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Aulani "Biokimia" Presentation 3Aulani "Biokimia" Presentation 3
Carbohydrate MetabolismCarbohydrate Metabolism
Aulanni’amAulanni’amBiochemistry LaboratoryBiochemistry LaboratoryChemistry DepartementChemistry Departement
Brawijaya UniversityBrawijaya University
Aulani "Biokimia" Presentation 3Aulani "Biokimia" Presentation 3
CarbohydratesCarbohydrates
Carbohydrates are the most abundant organic Carbohydrates are the most abundant organic molecules in naturemolecules in nature Photosynthesis energy stored in carbohydrates;Photosynthesis energy stored in carbohydrates; Carbohydrates are the metabolic precursors of Carbohydrates are the metabolic precursors of
all other biomolecules;all other biomolecules; Important component of cell structures;Important component of cell structures; Important function in cell-cell recognition;Important function in cell-cell recognition; Carbohydrate chemistry:Carbohydrate chemistry:
Contains at least one asymmetric carbon Contains at least one asymmetric carbon center;center;
Favorable cyclic structures;Favorable cyclic structures; Able to form polymersAble to form polymers
Aulani "Biokimia" Presentation 3Aulani "Biokimia" Presentation 3
Carbohydrate Nomenclature
Carbohydrate Classes:Carbohydrate Classes: Monosaccharides (CHMonosaccharides (CH22O)nO)n
Simple sugars, can not be broken down Simple sugars, can not be broken down further;further;
OligosaccharidesOligosaccharides Few simple sugars (2-6). Few simple sugars (2-6).
PolysaccharidesPolysaccharides Polymers of monosaccharidesPolymers of monosaccharides
Aulani "Biokimia" Presentation 3Aulani "Biokimia" Presentation 3
Carbohydrate NomenclatureCarbohydrate Nomenclature
Monosaccharide (carbon numbers 3-7)Monosaccharide (carbon numbers 3-7) AldosesAldoses
Contain aldehydeContain aldehyde Name: aldo-#-oses (e.g., aldohexoses)Name: aldo-#-oses (e.g., aldohexoses)
Memorize all aldoses in Figure ?Memorize all aldoses in Figure ?
KetosesKetoses Contain ketonesContain ketones Name: keto-#-osesName: keto-#-oses ( (ketohexosesketohexoses))
CHO
OHH
OHH
OHH
OHH
CH2OH
1
2
3
4
56
CHO
OH
OHH
OHH
OHH
CH2OH
1
2
3
4
56
Aulani "Biokimia" Presentation 3Aulani "Biokimia" Presentation 3
Monosaccharide Structures
O
a
e
a
a
a
a
e
e
a
e
a
e
a
e
a
e
a
Oeee
Axis Axis
Chair Boat
O
OH
H
OH
H
OH
OH
CH2OH
H
HH
O
H
HO
H
H
H
H
HO2HC
OHHOOH
-D-glucopyranose
Conformation of monosaccharide
Conformation of glucose
Aulani "Biokimia" Presentation 3Aulani "Biokimia" Presentation 3
Disaccharides
Simplest oligosaccharides; Contain two monosaccharides linked by a
glycosidic bond; The free anomeric carbon is called reducing
end; The linkage carbon on the first sugar is
always C-1. So disaccharides can be named as sugar-(a,b)-1,#-sugar, where a or b depends on the anomeric structure of the first sugar. For example, Maltose is glucose-a-1,4-glucose. .
