCLEIC ACID. NOW OF COURSE THIS IS JUST ONE

COMPONENT OF EACH OF THESE NUCLEIC ACIDS AND WE’LL LOOK AT THE NUCLEIC ACIDS IN

GRATER DETAIL LATER, BUT OUR STARTING BLOCK THEN, OUR SIMPLEST OF OUR SUGARS ARE

THEN THE PENTOSE SUGARS. NOW W E’LL GO UP ONE STEP AND WE’LL GO TO THE

SUGARS, MEANING THAT WE’RE NOW LOOKING AT SOMETHING THAT HAS SIX CARBONS. WE

HAVE SIX CARBONS – ONE, TWO, THREE, FOUR, FIVE, SIX CARBONS. NOTICE THAT EVERY ONE

OF THE CARBONS HAS AN ALCOHOL GROUP ON IT AND THE END GROUP UP HERE IS ONCE AGAIN

AN ALDEHYDE. AS A MATTER OF FACT THIS PARTICULAR SUGAR IS REFERRED TO AS AN ALDO-

HEXOSE. SO THE ALDO TELLS US THAT IT HAS AN ALDEHYDE GROUP ON IT AND THE HEX OF

COURSE SAYS THAT THERE’S SIX CARBONS THERE. SO THE NAME TELLS US WHAT THE

STRUCTURE IS. THE COMMON NAME FOR THIS ALDOHEXOSE IS . OR SOMETIMES IT’S

ALSO CALLED DEXTROSE. BOTH OF THOSE – THE DEXTROSE IS THE JUST VERY GENERIC

COMMON NAME, BUT GLUCOSE IS THE MORE COMMON NAME. SOMETIMES THIS IS ALSO

CALLED GRAPE SUGAR. THIS IS THE SUGAR THAT WE FIND IN GRAPES. THIS IS THE SUGAR THAT CHM 105 & 106 MO1 UNIT SIX, LECTURE SIX 4

IS GOING TO BE FERMENTED TO ETHYL ALCOHOL WHEN WE PRODUCE WINE. THIS IS THE

MATERIAL. REMEMBER WHEN WE LOOKED AT THE BEER AND WINE MAKING IN AN EARLIER

CHAPTER WE TALKED ABOUT THE FACT THAT IN BEER MAKING WE ARE STARTING WITH LIKE

STARCHES AND MUST CONVERT THEM TO SUGARS AND THEN FERMENT THEM. WHEN WE’RE

MAKING WINE WE’RE ALREADY STARING WITH A NATURAL SUGAR THAT’S THERE IN THE

GRAPE JUICE, AND ALL WE’RE DOING IS BRINING ABOUT THE FERMENTATION PROCESS. SO

ALDOHEXOSE AND ALDEHYDE SIX CARBONS AND THE GRAPE SUGAR. WE ALSO HAVE A

KETOHEXOSE. NOTICE HERE AGAIN WE STILL HAVE THE SIX CARBONS AND WE STILL HAVE

FIVE ALCOHOL GROUPS BUT NOTICE THIS TIME THIS CARBON-DOUBLE BOND-OXYGEN INSTEAD

OF BEING ON AN END CARBON WHICH IS TYPICAL OF THE ALDEHYDE IS ON A CARBON IN THE

RING, I MEAN IN THE CHAIN. AND SO THIS MAKES THIS THEN INSTEAD OF BEING AN ALDEHYDE

THIS TIME THIS IS A – AN R GROUP, AN R GROUP, AND THE C-DOUBLE BOND-O FOR THE

KETONE. SO THIS IS REFERRED TO AS A KETO-HEXOSE. AND AGAIN THE KETO TELLS US WE’RE

LOOKING FOR KETONE IN THE STRUCTURE – THE CARBON-DOUBLE BOND–OXYGEN IN THE RING,

OR IN THE CHAIN. AND HEX, THAT WE HAVE THE SIX CARBONS. THIS IS CALLED .

ALSO KNOWN AS LEVULOSE, BUT FRUCTOSE, AND IT’S FRUIT SUGAR. IT’S THE SUGAR THAT WE

FIND IN THE REST OF THE FRUITS. SO WE HAVE THE GRAPE SUGAR, IF WE CAN GET BOTH OF

THEM ON HERE FAIRLY CLOSE TO EACH OTHER. WE HAVE THE ONE THAT OCCURS IN GRAPES

WHICH IS THE ALDEHYDE, AND THE ONE THAT OCCURS IN MOST OF THE OTHER FOODS – APPLES,

PINEAPPLES, PEACHES, PEARS, WATERMELON, IS A FRUCTOSE. FRUIT SUGAR, AND IT’S A

KETONE STRUCTURE. THAT’S THE ONLY DIFFERENCE IN THE TWO. OKAY, ALRIGHT, ANY

QUESTIONS? NOW, LOOKING AT THE STRUCTURE THAT WE TYPICALLY FIND THEN, AGAIN THE

LINEAR IS NICE LOOKING AT TO SEE THE FUNCTIONAL GROUPS, BUT IN REALITY MOST OF THESE

STILL OCCUR IN NATURE IN A HETEROCYCLIC FORM. SO WE’RE GOING TO SHOW THESE NOW IN

THE HETEROCYCLIC FORM. THE ONE HERE IN THE MIDDLE IS THE FRUCTOSE, NOW THAT MEANS

THAT IT’S STILL A SIX CARBON. WE HAVEN’T LOST ANY CARBONS HERE AND WE SEE HERE’S A

CARBON, AND THERE’S A CARBON, AND THERE’S ONE, TWO, THREE, FOUR MORE CARBONS

RIGHT THERE THEN IN THE RING. BUT NOTICE THIS RING IN THE FRUCTOSE NOW HAS FIVE, IT’S A CHM 105 & 106 MO1 UNIT SIX, LECTURE SIX 5

