Post on 18-Dec-2015
PROTEIN POLISAKARIDA LIPID BIOMOLEKUL
ASAM
AMINO GLUKOSAGLISEROL
AS. LEMAK
MOLEKUL
PEMBANGUN
PIRUVAT
ASETIL-KoA
Tahap II
Tahap I
Tahap III
PRODUK
PEMECAHAN
UMUM
PRODUK
KATABOLISME
SEDERHANACO2H2OASETIL-KoA
SIKLUS ASAM
SITRAT
PENTOSA HEKSOSA
Metabolism
• Definition ?
• Metabolic pathways = network of linked reactions
• Basic feature: coupling of exergonic rxs with endergonic rxs. (direct vs. indirect coupling)
• Metabolism– Catabolism (ATP production)– Anabolism (Synthetic pathways
Potential Energy
Kinetic Energy
WORK
heatheat (~ 70% of energyused in physical exercise)
BioenergeticsBioenergetics
• The study of energyenergy in living systemsliving systems (environments) and the organismsorganisms (plants and animals) that utilizing them.
Biochemical Pathways
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How Cells Use Energy
• Adenosine Triphosphate (ATP) is the molecule in cells that supplies energy. – Five-carbon sugar (ribose)– Adenine (nucleotide base)– Chain of three phosphate groups
• Most energy exchanges in cells involve cleavage of the outermost phosphate bond, converting ATP into ADP and inorganic phosphate.
ATP-ADP Cycle
Carbohydrates
• Carbohydrates are the most abundant organic molecules in nature– Photosynthesis energy stored in carbohydrates;– Carbohydrates are the metabolic precursors of all other
biomolecules;– Important component of cell structures;– Important function in cell-cell recognition;– Carbohydrate chemistry:
• Contains at least one asymmetric carbon center;• Favorable cyclic structures;• Able to form polymers
9
Carbohydrate Nomenclature (I)
• Carbohydrate Classes:– Monosaccharides (CH2O)n
• Simple sugars, can not be broken down further;
– Oligosaccharides• Few simple sugars (2-6).
– Polysaccharides• Polymers of monosaccharides
Carbohydrate Nomenclature (II)
• Monosaccharide (carbon numbers 3-7)– Aldoses
• Contain aldrhyde• Name: aldo-#-oses (e.g., aldohexoses)
Memorize all aldoses in Figure ?
– Ketoses• Contain ketones• Name: keto-#-oses (ketohexoses)
CHO
OHH
OHH
OHH
OHH
CH2OH
1
2
3
4
56
CHO
OH
OHH
OHH
OHH
CH2OH
1
2
3
4
56
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
Conformationof monosaccharide
Conformationof glucose
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-(,)-1,#-sugar, where or depends on the anomeric structure of the first sugar. For example, Maltose is glucose--1,4-glucose.
Strutures of Disaccharides
Note 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)
Polysacchrides
• Also called glycans;• Starch and glycogen are storage molecules; • Chitin and cellulose are structural molecules;• Cell surface polysaccharides are recognition 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)
Overview of Glucose Catabolism
• Cells catabolize organic molecules and make ATP two ways:– Substrate-Level Phosphorylation
• Glycolysis• Krebs (TCA) Cycle
– Oxidative Phosphorylation• Electron Transport Chain
Overview of Glucose Catabolism
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Overview 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
Glucose priming
Cleavage and rearrangement
P P
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
CO2
CO2
CO2
NADHNADH
FADH
GTP
oxaloacetate (4C)
citrate (6C)
-ketoglutarate (5C)succinate (4C)
acetyl coenzyme A (2C)
pyruvate (3C)
NADH
Krebs Cycle
Krebs 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
Glycolysis
Bioenergetics
• KREBS 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
Electron Transport System
Electron Transport System
EnergyEnergy
• CapacityCapacity to performperform work.
• Two examples:Two examples:
1.1. Kinetic energyKinetic energy
2.2. Potential energyPotential energy
Kinetic EnergyKinetic Energy
• EnergyEnergy in the process of doing workprocess of doing work.
• EnergyEnergy of of motionmotion.
• Examples:Examples:
1.1. HeatHeat
2.2. Light energyLight energy SUN
Potential EnergyPotential Energy
• EnergyEnergy that matter occupies matter occupies because of it’s location, arrangement, or positionlocation, arrangement, or position.
• EnergyEnergy of position of position.
• Examples:Examples:
1.1. Water behind a damWater behind a dam
2.2. Chemical energy (gas)Chemical energy (gas)GAS
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 is ATP?ATP?
Answer:Answer:• Works by the direct chemical transferdirect chemical transfer of a
phosphate groupphosphate group..
• This is called “phosphorylation”“phosphorylation”.
• The exergonic hydrolysisexergonic hydrolysis of ATPATP is coupled with the endergonic processesendergonic processes by transferringtransferring a phosphate groupphosphate group to another molecule.
Hydrolysis of ATPHydrolysis of ATP
• ATP + H2O ADP + P (exergonic)
HydrolysisHydrolysis(add water)(add water)
P P P
Adenosine triphosphate (ATP)Adenosine triphosphate (ATP)
P P P++
Adenosine diphosphate (ADPAdenosine diphosphate (ADP))
Dehydration of ATPDehydration of ATP
ADP + P ATP + H2O (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))