Aulani "Biokimia" Presentation 3Aulani "Biokimia" Presentation 3
Structures of Disaccharides
Note the linkage and reducing endsNote the linkage and reducing ends
HOH
O
CH2OH
OH
OH
21
3
6
4
5O
CH2OH
OH
OH
OH
23
6
4
5
1O
Lactose (galactose--1,4-glucose)
HOH
O
CH2OH
OH
OH
21
3
6
4
5O
CH2OH
OH
OH
OH 23
6
4
5
1
Maltose (glucose--1,4-glucose)
O2
O
CH2OH
OH
OH
OH 23
6
4
5
1O CH2OH
CH2OH
OH
OHO
1
3 64
5
Sucrose (glucose--1,2-froctose) no reducing end
HOH
O
CH2OH
OH
OH
21
3
6
4
5O
CH2OH
OH
OH
OH 23
6
4
5
1O
Cellobiose (glucose--1,4-glucose)
Aulani "Biokimia" Presentation 3Aulani "Biokimia" Presentation 3
PolysacchridesPolysacchrides Also called glycans;Also called glycans; Starch and glycogen are Starch and glycogen are storage storage molecules; molecules; Chitin and cellulose are Chitin and cellulose are structuralstructural molecules; molecules; Cell surface polysaccharides are Cell surface polysaccharides are recognitionrecognition molecules. molecules.
Glucose is the monosaccharides of the following polysacchrides with different linkages and banches
a(1,4), starch (more branch) a(1,4), glycogen (less branch) a(1,6), dextran (chromatography resins) b(1,4), cellulose (cell walls of all plants) b(1,4), Chitin similar to cellulose, but C2-OH is
replaced by –NHCOCH3 (found in exoskeletons of crustaceans, insects, spiders)
Aulani "Biokimia" Presentation 3Aulani "Biokimia" Presentation 3
Overview of Glucose Overview of Glucose CatabolismCatabolism
Cells catabolize organic molecules and make ATP two ways: Substrate-Level Phosphorylation
Glycolysis Krebs (TCA) Cycle
Oxidative Phosphorylation Electron Transport Chain
Aulani "Biokimia" Presentation 3Aulani "Biokimia" Presentation 3
Overview of Glucose CatabolismOverview of Glucose Catabolism
Aulani "Biokimia" Presentation 3Aulani "Biokimia" Presentation 3
Overview of Glucose CatabolismOverview of Glucose Catabolism
Glycolysis Biochemical pathway
that produces ATP by substrate-level phosphorylation.
Yields a net of two ATP molecules for each molecule of glucose catabolized.
Every living creature is capable of carrying out glycolysis.
Most present-day organisms can extract considerably more energy from glucose through aerobic respiration.
C H O P A D P N A D
C H O A T P N A D H H
6 1 2 6 i
3 4 3
2 2 2
2 2 2
•Net reaction
Aulani "Biokimia" Presentation 3Aulani "Biokimia" Presentation 3
Cleavage and Cleavage and rearrangementrearrangement
P P
Aulani "Biokimia" Presentation 3Aulani "Biokimia" Presentation 3
Krebs Cycle
After pyruvate has been oxidized, acetyl- CoA feeds into the Krebs cycle.
Krebs cycle is the next step of oxidative respiration and takes place in mitochondria. Occurs in three stages:
Acetyl-CoA binds a four-carbon molecule and produces a six-carbon molecule.
Two carbons are removed as CO2.
Four-carbon starting material is regenerated.
Cycle is also known as Tricarboxylic acid
(TCA) cycle Citric acid cycle
CH2
COOH
C
CH2
COOH
OH COOH
citric acid
Aulani "Biokimia" Presentation 3Aulani "Biokimia" Presentation 3
Aerobic RespirationAerobic Respiration The pyruvic acid formed by glycolysis enters interior of The pyruvic acid formed by glycolysis enters interior of
mitochondria.mitochondria. Converted by coenzyme A to 2 molecules of acetyl CoA and 2 C0Converted by coenzyme A to 2 molecules of acetyl CoA and 2 C022.. Acetyl CoA serves as substrate for mitochondrial enzymes in the Acetyl CoA serves as substrate for mitochondrial enzymes in the
aerobic pathway.aerobic pathway.
Aulani "Biokimia" Presentation 3Aulani "Biokimia" Presentation 3
CO2
CO2
CO2
NADHNADH
FADH
GTP
oxaloacetate (4C)
citrate (6C)
-ketoglutarate (5C)succinate (4C)
acetyl coenzyme A (2C)
pyruvate (3C)
NADH
Aulani "Biokimia" Presentation 3Aulani "Biokimia" Presentation 3
Krebs CycleKrebs Cycle
Generates two ATP molecules per molecule of glucose.
