PROTEINPOLISAKARIDALIPIDBIOMOLEKUL ASAM AMINO GLUKOSA GLISEROL AS. LEMAK MOLEKUL PEMBANGUN PIRUVAT ASETIL-KoA Tahap II Tahap I Tahap III PRODUK PEMECAHAN UMUM PRODUK KATABOLISME SEDERHANA CO2H2OASETIL-KoA SIKLUS ASAM SITRAT PENTOSAHEKSOSA

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 heat heat (~ 70% of energy used in physical exercise)

Bioenergetics energyliving systems organismsThe study of energy in living systems (environments) and the organisms (plants and animals) that utilizing them.

Biochemical Pathways Copyright © McGraw-Hill Companies Permission required for reproduction or display

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 (CH 2 O)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)

Monosaccharide Structures Conformation of monosaccharide Conformation of 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

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 –NHCOCH 3 (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 Copyright © McGraw-Hill Companies Permission required for reproduction or display

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. Net reaction

Glucose priming

Cleavage and rearrangement PP

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 CO 2. –Four-carbon starting material is regenerated. Cycle is also known as –Tricarboxylic acid (TCA) cycle –Citric acid cycle citric acid

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 FADH 2 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 => CO 2 –Hydrogens transferred NAD+ => NADH FAD => FADH –Products of kreb cycle 3 NADHs 1 FADH 2 2 ATP

Electron Transport System

Energy CapacityperformCapacity to perform work. Two examples:Two examples: 1.Kinetic energy 2.Potential energy

Kinetic Energy Energyprocess of doing workEnergy in the process of doing work. Energy of motionEnergy of motion. Examples:Examples: 1.Heat 2.Light energy SUN

Potential Energy Energymatter occupies location, arrangement, or positionEnergy that matter occupies because of it’s location, arrangement, or position. Energy of positionEnergy of position. Examples:Examples: 1.Water behind a dam 2.Chemical energy (gas) GAS

Answer: adenosine triphosphate (ATP)adenosine triphosphate (ATP) Components:Components: 1.adenine:nitrogenous base 2.ribose:five carbon sugar 3.phosphate group: chain of three ribose adenine PPP phosphate group Question: ATP?What is ATP?

Answer: direct chemical transfer phosphate group.Works by the direct chemical transfer of a phosphate group. “phosphorylation”This is called “phosphorylation”. exergonic hydrolysis ATP endergonic processes transferring phosphate groupThe exergonic hydrolysis of ATP is coupled with the endergonic processes by transferring a phosphate group to another molecule.

Hydrolysis of ATP ATP + H 2 O  ADP + P (exergonic) Hydrolysis (add water) PPP Adenosine triphosphate (ATP) PP P + Adenosine diphosphate (ADP )

Dehydration of ATP ADP + P  ATP + H 2 O (endergonic) Dehydration synthesis (remove water ) (remove water ) PPP Adenosine triphosphate (ATP) PP P + Adenosine diphosphate (ADP )