FIVE MEMBER RING, WHEREAS IN THE TWO GLUCOSE MOLECULES WE HAVE A SIX MEMBER

RING. CARBON, CARBON, CARBON, CARBON, CARBON, AND THE OXYGEN, AND OF COURSE THE

SAME THING HERE. THE FIVE CARBONS IN THE RING AND ONE CA RBON OUTSIDE OF THE RING,

AND THE FRUCTOSE WE HAVE FOUR CARBONS IN THE RING AND TWO CARBONS OUTSIDE OF

THE RING. NOW THERE IS BECAUSE WHENEVER WE MAKE A RING, WHENEVER WE HAVE A

DOUBLE BOND WE TALKED ABOUT THE FACT THAT WE HAVE A RESTRICTIVE GEOMETRY, AND

WHEN THAT HAPPENS WE CAN HAVE GEOMETRIC ISOMERS, AND SO IF THINGS POINT UP OR

DOWN OFF OF A FIXED RING STRUCTURE THAT RING CAN’T TWIST. SO IF IT’S FIXED LIKE A PIE

PLATE, WHETHER WE HAVE SOMETHING STICKING UP FROM THE PIE PLATE OR DOWN FROM THE

PIE PLATE MAKES A DIFFERENCE – IT’S A DIFFERENT STRUCTURE. AND SO HERE WE SEE NOW

ON THE GLUCOSE OKAY. WE HAD THE TWO , THIS IS THE KETOHEXOSE – FRUCTOSE –

THIS IS THE ALDOHEXOSE WHICH IS THE GLUCOSE, BUT NOTICE WE’RE TALKING ABOUT AN

ALPHA FORM AND A BETA FORM. NOW THE DIFFERENCE BETWEEN THE ALOHA AND THE BETA

FORM WE CAN SEE HERE IS THAT AN ALPHA FROM THE OH ON THE NUMBER ONE CARBON –

THAT’S THIS ONE RIGHT HERE, IS BELOW THE RING. NOTICE THAT THE OH IS POINTING DOWN.

OVER HER EON THE BETA GLUCOSE THE OH IS POINTING UP. AND YOU MIGHT SAY WELL SO

WHAT? I MEAN BIG DEAL. SO ONE IS DOWN AND ONE IS UP RIGHT? WHAT POSSIBLE

DIFFERENCE COULD THAT MAKE TO ANYBODY? WELL WE’LL SEE IN A MINUTE THAT IT MAKES

QUITE A DIFFERENCE IN THE ADDITIONAL BIGGER SUGARS THAT WE MAKE WHETHER WE MAKE

THEM FROM AN ALPHA GLUCOSE SPECIES OR A BETA GLUCOSE SPECIES. WE GET TOTALLY

DIFFERENT MATERIALS PRODUCED. AND SO YES IN FACT IT BECOMES QUITE IMPORTANT TO US

AND TO UNDERSTANDING THE MORE COMPLEX CARBOHYDRATES. NOW, GLUCOSE IS

SOMETIMES REFERRED TO AS A DEDUCING SUGAR, AND THAT DOESN’T MEAN THAT WE LOSE

WEIGHT BY EATING IT. WHAT IT MEANS IS THAT IT HAS THE ABILITY TO CASE SOMETHING TO

BE REDUCED. WE TALKED ABOUT OXIDIZING AND REDUCING AGENTS IN CHAPTER 13. A

REDUCING AGENT WAS SOMETHING THAT CAUSED SOMETHING TO BE REDUCED AND ITSELF BE

OXIDIZED. SO A IS SOMETHING THAT WILL CAUSE SOMETHING IN THE

BIOLOGICAL SYSTEM TO BE REDUCED. FOR INSTANCE, IT MIGHT REDUCE IRON THREE TO IRON CHM 105 & 106 MO1 UNIT SIX, LECTURE SIX 6

TWO, OR IT MIGHT REDUCE VARIOUS OTHER METALLIC IONS THAT ARE PART OF OUR MINERAL

NEEDS. IT MIGHT REDUCE THEM FROM SAY A COPPER TWO TO A COPPER ONE. THINGS LIKE

THAT SO IT’S A REDUCING SUGAR. WHEN IT CAUSES SOMETHING TO BE REDUCED IT ITSELF

MUST BE OXIDIZED AND WE SEE WHAT HAPPENS UP HERE IS THIS ALDEHYDE GROUP BECOMES

OXIDIZED. NOTICE THAT WE ADDED AN OXYGEN ON HERE TO NOW THE ORGANIC ACID. THAT’S

A CARBOXYLIC ACID GROUP. SO IT HAS BEEN CHANGED THEN FROM AN ALDEHYDE TO AN

ORGANIC ACID BY CAUSING SOMETHING ELSE TO BE REDUCED IN THE BIOLOGICAL SYSTEM.

