1. Biochemistry Department
General Metabolism
By Dr. Wael Elayat

2. General Metabolism

3. Intended Learning Outcomes
By the end of this lecture , You will be able to:
Illustrate both arms of metabolism (Catabolic & anabolic pathways)& which of them are ATP producing OR consuming?
Give an example of the catabolic, anabolic & amphibolic pathways.
Illustrate the 3 stages of catabolic pathway
Enumerate the importance of metabolism
Define metabolic map and its significance.

4. Introduction:
1- In a cell, biochemical reactions are organized into multistep sequence called pathways.
2- In pathways, The product of one reaction act as the substrate of the subsequent reaction.
A B C D E

5. 3- Different metabolic pathways can intersect, forming integrated and purposeful network of chemical reactions 4- These collectively called metabolism, which is the sum of all chemical reactions occurring in a cell, in a tissue or the body.

6. is the set of CHEMICAL REACTIONS that occur in living organisms
Metabolism
is the set of CHEMICAL REACTIONS
that occur in living organisms
to maintain life.

7. Importance Of Metabolism
1-ATP production (Catabolic)
2- Allows molecules in diet ( or nutrient stored in cells) to be converted to building blocks for synthesis of complex molecules) (Catabolic)
3- Synthesis Of Complex Molecules (Anabolic)

8. Types of metabolic processes
Definition: break down of complex molecules into few simple molecules.
Importance:
1-ATP production
2- Conversion of molecules in diet ( or nutrient stored in cells) to be converted to building blocks for synthesis of complex molecules)
1- Catabolic

9. Nature of catabolic reactions: 1- Usually oxidative requiring hydrogen carriers e.g NAD 2- Convergent process: That is to say wide variety of molecules convert into few common end products

10. Stages of catabolic reactions
Catabolic reactions pass into 3 stages: 1- Stage 1: Hydrolysis of large complex molecules into their component building block. 2- Stage 2: Convergence of building blocks to simple intermediates (acetyl CoA and few other simple molecules). At this stage few amount of energy obtained in the form of ATP 3- Stage 3: Oxidation of acetyl CoA with production of large amount of ATP

11. Glyceraldehyde 3 phosphate
Proteins
Carbohydrate
lipids
Amino acids
Glucose
Glycerol + FA
1st Stage
Glyceraldehyde 3 phosphate
Pyruvate
2ed Stage
Acetyl CoA
Citric Acid
cycle
ETC
3d Stage
CO2
NH3

12. 2- Anabolic
Definition: Combination of small molecules (a.as) to form complex molecules (protein).
Importance: Synthesis Of Complex Molecules.
Nature:
1- Usually energy consuming (endergonic)
2- Mostly reductive (Utilize electron donor NADPH)
3- Divergent process: Few biosynthetic precursors form a wide variety of complex products.

13. 3- Amphibolic
They act as bot anabolic and catabolic (e.g. TCA)

14. Catabolic end Poroducts
Acetyl CoA
Final end products
ATP+ CO2, H2O+ N
Cat-3
Cat-2
Catabolism-1
Amphibolic
Macromolecules
Protein
Polysaccharides
Lipids
Nucleic acids
Catabolic end Poroducts
Amino acids
Simple Sugars FA
Nitrogenous bases
Anabolism

15. Corresponding Pathways Of Catabolism And Anabolism.
FA Oxidation & FA synthesis.
Glycogenolysis & Glycogenesis .
a.a Oxidation & Protein bisynthesis…etc

16. They are Not Simple Reverse Of each other
Corresponding Pathways Of Catabolism And Anabolism Are Different:
They are Not Simple Reverse Of each other

17. Instead, They follow different steps catalyzed by different enzymes
located in different locations
and each has its way of regulation.

18. Glycgenolysis X Glycogenesis FA Oxidation X FA synthesis
i.e. There are Specific enzymes present in Catabolic pathways
Which are NOT present in the Anabolic pathway
Catabolic
Anabolic

19. Metabolic map
What is metabolic map? A big picture containing the important central metabolic pathways of energy metabolism. Importance of metabolic map: 1- Trace connection between pathways 2- Visualize the purposeful movement of metabolic intermediate 3- Picturing the effect on the flow of intermediates if a pathway is blocked by drugs or disease

20. Metabolic map

21. Questions to assess the ILOs
Choose the best answer:
1- Metabolic reactions are:
a) Sum of all reactions occurring in a cell
b) Sequence of chemical reactions in which product of one reaction is a substrate for the other reaction
c) Mostly reductive reactions
d) Mostly oxidative reactions
e) Convergent reactions

22. 2- As regard anabolic reactions:
Combination of small molecules to form complex molecules
b) Mostly oxidative in nature
c) Require NAD as a hydrogen carrier
d) Convergent process
e) All of the above

23. Thank you
Dr. Wael Elayat