- WELCOME TO METABOLISM AND BIOENERGETICS PART ONE.
THIS TUTORIAL WILL GIVE AN OVERVIEW
AND THEN FOCUS ON ACETYL COA.
WE'VE BEEN HEARING A LOT ABOUT IT, RIGHT?
ACETYL COA PRODUCTION IS CONSIDERED LIKE THE SECOND STAGE
OF CATABOLISM.
SO LET'S LOOK A LITTLE MORE CLOSELY
AT THIS IMPORTANT MOLECULE.
LET'S GET STARTED.
ALL RIGHT. SO LET'S REMEMBER--
RIGHT. SO METABOLISM IS ALL OF THE BIOCHEMICAL REACTIONS
THAT ABOUT TO USE PRODUCTION AND STORAGE OF ENERGY.
AND SO WE'VE LEARNED ANABOLISM, RIGHT.
THAT'S THE SYNTHETIC OR REDUCTIVE,
REQUIRES ENERGY, RIGHT?
SO ENDOTHERMIC, WE WILL LEARN A NEW WORD IN THIS CHAPTER
AND THEN CATABOLISM THAT'S DEGRADATIVE AND--
OR DEGRATION AND IT'S OXIDATIVE AND THOSE PRODUCE ENERGY,
SO WE CAN THINK EXO.
ALL RIGHTY.
SO WE'VE GONE THROUGH THE FIRST STAGE VERY THOROUGHLY.
SO YOU GUYS ARE ALL EXPERTS NOW AT HYDROLYSIS WHICH IS GREAT.
SO THE LARGE COMPLEX FOOD MOLECULES GET
BROKEN DOWN INTO THEIR MONOMERS OR SIMPLE--
SIMPLER MOLECULES.
AND NOW IN THIS CHAPTER
WHERE WE'RE REALLY GOING TO FOCUS-- OH,
AND WE'VE ALREADY TALKED ABOUT THE ACETYL COA PRODUCTION
FOR THE MOST PART TOO.
ACETYL COA PRODUCTION BUT WE REALLY HAVEN'T LOOKED CLOSELY
AT THIS MOLECULE, RIGHT?
SO BASICALLY ALL ROADS LEAD TO ACETYL COA.
ALL ROADS, ALL PATHS LEAD TO ACETYL COA, RIGHT?
REGARDLESS OF WHETHER WE STARTED WITH A PROTEIN, A CARBOHYDRATE,
OR A FAT, OUR BODY HAS A WAY TO GET THOSE INTO ACETYL COA
AND WHY IS THAT?
BECAUSE--
THIS WILL BE AN EMPHASIS IN THIS CHAPTER, RIGHT,
THE ENERGY PRODUCTION. OKAY.
SO AFTER WE LOOK AT ACETYL COA A LITTLE MORE CLOSELY,
WE'LL FINALLY STUDY THE CITRIC ACID CYCLE
AND THE ELECTRON TRANSPORT CHAIN, RIGHT?
BECAUSE THE BIG DEAL IS WE WANT TO GET ATP OR ENERGY CURRENCY.
AND WE DON'T GET TO TALK A LOT ABOUT UREA BUT--
SO I WANTED TO JUST BRIEFLY TALK ABOUT AMINO ACIDS, RIGHT.
AMINO ACIDS CONTAIN NITROGEN AND IT'S VERY INTERESTING.
OUR BODY CAN STORE CARBON, OXYGEN,
AND HYDROGEN BUT OUR BODY CANNOT STORE NITROGEN.
SO ANY EXCESS NITROGEN ATOMS FROM THE AMINO ACID
THAT WE CAN'T HOLD IN THE AMINO ACID POOL CREATE AMMONIA
OR AMMONIUM IONS AND THESE ARE TOXIC.
AND SO THERE IS A METABOLIC PATHWAY
THEN CALLED THE UREA CYCLE
WHICH CONVERTS THE AMMONIUM IONS INTO UREA
WHICH CAN THEN BE EXCRETED FROM OUR KIDNEYS.
OOPS, LET ME SLIDE THAT UP, TO--
RIGHT, THROUGH OUR URINE.
ALL RIGHT. SO WE DON'T--
THIS IS ABOUT THE ONLY PLACE
I CAN THINK TO ADD THAT INFORMATION AND I THINK
IT'S IMPORTANT TO OUR OVERALL UNDERSTANDING OF METABOLISM.
SO NOW WE'LL GO AHEAD AND MOVE ON TO THE NEXT PAGE
AND LOOK AT WHAT HAPPENS RIGHT
BEFORE THE CITRIC ACID CYCLE, RIGHT?
SO RIGHT BEFORE THE CITRIC ACID CYCLE WE NEED TO LOOK AT--
WE'VE SEEN HOW FATS--
FATTY ACIDS CAN PRODUCE ACETYL COA.
LET'S LOOK A LITTLE MORE CLOSELY AT WHAT HAPPENS WITH PYRUVATE
AND ACETYL COA. OKAY.