GLUCOSE ALSO CAN UNDERGO OXIDATION AND HERE A CASE WHERE IT UNDERGOES

OXIDATION. SO HERE WE SEE NOW THAT WE AGAIN START WITH THE ALDEHYDE ON THE

GLUCOSE AND THIS TIME WE’RE GOING TO ADD A HYDROGEN HERE. SO WE’RE BREAKING THAT

BOND AND PUTTING A HYDROGEN ON AND CONVERTING IT UP TO AN ALCOHOL. THIS

PARTICULAR SUBSTANCE HERE WITH SIX ALCOHOL GROUPS, NO ALDEHYDE OR KETONE, HAS A

COMMERCIAL NAME CALLED SORBITOL. THIS IS A FAIRLY GOOD SUGAR SUBSTITUTE. IT HAS

ABOUT 70% THE SWEETNESS OF TABLE SUGAR, BUT ONE OF THE ADVANTAGES IS THAT WHEN

THE BIOLOGICAL SYSTEM PROCESSES IT THAT WE DON’T END UP FORMING THE NORMAL

SUGARS THAT WE DO. MOST OF IT IS CONVERTED TO CARBON DIOXIDE AND WATER AND IT CAN

BE USED BY PERSONS THAT HAVE A CONCERN ABOUT DIABETES. IT’S NOT A NON-CALORIC. IT’S

JUST A SUGAR SUBSTITUTE. BIOLOGICALLY IT GOES THROUGH A DIFFERENT PROCESS, ONE

THAT UNDERGOES THEN THE CHANGE TO CO2 AND WATER, WHICH ALLOWS IT TO BE USED THEN

AS A SWEETENER BY PEOPLE THAT HAVE A PROBLEM WITH DIABETES. SO AGAIN THE

BEING CONVERTED TO THIS, THIS IS USED A SA SWEETENER IN CANDIES, USED AS SWEETENER

IN GUM MATERIALS. SO IT’S A FAIRLY COMMON SWEETENER OVERALL. NOW, THAT’S THE

SIMPLEST SUGAR. NOW WE’RE GOING TO GO TO THE NEXT BIGGER GROUP AND WE’RE GOING

TO GO THEN TO NOW WHAT WE CALL THE . WELL WE ALL KNOW WHAT THE

PREFIX DI MEANS. OF COURSE IT MEANS THAT THERE ARE TWO. SO WE’RE GONNA TAKE TWO

OF THOSE GROUPS THAT WE JUST TALKED ABOUT LIKE A GLUCOSE AND A

FRUCTOSE OR A GLUCOSE AND A GLUCOSE – WHATEVER THE CASE MAY BE, AND WE’RE GONNA

HOOK TWO OF THEM TOGETHER AND WE’RE GOING TO MAKE A . ACTUALLY I CHM 105 & 106 MO1 UNIT SIX, LECTURE SIX 7

SHOULD HAVE MENTIONED THAT ON THE MONOSACCHARIDES OF COURSE WE DO HAVE THE

GLUCOSE. WE HAVE THE FRUCTOSE, AND THEN ONE THAT I DIDN’T MENTION WAS I’LL JUST PUT

IT UP HERE IN THE CORNER, ONE OTHER MONOSACCHARIDE IS CALLED . AND WE’LL

RUN INTO THAT HERE AGAIN BUT THAT’S THE THIRD MONOSACCHARIDE THAT WE TYPICALLY

TALK ABOUT. GLUCOSE, FRUCTOSE, GALACTOSE. OKAY, NOW IF WE TAKE A GLUCOSE AND A

FRUCTOSE, TWO MONOSACCHARIDES, TWO SEPARATE MOLECULES AND IF WE REACH IN HERE

AND PULL OUT A MOLECULE OF WATER WE DEHYDRATE THE SUGAR. AND IF WE DO THAT

WHAT WE END UP WITH NOW IS THIS STRUCTURE RIGHT HERE, NOTICE THIS IS THE BRIDGING

OXYGEN. WHEN WE PULL THESE OFF IT’S GOING TO BE HOOKED FROM HERE TO THAT OXYGEN,

AND THIS IS SUCROSE. SO THE COMBINATION OF A GLUCOSE WITH A FRUCTOSE GIVES US

SUCROSE, AND THIS IS OUR NORMAL TABLE SUGAR. NOW WE’LL TALK A LITTLE BIT ABOUT THE

DIGESTION OF CARBOHYDRATES IN JUST A LITTLE BIT BUT OUR BODY CAN ONLY ABSORB

MONOSACCHARIDES, AS FAR AS PUTTING THEN ENERGY INTO THE BLOODSTREAM THAT CAN BE

TAKEN TO CELLS AND USED IT HAS TO BE IN THE FORM OF A MONOSACCHARIDE. SO IF ER EAT

TABLE SUGAR, BEFORE WE CAN USE THAT TABLE SUGAR IT HAS TO BE REHYDRATED, THE

PROCESS HAS TO BE REVERSED AND THE SUCROSE HAS TO BE CONVERTED BACK TO THE

FRUCTOSE AND GLUCOSE. ONCE IT’S CONVERTED BACK TO THAT THEN IT CAN BE ABSORBED

INTO THE BLOODSTREAM AND TRANSPORTED AND USED FOR ENERGY. NOW, HONEY, NATURAL

OCCURRING SWEETENER, BUT HONEY IS ABOUT A 50/50 MIXTURE OF GLUCOSE AND FRUCTOSE.

