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53 Cards in this Set
- Front
- Back
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Metabolism
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-The sum total of all the chemical reactions that go in living cells.
*This includes all the reactions by which the body obtains and spends the energy from food. -Involves the breakdown of: -carbohydrates --> glucose -fats --> glycerol + FA -proteins --> amino acids -Also involves the reverse of each reaction -Building of CHO, fats, proteins |
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Catabolism
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-Reactions in which larger molecules are broken down to smaller ones
-Ex. of a catabolic reaction: Hydrolysis of sucrose to glucose + fructose |
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Anabolism
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-Reactions in which small molecules are put together to build larger ones.
-These reactions require energy. -Ex. of an anabolic reaction: Production of proteins from individual AA |
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Anabolic Vs. Catabolic
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Anabolic Reactions:
-Glycogen, triglycerides, protein uses energy Catabolic Reactions: -yields energy |
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Energy is the capacity to do work
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-Down hill reactions vs. up hill reactions
-Dictated by the release or absorption of energy. -Down hill reactions are spontaneous and exergonic -Up hill reactions are non-spontaneous and endergonic |
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ATP
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-Adenosine tri-phosphate (ATP)
-The most basic unit of chemical energy in living organisms -Is a high energy molecule that can be broken down and reformed through various coupled reactions -Ability to create energy is due to its high energy bonds -Is the end product of all major catabolic reactions in living cells -Hydrolysis of CHO, fats, and amino acids |
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End product of complete hydrolysis
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1. Water
2. Carbon dioxide 3. ATP |
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Phosphate high energy bonds of ATP
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-Breaking of high energy bond gives off energy
- ~ <--represents high energy bond -Ex. P~P~P Tri-phosphate P~P x PI Di-phosphate + free phosphate |
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Formation and use of ATP
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-ADP+P: energy from food is used to attach a phosphate group to adenosine diphosphate(ADP), making ATP
-ATP: captures and stores this energy -ADP+P: energy from ATP is released when a phosphate bond is broken. This energy fuels the body's work. |
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Coupled Reactions
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-The pairing of an exergonic rxn with an endergonic rxn
-energy released from one reaction is used to drive the other -Hydrolysis of ATP is the major exergonic reaction used *Rube Goldberg device |
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Energy systems of the body
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-Designed to produce ATP in order for the body to do work
-catabolize food--> to build ATP -catabolize ATP--> to build body structures |
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ATP is formed by four major pathways
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1. Phosphorylation of ADP by creatine phosphate
2. Via glycolysis 3. Via the TCA cycle 4. Electron transport chain(ETC) *3 and 4 work together |
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ATP/SP System
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-Fast energy
-CP donates Pi to ADP to form ATP -CP+ADP--->ATP+creatine |
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Glycolysis
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-Anaerobic or fast oxidative
-Break down of glucose -Pyruvate is end product -Lactate (anaerobic) |
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TCA Cycle
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-Also called Kreb cycle
-Aerobic -Breakdown of: 1. CHO 2. Fat 3. AA |
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Electron Transport Chain
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-Most abundant producer of ATP
-Aerobic -Passing of hydrogen across membrane |
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Oxidation and Reduction Reactions
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-Responsible for production of ATP
-Oxidation- removal of hydrogen -Reduction- addition of hydrogen AH+B--->A+BH (Redox rxn) |
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Site of Metabolic Activity
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-Cell is the site of metabolic activity
-Cytosol and mitochondria -Types of metabolism depends on: -Type of cell -Location of cell |
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Enzymes catalyze reactions
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-Usually responsible for the start-up energy
-Ex. Pushing the boulder at the top of the hill -Coenzymes or cofactors aid enzymes -Vitamins and minerals -Not proteins but associate with proteins -Ex. of coenzyme: CoA is the B vitamin pantothenic acid |
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Where metabolism takes place
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-Takes place in all tissues of the body
-Main site is the liver -Carbohydrate metabolism -Fat metabolism -Protein metabolism -Detoxifies body -Dismantles old blood cells |
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Metabolism: Carbohydrates
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-Glucose is the main monosaccharide
-Four pathways associated with CHO 1. Glycolysis 2. Gluconeogenesis 3. Glycogenesis 4. Glycogenolysis |
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Metabolism: Carbohydrates
Glycolysis |
-Convert glucose (6 carbon) into pyruvate (3 carbon)
-Can be aerobic or anaerobic -When anaerobic, pathway produces Lactate |
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Glycolysis and Energy
Direct Formation |
-2 ATP are used to split glucose into two 3 C molecules
-A total of 4 ATP are created when converting glyceraldehyde-3-PO to pyruvate -Net ATP from one glucose is 2 |
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Lactate Production
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-NADH+H+ reduces pyruvate to lactate so that it returns to glycolysis to collect more H+
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Metabolism: Carbohydrates
When Conditions are Anaerobic |
-Little energy yield (rapid fatigue)
-Build up of Lactate (burn sensation) --Lactate can be shipped to liver and be converted back to glucose -Cori cycle -Glucose then can be reused |
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Metabolism: Carbohydrates
When Conditions are Aerobic |
-NADH+H+ are shipped to ETC for ATP production
-Each NADH+H+ yields 3 ATP -One glucose yields 3 ATP -One glucose yields 2 NADH+H+ -Fate of pyruvate is conversion to acetyl-CoA |