Generates many energized electrons which can be directed to the electron transport chain to drive synthesis of more ATP: 6 NADH per molecule of glucose 2 FADH2 per molecule of glucose
Aulani "Biokimia" Presentation 3Aulani "Biokimia" Presentation 3
KREBS CYCLEKREBS CYCLE Takes place in Mitochondrion when oxygen is present Pyruvic acid from glycolysis is trimmed to a 2 carbon
compound Remaining carbon from glucose => CO2
Hydrogens transferred NAD+ => NADH FAD => FADH
Products of kreb cycle 3 NADHs 1 FADH2
2 ATP
Aulani "Biokimia" Presentation 3Aulani "Biokimia" Presentation 3
The Cori Cycle
The reconversion of lactic acid to pyruvate sees the removal of fatiguing lactate from the site of production.
This forms the theoretical basis for the cool-down.
As the glycolysis pathway is reversible lactic acid can eventually be anabolised into glucose and stored in the liver, muscles or blood.
Aulani "Biokimia" Presentation 3Aulani "Biokimia" Presentation 3
Electron Transport SystemElectron Transport System
Aulani "Biokimia" Presentation 3Aulani "Biokimia" Presentation 3
Electron Transport SystemElectron Transport System
Aulani "Biokimia" Presentation 3Aulani "Biokimia" Presentation 3
EnergyEnergy CapacityCapacity to to performperform workwork..
Two examples:Two examples:
1.1. Kinetic energyKinetic energy
2.2. Potential energyPotential energy
Aulani "Biokimia" Presentation 3Aulani "Biokimia" Presentation 3
Kinetic EnergyKinetic Energy EnergyEnergy in the process of doing work. in the process of doing work.
EnergyEnergy of of motionmotion..
Examples:Examples:
1.1. HeatHeat
2.2. Light energyLight energy
SUN
Aulani "Biokimia" Presentation 3Aulani "Biokimia" Presentation 3
Potential Energy Energy that matter occupies because of it’s
location, arrangement, or position.
Energy of position.
Examples:1. Water behind a dam2. Chemical energy (gas)
GAS
Aulani "Biokimia" Presentation 3Aulani "Biokimia" Presentation 3
Answer:Answer: adenosine triphosphate (ATP)adenosine triphosphate (ATP) Components:Components:
1.1. adenine:adenine: nitrogenous basenitrogenous base
2.2. ribose:ribose: five carbon sugarfive carbon sugar
3.3. phosphate group: chain of threephosphate group: chain of three
riboseribose
adenineadenine
P P P
phosphate groupphosphate group
Question:Question: What isWhat is ATP?ATP?
Aulani "Biokimia" Presentation 3Aulani "Biokimia" Presentation 3
Answer:Answer: Works by the Works by the direct chemical transferdirect chemical transfer of a of a
phosphate groupphosphate group..
This is called This is called “phosphorylation”“phosphorylation”..
The The exergonic hydrolysisexergonic hydrolysis of of ATPATP is coupled with is coupled with the the endergonic processesendergonic processes by by transferringtransferring a a phosphate groupphosphate group to another molecule. to another molecule.
Aulani "Biokimia" Presentation 3Aulani "Biokimia" Presentation 3
Hydrolysis of ATPHydrolysis of ATP
ATP + HATP + H22O O ADP + P (exergonic) ADP + P (exergonic)
HydrolysisHydrolysis(add water)(add water)
P P P
Adenosine triphosphate (ATPAdenosine triphosphate (ATP))
P P P++
Adenosine diphosphate (ADPAdenosine diphosphate (ADP))
Aulani "Biokimia" Presentation 3Aulani "Biokimia" Presentation 3
Dehydration of ATPDehydration of ATP
ADP + P ADP + P ATP + H ATP + H22O (endergonic)O (endergonic)
Dehydration synthesisDehydration synthesis
(remove water(remove water))
P P P
Adenosine triphosphate (ATP)Adenosine triphosphate (ATP)
P P P++Adenosine diphosphate Adenosine diphosphate
(ADP(ADP))