NOW BEES HAVE AN ENZYME IN THEIR SYSTEM THAT ALLOWS THEM TO TAKE SUCROSE, THEY

GO OUT TO THE FLOWERS AND PICK UP THE LIQUID FROM THE FLOWERS WHICH CONTAINS THE

SUGAR, AND PART OF THE SUGAR THAT THEY DON’T USE – THE EXCESS SUGAR, IS

AUTOMATICALLY BROKEN DOWN INTO THESE TWO AND STORED AS HONEY, WHICH IS THEN

THIS MIXTURE HERE. SO IF YOU WANT QUICK ENERGY THEN EATING A CANDY BAR IS GOING TO

BE A SLOW PROCESS BECAUSE YOU HAVE TO DIGEST THIS FIRST. BUT IF YOU WANT QUICKER

ENERGY, IF YOU EAT HONEY, OR HONEY CONTAINING SWEETENED PRODUCTS, THEY’RE

ALREADY READY TO BE ABSORBED INTO THE BLOODSTREAM. SO THE DIGESTIVE PROCESS

DOESN’T HAVE TO OCCUR. ALRIGHT, GLUCOSE AND FRUCTOSE WILL GIVE US SUCROSE OR CHM 105 & 106 MO1 UNIT SIX, LECTURE SIX 8

TABLE SUGAR. ANOTHER COMBINATION IS A GLUCOSE PLUS A GLUCOSE. AN ALPHA GLUCOSE

PLUS AN ALPHA GLUCOSE GIVES US A SUGAR, A DISACCHARIDE CALLED . NOW

MALTOSE IS A SUGAR THAT WE TALKED ABOUT EARLIER IN THE COURSE WHEN WE AGAIN

TALKED ABOUT THE BEER BREWING INDUSTRY. MALT., WHICH IS A PART OF THE BREWING

PROCESS, MALT CONTAINS MALTOSE. MALTOSE IS THE FIRST SUGAR THAT WE’RE USING IN THE

BEER BREWING INDUSTRY WHICH WILL FINALLY BE BROKEN BACK DOWN INTO GLUCOSE AND

THEN ONCE IT’S IN THE FORM OF GLUCOSE IT WILL BEGIN UNDERGOING THE FERMENTATION

PROCESS TO ETHYL ALCOHOL. SO THIS IS MALT SUGAR, OR SOMETIMES REFERRED TO AS GRAIN

SUGAR BECAUSE IT’S OBTAINED WHEN WE GERMINATE THE BARLEY AND THEN WE TAKE THE

GERMINATED SEED AND THEN DRY IT. WE WILL HAVE THIS MALT SUGAR, AND SO THIS IS

SOMETIMES REFERRED TO AS GRAIN SUGAR. OKAY, AND THE GRAIN SUGAR THEN IS AS I SAY

WHAT IS USED TO START THE BREWING PROCESS OR ALSO IS USED AS A SWEETENER IN MALTED

MILKS. OKAY, SO WHEN WE TALK ABOUT A MALTED MILK WE’RE TAKING THE MILK AND THE

ICE CREAM AND THE FLAVORING AND THEN WE ADD THIS WHICH MAKES IT SLIGHTLY SWEETER

DUE TO THE PRESENCE OF THE MALT. ANOTHER COMBINATION AND THIS ONE I DON’T HAVE

DRAWN OUT, BUT IF WE TAKE A GLUCOSE AND A GALACTOSE WE PRODUCE ANOTHER

DISACCHARIDE CALLED . AND LACTOSE IS KNOWN AS MILK SUGAR. OKAY THIS IS THE

SUGAR THAT WE DO FIND IN MILK WHICH OF COURSE IS ONE OF THE MAJOR ENERGY

INGREDIENTS FOR BABIES, FOR YOUNGSTERS, FOR YOUNG ANIMALS, AND A VERY HIGH LEVEL

OF LACTOSE WHICH IS USED BY THE BODY TO PROVIDE THE SUGAR CONTENT. SOW E HAD

THREE MONOSACCHARIDES. WE HAD THE GLUCOSE, FRUCTOSE AND GALACTOSE, AND IF WE

HOOKED DIFFERENT COMBINATIONS OF THESE TOGETHER WE CAN PRODUCE VARIOUS TYPES

OF DISACCHARIDES. THREE THAT WE’VE LISTED HERE THEN THE FIRST ONE SUCROSE OR TABLE

SUGAR. MALTOSE OR GRAIN SUGAR, AND LACTOSE – MILK SUGAR. IN THE TEXT IS A TABLE

THAT SHOWS THE COMBINATION THEN IN THE DIFFERENT TYPES OF DISACCHARIDES THAT ONE

GETS. NOW WHEN WE THINK OF SUGARS WE THINK OF OF COURSE SWEETNESS, AND THIS GIVES

A TABLE OF THE VALUES OF THE CONTRAST IN SWEETNESS OF THE VARIOUS CARBOHYDRATES.

HERE IS SUCROSE – TABLE SUGAR. IT IS ARBITRARILY SET AS THE SWEETNESS OF ONE. IN CHM 105 & 106 MO1 UNIT SIX, LECTURE SIX 9

OTHER WORDS THERE IS NO WAY TO MEASURE THIS DIRECTLY OTHER THAN BY TASTE AND SO

THE SWEETNESS IS IN TERMS OF PALATABILITY TEST. AND SO SUGAR, TABLE SUGAR IS

CONSIDERED ONE. WE SEE THAT FRUCTOSE OR FRUIT SUGAR, THIS IS A MONOSACCHARIDE. SO

LET’S IDENTIFY THE ONES HERE THAT ARE THE SUCROSE, IS A DISACCHARIDE. FRUCTOSE IS

MONOSACCHARIDE. GLUCOSE MONO. GALACTOSE MONO, AND THEN DI AND DI SACCHARIDE.

ALRIGHT, SO WE SEE THAT THE SWEETEST SUGAR THAT WE HAD, THE SWEETEST

CARBOHYDRATE THAT WE HAVE IS FRUIT SUGAR OR FRUCTOSE. GLUCOSE, .74. GALACTOSE

ABOUT THE SAME AS MALTOSE. SO THE MALT SUGAR AND GALACTOSE ARE ABOUT THE SAME,

AND FINALLY THE MILK SUGAR IS NOT VERY SWEET AT ALL. YOU DON’T DETECT ANY

SWEETNESS WHEN YOU DRINK MILK EVEN THOUGH THERE IS THAT IN THERE

THAT WOULD HAVE SOME SWEETNESS IN IT. IT’S PRETTY LOW SWEETNESS WHEN WE COMPARE

IT TO TABLE SUGAR. ALRIGHT, NOW THE LAST THREE ARE ARTIFICIAL SWEETENERS.