SO LET'S GET OUR NEXT PAGE CENTERED.
THERE WE GO. ALL RIGHTY.
SO HERE'S PYRUVATE.
SO BY NOW YOU PROBABLY HAVE THE STRUCTURE
IN YOUR MIND AND IF NOT,
IT'S A GOOD TIME TO GET IT THERE, RIGHT.
SO THIS IS OUR-- GOING TO BE ANOTHER EXAMPLE
OF THE THIOESTER FORMATION, RIGHT.
SO HERE IS OUR CARBONYL CARBON
AND THE CARBOXYLIC ACID AND THESE WILL COME TOGETHER,
RIGHT, TO GET THE WATER THAT'S TYPICALLY NOT SHOWN
IN THE PATHWAYS.
AND WE GET OUR THIOESTER.
NOTICE IN THE PROCESS, WE DO PRODUCE A REDUCED COENZYME
AND THIS SUBSTANCE HERE IS COENZYME A, RIGHT.
AND SO WE'VE ALREADY TALKED ABOUT THIS BUT--
OH, AND THIS WILL FILL IN THE BLANKS
FOR THE LIPIDS, RIGHT.
SO PYRUVATE, RIGHT, IT COMES-- RIGHT.
SO FROM GLUCOSE-- RIGHT.
SO FROM GLUCOSE GLYCOLYSIS,
RIGHT, WE PRODUCE PYRUVATE
AND WE CAN ALSO PRODUCE IT FROM THE GLYCERIN FROM FATS. OKAY.
AND SO HERE WE HAVE IT BUT NOTICE
THAT WE ALWAYS JUST TEND TO SAY COA. ALL RIGHT.
SO THIS IS THE PAGE WHERE WE LOOK MORE CLOSELY AT EXACTLY
WHAT THE STRUCTURE IS OF COA,
COENZYME A. SO--
AND THEN ONCE YOU SEE THIS YOU'LL KNOW
WHY WE ABBREVIATE IT, RIGHT?
IT'S A HUGE MOLECULE. ALL RIGHT.
SO THIS IS THE ENTIRE STRUCTURE FOR ACETYL COA.
ALL RIGHT.
SO THERE ARE THREE PRIMARY PIECES--
WELL, THERE'S FOUR PRIMARY PIECES.
HERE WE HAVE THE ADENOSINE, RIGHT.
SO THERE IS THE ADENINE,
THERE'S OUR NITROGENOUS BASE AND OUR SUGAR AND OUR PHOSPHATES.
AND THEN WE HAVE THE PANTOTHENIC ACID, THE THYLAMINE
AND THE ACETIC ACID. ALL RIGHT.
SO THESE FOUR COMPOUNDS COME TOGETHER
TO CREATE ACETYL COA, RIGHT?
SO WHEN YOU SEE COENZYME A, IT'S THESE THREE MOLECULES.
AND THEN WHEN WE ADD THE ACETYL GROUP.
ALL RIGHTY.
SO LETS PRACTICE CLASSIFYING THOSE BONDS.
SO TAKE A MOMENT TO DO THAT. OKAY.
AND SO WHEN WE LOOK AT THIS BOND RIGHT HERE,
RIGHT, WE RECOGNIZE THAT AS A THIOESTER.
SO THAT'S THE BOND
THAT WE SHOWED THAT WAS FORMED IN THE REACTION ABOVE, RIGHT.
SO SEE REACTION ABOVE.
AND NOW, IF WE LOOK CLOSELY, THE THYLAMINE,
HOW DOES IT CONNECT TO THE PANTOTHENIC ACID?
WHAT TYPE OF BOND IS THAT?
ALL RIGHT. SO WE--
THAT IS AN AMIDE BOND, RIGHT.
SINCE THESE AREN'T PROTEINS AND AMINO ACIDS,
WE DON'T CALL IT A PEPTIDE BOND.
WE WOULD CALL IT AN AMIDE BOND.
AND THEN THE LAST LINKAGE IS RIGHT HERE, RIGHT.
AND WE CAN LOOK AT THE PANTOTHENIC ACID
AND WE NOTICE IT WAS AN ALCOHOL,
AN ALCOHOL LINKING TO A PHOSPHORIC ACID, RIGHT.
SO THAT'S A PHOSPHATE ESTER BOND.
OKAY. SO THERE ARE THE THREE--
THE THREE BONDS THAT LINK TOGETHER,
THE FOUR COMPOUNDS TO CREATE ACETYL COA, RIGHT?
SO ACETYL COA.
ALL RIGHTY.
SO THAT WRAPS UP OUR INTRODUCTION
TO METABOLISM AND BIOENERGETICS.
AND NOW IN THE FUTURE TUTORIALS,
WE'LL DIG IN DEEPER AND LOOK AT THE CITRIC ACID CYCLE
AND THE ELECTRON TRANSPORT CHAIN.
SO STAY TUNED FOR MORE INFORMATION.