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Aerobic Vs. Anaerobic
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-Anaerobic glycolysis produces 2 ATP per one glucose
-Aerobic glycolysis produces 8 ATP per one glucose --Aerobic glycolysis also allows pyruvate to be converted to acetyl-CoA which can enter the TCA cycle |
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Metabolism: Carbohydrates
Gluconeogenesis |
-Reproduction of glucose in body
-Reverse of glycolysis -In live and in special cases in kidney -Can be made from: Pyruvate, some AA, Glycerol -Cannot be formed from acetyl-CoA -Liver creates glucose to regulate blood sugar levels -Kidney creates glucose during periods of starvation |
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Metabolism: Carbohydrates
Glycogenesis |
-The production of glycogen in the liver and muscle
-Liver again uses glycogen for blood sugar regulation -Muscle creates for its own use |
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Glycolysis and Energy
Indirect Formation |
-NADH+H+ produced (niacin)
-NAD is reduced by two hydrogen removed during glycolysis -In aerobic conditions NADH+H+ can be used to create 3 ATP (ETC) -In anaerobic conditions NADH+H+ must be oxidized for reuse |
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Metabolism: Carbohydrates
Glycogenolysis |
-The break down of glycogen to glucose
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TCA Cycle
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-Tricarboxylic Acid Cycle
-Or Kreb cycle -Or Citrate cycle -Repeating cycle -starts with acetyl-CoA binding with OAA to form citrate -works in conjunction with ETC to form ATP |
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Pyruvate converted to acetyl-CoA
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-Rxn produces NADH+H+
-when converted to acetyl-CoA it cannot be changed back to pyruvate -Acetyl-CoA can now enter the TCA cycle -Aerobic energy -Acetyl-CoA combined with OAA to form citrate -this sets the wheel into motion -series of rxn which produce NADH+H+ and FADH -the end product of pathway is OAA -OAA can then bind with another acetyl-CoA |
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ETC
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-System by which we can create ATP from NADH+H+ and FADH
-Series of hydrogen pumps which are powered by the passing of electrons -Production of ATP powered by a concentration gradient -Water is a bi-product |
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By passing electrons across the inner membrane of the mitochondria:
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-Energy is produced
-The energy powers H+ pumps -H+ pumped from low [] to high [] --H+ are then naturally pulled by [] gradient back through protein channel -ATP synthase -[] gradients powers production of ATP |
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Energy (CHO)
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-One glucose yields aerobically
-8 ATP via glycolysis -3 ATP for each conversion of pyruvate to acetyl-CoA (6 ATP) -12 ATP per acetyl-CoA via TCA cycle and ETC (24 ATP) ---Total of 38 ATP per one glucose |
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Metabolism: Fats
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-The goal of fat metabolism is to break triglycerides down to acetyl-CoA
-Lypolysis -Break down of triglycerides -B-Oxidation -Break down of FA into acetyl-CoA |
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Breakdown of Triglycerides
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-Lipolysis catalyzed by hormone sensitive lipase (HSL)
-Via diet -(chylomicrons) -Via adipose tissue |
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B-Oxidation or fatty acid oxidation
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-FFA can be shipped to cell for B-Oxidation
-Takes place in the mitochondria -Needs carnitine to get FA mitochondria -Involves two oxidation rxn per turn -End result is acetyl-CoA -Produces 1 NADH+H+ and 1 FADH --Repeating cycle; Yields a lot of energy -For each cleavage: 1. NADH+H+ 2. FADH 3. Acetyl-CoA |
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Glycerol can be converted into:
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-Glucose via gluconeogenesis
-Pyruvate via glycolysis *FFA cannot be changed into glucose |
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Metabolism: Fat
Lipogenesis |
-Formation of new FA
-Takes place in the liver -Use of acetyl-CoA --Fat can be made from: -CHO, AA |
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Metabolism: Fat
Ketone Production |
-Starvation
-Low CHO -Diabetes --Produced by binding of two acetyl-CoA -act as a CHO substitute -Used in: Brain and Muscle |
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Metabolism: Amino Acids
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-Not preferred fuel source for body
-Can be used as energy in various ways -Must be deaminated before used for energy -2 categories -Glucogenic(sugar making) -Ketogenic (fat making) |
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Metabolism: Amino Acids
First step of conversion to energy |
-To deaminate an AA
-Two ways: -Transamination -Oxidative deamination (only glutamate) |
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Transamination
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-The amine group from one AA is transferred to another AA analogue (keto acid)
-Common means by which body makes non-essential AA -Often involves glutamate --Keto acid can then enter metabolic pathways in various points |
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Oxidative Deamination
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-Produces NADH+H+
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Glutamate
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-Often paired in transamination rxn
-Significant way to remove NH from body -Nitrogen removal: -As Urea -As Ammonium (NH) |
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Ammonium Production
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-Acts as acid buffer
-Produced in liver --Other alternative uses of ammonia: -reductive reamination -production of amides (glutamine and asparagine) |
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AA converted into:
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-Pyruvate
-Acetyl-CoA -Other intermediates --3 Common conversions -Alanine--->pyruvate -Glutamate--->alpha keto glutarate -Aspartate--->OAA |
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Metabolism Overview:
Glucose |
-Begins with glycolysis
-Formation of pyruvate -Anaerobic and aerobic -Enters TCA cycle -38 ATP produced |
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Metabolism: Overview
Fats |
-Begins with lypolysis
-Formation of acetyl-CoA -Only aerobic -B-Oxidation -Cannot be converted into glucose |
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Metabolism: Overview
Amino Acids |
-Not preferred fuel
-Deamination -Nitrogen removal -Enters in various ways -Can make either fats or CHO |
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Metabolism: Overview
Hormonal balance between storage and mobilization |
-Insulin (storage)
1. Glycolysis 2. Glycogenesis 3. Lipogenesis -Glucogon, epinephrine, (mobilization) 1. Gluconeogenesis 2. Glycogenolysis 3. Lipolysis |