CYCLAMATE, ABOUT THREE TIMES SWEETER THAN TABLE SUGAR, AND THEN NUTRASWEET OR

ASPARTAME AND SACCHARINE. SACCHARINE WAS THE FIRST OF THE ARTIFICIAL SWEETENERS

THAT WERE PRODUCED. AND AS I MENTIONED THE NAME SACCHARINE OF COURSE COMES

FROM THE NAME SACCHARIDE AND IS A TERM USED FOR SUGARS. SACCHARINE – EXTREMELY

SWEET AND IT WAS DEVELOPED PRIMARILY IN WORLD WAR TWO WHEN SUGAR SUPPLIES WERE

SHORT AND WHAT SUGAR WE DID HAVE WENT TO THE WAR EFFORTS AND SO PEOPLE STILL

WANTED SWEETENER FOR THEIR CEREAL AND THINGS LIKE THAT AND SO SOMEBODY SET OUT

AND FORMED THE SACCHARINE. AND NOTICE THE SWEETNESS. OBVIOUSLY YOU CAN’T PUT A

TEASPOON OF SACCHARINE ON YOUR CEREAL. AS A MATTER OF FACT IT WAS SOLD ORIGINALLY

AS A LIQUID, A VERY VERY DILUTE LIQUID AND YOU PUT IT ON AS A DROP. SO IF YOU HAD A

BOWL OF CEREAL YOU’D TAKE A DROP OF SACCHARINE AND PUT INTO YOUR BOWL OF CEREAL

FOR THE SWEETNESS. THE ONE PROBLEM WITH THE SACCHARINE WAS THAT IT DOES LEAVE

SORT OF A BITTER AFTERTASTE AND SO FROM THAT STANDPOINT IT WAS NOT TOO POPULAR

AND SO THEREFORE IN THE 50’S THEY SET OUT TO FIND A DIFFERENT SWEETENER AND THIS ONE

HAPPENED TO BE CYCLAMATE, AND IT’S NOT AS SWEET. AS A MATTER OF FACT IT’S A

HUNDRED TIMES LESS SWEET BUT IT’S STILL THREE TIMES SWEETER THAN TABLE SUGAR. SO CHM 105 & 106 MO1 UNIT SIX, LECTURE SIX 10

YOU’D HAVE TO USE A FAIR AMOUNT BUT YOU DIDN’T HAVE TO CUT WAY BACK LIKE YOU DID

WITH THE SACCHARINE. SOMEBODY DID A STUDY IN CANADA ON RATS AND FOUND THAT IF

YOU FED A RAT 100 POUNDS OF CYCLAMATE A DAY THAT IT DIED FROM CANCER. WELL YOU

PROBABLY FEED IT A HUNDRED POUNDS A DAY OF ANYTHING AND IT WOULD PROBABLY DIE OF

SOMETHING. BUT THE STUDY THEN LED TO SOME CONCERN THAT CYCLAMATES WHICH WERE

BEING USED EXTENSIVELY IN DIETARY DRINKS AND ARTIFICIAL SWEETENERS AND LOW SUGAR

CANDY, LOW CALORIE CANDY, THINGS LIKE THAT. SO THE FEDERAL GOVERNMENT RULES

THAT CYCLAMATES COULD NOT BE USED FOR HUMAN CONSUMPTION AND BASED ON CANADA

STUDY, THERE WAS A LOT OF DEBATE ON WHETHER THE STUDY WAS VALID AND CAN WE TEST

WITH THIS MAGNITUDE OF CHEMICAL TO REALLY DETERMINE TOXICITY BUT THEY MADE A

MOVE THAT WE COULDN’T USE IT ANY MORE BUT THEY REALLY WEREN’T AS WORRIED ABOUT

US AS WE MIGHT HAVE THOUGHT BECAUSE SOMEBODY HAD ALREADY DISCOVERED

ASPARTAME WHICH IS 200 TIMES A SWEET AS SUGAR AND DOESN’T HAVE THE BITTER

AFTERTASTE OF SACCHARINE AND DIDN’T HAVE ANY APPARENT HEALTH PROBLEMS. AND SO

CYCLAMATE WAS REMOVED FROM THE MARKET AND OF COURSE MOST OF THE SWEETENING

TODAY WE SEE IS, ARTIFICIAL SWEETENING, IS DONE WITH NUTRASWEET. HOWEVER, LATER

STUDY TOOK AWAY THE VILLAIN PART OF THE CYCLAMATE AND SO YOU WILL SEE NOW

CYCLAMATES ONCE AGAIN BEING USED AS SWEETENERS, AND BECAUSE OF THE BITER

AFTERTASTE HERE, BY USING A VERY SMALL AMOUNT OF THIS WITH CYCLAMATE YOU CAN

GET THEN A FAIR SWEETENING WITH A RELATIVELY SMALL AMOUNT AND GET RID OF THE

BITTER AFTERTASTE PRIMARILY. AND SO THE COMBINATION OF THE CYCLAMATE,

SACCHA RINE IS ONE OF THE THINGS THAT’S USED FOR SWEETENERS. THE OTHER MAJOR

ARTIFICIAL SWEETENER IS OF COURSE THE NUTRASWEET. BUT AGAIN THE SWEETEST OF ALL

OF THE NATURAL SUGARS IS THE FRUCTOSE. NOW, THE NEXT GROUP OF CARBOHYDRATES, IF

WE STARTED AT MONO AND THEN WE WENT TO TRI BUT WE’RE GOING TO JUMP FURTHER THAN

THAT. WE’RE GOING TO GO TO POLY. POLY MEANS MANY SACCHARIDES. OKAY, SO LET’S TAKE

A LOOK AT SOME POLY SACCHARIDES. WHOOPS. NOW THE POLY SACCHARIDES MEAN THAT WE

HAVE MANY OF THESE SINGLE UNITS HOOKED TOGETHER AND THEY’RE ALL DONE BY CHM 105 & 106 MO1 UNIT SIX, LECTURE SIX 11

DEHYDRATING, BY PULLING THE WATER MOLECULE OUT FROM BETWEEN THE MONO GROUPS

AS WE GO ALONG. IF WE GO BACK, LET ME DO THAT I GUESS QUICKLY WITH THE

DISACCHARIDE HERE, NOTICE THAT WHEN WE PULL OUT A WATER HERE AND HOOK IT

TOGETHER HERE NOTICE WE STILL HAVE AN OH GROUP HERE, AN OH GROUP HERE, JUST LIKE

WE HAD THERE IN THE MONOSACCHARIDE. AND SO THOSE ARE H GROUPS ARE STILL

AVAILABLE TO ATTACH TO ANOTHER ONE ON THIS END AND ANOTHER ONE ON THAT END. AND

SO WE CAN PROPAGATE THIS INTO A , A LARGE THEN MOLECULE. THIS IS WHERE

THAT LITTLE DIFFERENCE BETWEEN THE ALPHA GLUCOSE, REMEMBER THE OH POINTING UP

AND THE BETA GLUCOSE – THE OH, POINTING DOWN ON THE RING ON THAT FIRST CARBON?

