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))