TURNS OUT TO BE QUITE IMPORTANT. IF WE HOOK TOGETHER ALPHA GLUCOSE STRINGS – SO

THIS IS A MONOSACCHARIDE AND THERE’S ONE HOOKED UP AND THEN THE NEXT ONE HOOKED

UP AND THE NEXT ONE AND NEXT ONE ET CETERA, AND THIS PRODUCES WHAT WE CALL

AMYLOSE, AND THIS IS A TYPE OF WHAT WE REFER TO IN GENERA L AS .

ANOTHER FORM OF STARCH OCCURS WHEN OCCASIONALLY INSTEAD OF EVERYTHING HOOKING

TOGETHER IN A CONTINUOUS STRAIGHT LINE OCCASIONALLY WE GET ONE FROM A CARBON-

ONE HOOKING TO A CARBON SIX STRUCTURE. THAT’S CALLED THE ONE-SIX LINKAGE, NOT

THAT YOU NEED TO WORRY ABOUT THAT. WELL WHEN WE DO THAT WE MAKE ANOTHER

STARCH CALLED . IF YOU’VE EVER HEARD OF FROM FRUITS. WE USE

PECTIN TO MAKE JELLIES. WE’RE ADDING THIS PARTICULAR TYPE OF STARCH WHICH THEN IN

THE COOKING PROCESS AND WHEN IT COOLS HELPS FORM A SEMI-SOLID MASS SO OUR JELLY

SETS UP. SO IT’S NOT LIKE SYRUP BUT IT BECOMES LIKE A SEMI-SOLID. THIS IS THE PECTIN

THAT WE TALK ABOUT, THE AMYLOPECTIN HERE. NOW THESE ARE THE TWO COMMON

STARCHES AND THEY’RE MADE FROM, BOTH ARE MADE FROM THAT ALPHA GLUCOSE, THAT’S

THE IMPORTANT PART HERE, THE ALPHA GLUCOSE. OUR BODY, IF WE EAT A LOT OF SUGAR, A

LOT OF DISACCHARIDES FOR INSTANCE AND WE DON’T NEED ALL OF THAT FOR THE ENERGY

OUR BODY TAKES THOSE DISACCHARIDES AND BEGINS HOOKING THEM TOGETHER AND HOOKS

THEM TOGETHER IN THE FORM OF A STARCH AMYLOPECTIN. IN THE BODY WE REFER TO THIS

AS . THIS IS THE TERM THAT IS USED FOR THE STORED STARCHES OR THE STORED CHM 105 & 106 MO1 UNIT SIX, LECTURE SIX 12

CARBOHYDRATES IN OUR BODY ARE REFERRED TO AS GLYCOGEN. AND GLYCOGEN IS MERELY

AMYLOPECTIN, WHICH IS JUST OUR BODY PUTTING TOGETHER ALL OF THOSE MONO AND

DISACCHARIDES THAT WE DON’T NEED AND STORING THEM SOMEPLACE AS THEN THE STARCH,

STORED MATERIAL GLYCOGEN. AND THEN OF COURSE WHEN WE BECOME MORE ACTIVE AND

THE BODY DEMANDS MORE SUGAR THEN THE BODY REHYDRATES THESE, STARTS CLIPPING OFF

LITTLE PIECES OF IT AND PUTS THE MONOSACCHARIDES BACK INTO THE BLOODSTREAM SO IT

CAN BE USED TO PROVIDE US THE ENERGY WE NEED. SO WE STORE, WE STORE THE EXCESS

SUGAR IN OUR BODIES IN THE FORM OF GLYCOGEN. NOW, IF IN CONTRAST, WELL LET ME

JUST…I’LL PUT THIS UP. THIS JUST GIVES ANOTHER LITTLE PICTURE OF THE TWO. THIS IS THE

AMYLOSE, IT JUST KIND OF MAKES UP A CHAIN LIKE HOOKING PAPER CLIPS TOGETHER TO

MAKE THIS BIG MOLECULE AND THEN THE AMYLOPECTIN WHICH IS A BRANCH. SO EVERY ONCE

IN A WHILE WE HOOK ANOTHER SET OF PAPER CLIPS GOING OFF IN A DIFFERENT DIRECTION

AND SO WE GET THIS BRANCH AND THIS IS THE AMYLOPECTIN THEN OR GLYCOGEN THAT OUR

BODY STORES THE EXCESS SUGARS. NOW IF IN CONTRAST ONCE AGAIN REMEMBER ALPHA HAD

THE OH UP, BETA HAS THE OH DOWN. IF WE TAKE BETA GLUCOSE AND HOOK IT TOGETHER,

INSTEAD OF MAKING A LINE WITH THE OXYGEN DOWN AT THAT V LIKE IT DID IN THE STARCHES

NOTICE THAT THE OXYGEN NOW IS HOOKED THIS WAY, UPWARD, UPWARD, UPWARD, AND SO

WE END UP WITH A STAIR-STEP -LOOKING MOLECULE AND THIS IS . BOTH OF THESE

ARE MADE FROM MONOSACCHARIDES – STARCH AND CELLULOSE. THE ONLY DIFFERENCE IS

THE STARCHES ARE MADE FROM THE ALPHA GLUCOSE AND THE CELLULOSE IS MADE FROM THE

BETA GLUCOSE. NOW GAIN OF WHAT IMPORTANCE IS THAT TO US? WELL THE FACT IS IN OUR

DIGESTIVE SYSTEM WE DON’T HAVE ANY ENZYMES IN OUR DIGESTIVE SYSTEM THAT ALLOW US

TO BREAK CELLULOSE DOWN. SO IF I EAT FOODS CONTAINING CELLULOSE – WHICH IS

BASICALLY JUST ANOTHER MODIFIED FORM OF STARCH, A , IF I EAT

CELLULOSE IT DOES NOTHING. IT GOES RIGHT ON THROUGH THE BODY – IT’S FLUSHED OUT –

IT’S WASTE. WE CANNOT USE IT FOR ENERGY. NOW THERE ARE SOME ORGANISMS THAT CAN.

FOR INSTANCE TERMITES WHICH HAVE ASSOCIATED WITH THEM BACTERIA THAT DOES HAVE

AN ENZYME THAT CAN BREAK THIS DOWN SO THE TERMITE GOES OUT AND CHEWS UP THE CHM 105 & 106 MO1 UNIT SIX, LECTURE SIX 13

WOOD AND THEN THE BACTERIA PROVIDES THE ENZYME TO BREAK IT DOWN AND SO BOTH THE

MICROORGANISM AND ALSO THE TERMITE CAN USE THEN THE MONOSACCHARIDES PRODUCED

IN THE PROCESS TO LIVE ON. BUT MOST ANIMALS, HUMANS, CANNOT PROCESS CELLULOSE. WE

DON’T HAVE THE ENZYME NECESSARY FOR IT. SO THERE’S QUITE A DIFFERENCE WHETHER WE

TAKE AN ALPHA OR A BETA GLUCOSE AND HOOK THEM TOGETHER TO MAKE OUT

POLYSACCHARIDES. OF COURSE HERE’S AN EXAMPLE OF A COUPLE OF PLACES THAT WE HAVE

A GOOD SUPPLY OF OF COURSE THE POTATO OR THE EDIBLE STARCH, AND

CABBAGE. CABBAGE HAS BOTH A FAIRLY HIGH AMOUNT OF CARBOHYDRATE AND ALSO

CELLULOSE BY THE WAY. BUT IT TURNS OUT THAT WE DO LIKE TO HAVE SOME CELLULOSE IN

OUR DIET BECAUSE WE CALL IT ROUGHAGE AND IT HELPS THE DIGESTIVE TRACT, STIMULATES

THE DIGESTIVE TRACT, AND SO IT IS NOT BAD ONCE IN AWHILE TO EAT A PENCIL JUST TO

KIND OF STIMULATE THINGS A LITTLE BIT. OKAY, OF COURSE THE MAJOR PLACE THAT

CELLULOSE IS FOUND IN NATURE OF COURSE IS IN PLANTS WHERE IT IS THE STRUCTURAL

MATERIAL. IT’S THE MATERIAL THAT GIVES THE TREE IT’S SUPPORT. THE LEAF IT’S

STRUCTURE. IT’S THE CELLULOSE. SO IT LOOKS LIKE BASICALLY STARCH BUT BECAUSE OF ITS

STRUCTURE IT’S VERY RIGID AND CAN PROVIDE THEN CONSIDERABLE SUPPORT. I MEAN THE

SUPPORT THAT A TREE BRANCH CAN SUPPORT IS RELATIVELY AMAZING, AND IT’S JUST THESE

FIBERS OF CELLULOSE THAT ARE THEN HYDROGEN BONDED TOGETHER THAT MAKE UP THESE

GIANT STRANDS THAT HOLD BASICALLY THOSE OR MAKE THE STRUCTURE FOR THOSE PLANTS.

ALRIGHT, NOW A LITTLE BIT ABOUT DIGESTION QUICKLY AND WHAT HAPPENS WHEN WE EAT

SOMETHING. AND LET’S START WITH A POLYSACCHARIDE BECAUSE USUALLY A GOOD SHARE

OF WHAT WE EAT IS STARCH. IN THE MOUTH WE HAVE AN ENZYME WHICH WILL BEGIN THE

CONVERSION OF THE POLYSACCHARIDES NOW TO MALTOSE. IN OTHER WORDS WE’RE GONNA

TAKE THE BIG MOLECULE AND CLIP IT INTO A DISACCHARIDE – MALTOSE IS A DISACCHARIDE.

NOW YOU CAN KIND OF DEMONSTRATE THIS YOURSELF IF YOU TAKE AN UNSALTED CRACKER

OR UNSALTED BREAD AND PUT IT IN YOU MOUTH AND CHEW IT OR JUST LET IT SLOSH AROUND

AND THEN TASTE IT AND YOU’LL NOTICE A SWEETNESS. THE SWEETNESS IS DUE TO THE FACT

THAT THE ENZYME IN THE MOUTH HAS BEGUN THE CONVERSION TO THE MALT SUGAR AND SO CHM 105 & 106 MO1 UNIT SIX, LECTURE SIX 14

WHAT YOU’RE DETECTING THEN IS MALTOSE. NOW KEEP IN MIND IT’S ONLY ABOUT 30% AS

SWEET AS TABLE SUGAR SO YOU’RE NOT GOING TO GET A REAL LARGE ABUNDANCE OF

SWEETNESS BUT YOU’LL NOTICE A DEFINITE SWEET TASTE IF IN FACT YOU HAVE AN UNSALTED

SOURCE OF STARCH IN YOUR MOUTH. AS FAR AS THE CARBOHYDRATES ARE CONCERNED THE

STOMACH DOESN’T DO ANYTHING. THERE’S NO DIGESTION OF CARBOHYDRATES IN THE

STOMACH SO IT HAS TO GET THROUGH THE STOMACH BEFORE WE REALLY GET TO HAVE ANY

ADVANTAGE OF THE STARCHES AND THINGS LIKE THAT THAT WE EAT. ONCE IT MOVES INTO

THE SMALL INTESTINE THEN WE’RE GOING TO FIND A WHOLE SERIES OF THINGS BEGIN TO

OCCUR. FIRST OF ALL AND WE TALKED ABOUT ENZYMES IN THE CHAPTER ON THINGS THAT

AFFECT REACTION RATES, BUT IN THE BIOLOGICAL SYSTEM REMEMBER THAT EACH ONE OF

THESE CATALYSTS, EACH ONE OF THESE BIOCHEMICAL CATALYSTS IS REFERRED TO AS AN

ENZYME AND EACH ENZYME HAS A NAME AND IT ENDS IN ASE, AND IT USUALLY REFERS TO

WHAT IT’S DOING. OKAY, SO FERRO-OXIDASE WAS ONE I THINK WE LOOKED AT ONE DAY. THAT

WAS SOMETHING THAT CATALYZED THE FORMATION OF THE IRON-II IN THE HEME. OKAY SO

THE NAME. NOW HERE WE SEE THEN WE START STARCH REACHES THE SMALL INTESTINE. WE

HAVE AN AMYLASE, OKAY, THAT MEANS AN ENZYME THAT IS GOING TO BREAK UP, GOING TO

CHOP UP AMYLOSE. REMEMBER AMYLOSE IS THE NAME FOR THE POLYSACCHARIDE STARCH

MOLECULE AND IT’S GOING TO BREAK IT UP INTO UNITS OF MALTOSE. AS THE MALTOSE

CONTINUES TO MOVE THROUGH THE SMALL INTESTINE ANOTHER ENZYME COMES INTO PLAY

AND MALTOSE IN THE PRESENCE OF MALTASE BECOMES CUT INTO AN PRODUCES THE TWO

GLUCOSE MOLECULES. NOW AS SOON AS THE GLUCOSE IS FORMED THEN IT IS NOW READY TO

BE ABSORBED INTO THE BLOODSTREAM THROUGH THE WALLS OF THE INTESTINE WHERE THE,

WHICH ARE VERY RICH IN BLOOD VESSELS. SO AT THIS POINT THE GLUCOSE CAN MOVE INTO

THE BLOODSTREAM AND BEGIN BEING CIRCULATED TO THE BODY. NOW AS I MENTIONED IF I

TAKE SOME TABLE SUGAR AND EAT IT IT HAS TO PASS THROUGH THE MOUTH, THROUGH THE

STOMACH INTO THE SMALL INTESTINE AND GET TO THE POINT WHERE IT RUNS INTO THIS

ENZYME CALLED SUCRASE BEFORE IT’S BROKEN DOWN INTO GLUCOSE AND FRUCTOSE WHICH

CAN BE ABSORBED INTO THE BLOODSTREAM. IF I EAT FRUCTOSE OR HONEY WHICH IS A CHM 105 & 106 MO1 UNIT SIX, LECTURE SIX 15

MIXTURE OF THESE TWO, IF I EAT HONEY DIRECTLY OR EAT AN APPLE OR A PEACH OR PEAR,

SOMETHING THAT WILL GIVE ME THE FRUCTOSE THEN THAT IS ALREADY READY TO GO INTO

THE BLOODSTREAM AS SOON AS IT PASSES THROUGH THE STOMACH. STILL HAS TO GET OUT OF

THE STOMACH. I MEAN SO WE DON’T GET AN INSTANT. IF WE EAT SOMETHING IT’S STILL GOING

TO GET THROUGH THE STOMACH BEFORE IT CAN BE ABSORBED INTO THE BLOODSTREAM AND

THEN WE GET OUR ENERGY, BUT WE DON’T NEED TO WAIT FOR THIS PROCESS TO OCCUR

BECAUSE IT’S ALREADY IN THIS FORM IF WE EAT HONEY. ALRIGHT, THE SUCROSE UNDERGOES

BREAKDOWN AND THE LACTOSE OR MILK SUGAR UNDERGOES BREAKDOWN IN THE PRESENCE

OF THIS ENZYME CALLED LACTASE. NOW AS WHEN WE’RE BORN WE HAVE A VERY HIGH LEVEL

OF LACTASE, AND OF COURSE THAT’S NECESSARY TO BREAK DOWN THE MILK SUGAR BECAUSE

MILK IS A PART OF OUR DIET. AS WE MATURE OUR BODY DECREASES THE AMOUNT OF LACTASE

IT PRODUCES, AND IN SOME CASES AS ADULTS, CERTAIN PEOPLE WILL GET TO THE POINT THAT

THEY’LL HAVE NO LACTASE AND THEREFORE IF THEY EAT MILK PRODUCTS – PIZZA, ICE CREAM,

ALL OF THOSE GOOD THINGS, THE LACTOSE THAT’S THERE FROM THE MILK PRODUCTS CANNOT

BE DIGESTED AND THE LACTOSE WILL PASS INTO THE LARGE INTESTINE AS LACTOSE

MOLECULES. THERE ARE BACTERIA IN THE LARGE INTESTINE HOWEVER THAT WILL BEGIN TO

FERMENT THE LACTOSE, THUS CAUSING TREMENDOUS AMOUNTS OF GAS BEING PRODUCED,

STOMACH CRAMPS. DIARRHEA CAN BE SERIOUS PROBLEMS, AND WE REFER TO PEOPLE THAT

HAVE THAT CONDITION AS BEING LACTOSE INTOLERANT, AND OF COURSE FORTUNATELY, AND

I THINK I MENTIONED THIS WHEN WE TALKED ABOUT THE ENZYMES AND THE CATALYSTS,

FORTUNATELY WE'VE BEEN ABLE TO SYNTHESIZE THIS SO THAT PEOPLE WITH BIOLOGICAL

LACTOSE INTOLERANCE CAN TAKE A LACTASE TABLET WITH THEIR ICE CREAM CONE OR WITH

THEIR PIZZA OR WITH THEIR CHEESE SANDWICH AND THAT WILL PROVIDE THE ENZYME TO BE

ABLE TO BREAK THAT LACTOSE DOWN INTO GLUCOSE AND GALACTOSE SO IT CAN BE TAKEN

INTO THE BLOODSTREAM AND NOT HAVE THE FERMENTATION PROCESS. ALRIGHT, IN OUR

NEXT LOOK IN CHAPTER FOURTEEN WE’LL LOOK AT THE OTHER THREE: LIPIDS, PROTEINS, AND

NUCLEIC A CIDS.