Download MBBS Biochemistry PPT 65 Introduction To Metabolism Lecture Notes

Download MBBS (Bachelor of Medicine, Bachelor of Surgery) 1st year (First Year) Biochemistry ppt lectures Topic 65 Introduction To Metabolism Notes. - biochemistry notes pdf, biochemistry mbbs 1st year notes pdf, biochemistry mbbs notes pdf, biochemistry lecture notes, paramedical biochemistry notes, medical biochemistry pdf, biochemistry lecture notes 2022 ppt, biochemistry pdf.


Introduction

To

Metabolism

What is Metabolism?
? Metabolism is a network of metabolic /biochemical

reactions.

? Carried out in living cells.
? In a well organized, integrated and regulated manner.

? Related to various biomolecules viz

? Carbohydrates

? Lipids

? Proteins

? Nucleoproteins

?Metabolism involves

interconversions of chemical

compounds in the body.

? Metabolite precursors are

transformed to end products via

many specific intermediates.
?Metabolism is the sum of the

chemical changes that convert:

?Nutrients into energy.

?Chemical y complex substances of

cel s into simpler forms.

?Chemical y simple substances into

functional complex biomolecules.

The Sun is Energy for Life

Phototrophs (Plants) use light to

drive synthesis of organic

molecules.

Heterotrophs (Animals) use

these as building blocks.

CO2,O2 and H2O are recycled.


Importance Of Metabolism

?Normal Metabolism is vital for

health, growth, reproduction

and good survival of human

beings.
Role of Enzymes and Hormones

in Metabolism

?Enzymes along with Coenzymes

biocatalyze specific metabolic

reactions.

?Thus Enzymes are "Functional

units of Metabolism"
?Hormones are chemical

messengers of human body. They

are regulators of Enzyme activity.

(Hormones Stimulate/Inhibit

Enzyme activity)

?Enzyme reactions are

organized into discrete

pathways.
Metabolite

?Metabolite is a substrate or a

reactant undergoing a

biochemical/metabolic reaction.

Metabolic Reaction

? Metabolic reaction is a biochemical

reaction where a metabolite is specifically

reacted by an Enzyme and Coenzyme to

give a product.

A E-Co B
Types Of Metabolic Reactions

? Reversible Reactions ? Same Enzyme is required.
? Not regulatory steps.
E1

A E1 B




? Irreversible Reactions-

?Different set of Enzyme required.

?Non equilibrium Reactions.

?Regulatory steps.

E2

C

D

E3


Types Of

Biochemical Reactions

? Oxidation/Dehydrogenation/Hy

droxylation

? Reduction

? Hydrolytic

? Carboxylation

? Decarboxylation
? Phosphorylation

? Dephosphorylation

? Amination

? Deamination

? Isomerization

? Hydration

? Dehydration

Metabolic Pathway

?Metabolic pathway is a series of wel

defined and significant biochemical

reactions followed one after another

giving intermediate products and

finally end product of the pathway.
A Precursor of the pathway (A)

E1
B

E2

C Intermediates of the pathway (B,C,D)

E3
D

E4
E End Product of the pathway (E)

Organization of Pathways

? Pathways consist of sequential steps.

? The enzymes may be separate.

? May form a multienzyme complex.

? May be a membrane-bound system.

? New research indicates that multienzyme complexes

are more common than once thought.


Mutienzyme complex

Separate

enzymes

Membrane

Bound System

Organization of Pathways

Closed Loop

(intermediates recycled)

Linear

Spiral

(product of rxns are

(same set of

substrates for

enzymes used

subsequent rxns)

repeatedly)


Compartmentalization Of Metabolic

Pathways

?Compartmentalization of

pathways permits

integration and

regulation of metabolism.


Phosphoryl-group Transfer

Types Of Metabolic Pathway

?Catabolic/Degradative /Energy

Generating/ATP producing

Pathways/Exothermic.

?Anabolic/Synthetic/Energy Utilizing/

ATP Using Pathways/Endothermic.
?Catabolic pathways involve

oxidative reactions producing

reducing equivalents- NADH+H+

and FADH2.

?Catabolic pathways converge to

few end products.

?Anabolic pathways

diverge to synthesize

many biomolecules.

? .



?Some pathways serve both in

catabolism and anabolism ,those

are Amphibolic pathways.

?Amphibolic Pathways occur at the

crossroads of metabolism.

?Amphibolic pathways links between

Anabolic and Catabolic pathways.
Regulation of Metabolic

Pathways

?Regulation means stimulation and

inhibition of pathways as per cellular

need.

?Hormones regulate the metabolic

pathways.

?Metabolic pathways are regulated to

allow the organism to respond to

changing conditions.
?Every metabolic pathway has its

specific regulatory enzymes/key

enzymes.

?Hormones regulate by either

stimulating /inhibiting the

regulatory/key enzymes of the

pathway.

Modes Of Metabolic Regulation

? Al osteric regulation
? Covalent modification
? Control of enzyme levels
? Compartmentalization
? Metabolic specialization of organs


?Feedback inhibition ? product

of pathway down regulates

activity of early step in

pathway

?Feedforward activation ?

metabolite produced early in

pathway activates down stream

enzyme
Regulating Related Catabolic

? Anab a

oli n

c d

&

cA

atn

a a

bob

li o

c l

p iac

t

h Pa

waytsh

w

invoa

lvy

insg the

same compounds are not the same.

? Some steps may be common to both

? Others must be different - to ensure that each

pathway is spontaneous.

? This also al ows regulation mechanisms to turn

one pathway onn and the other off.

Modes Of Enzymes Regulation

?Alteration in membrane permeability.

?Conversion of Inactive to Active form.

?Stimulation of mRNA translation.

?Induction of new mRNA formation.

?Repression of mRNA formation.
?Knowledge of normal metabolism

is essential for :

?Understanding adaptations of

?Starvation

?Exercise

?Pregnancy and lactation.

?Understanding of metabolic

disorders.

Abnormal Metabolism Is Due To

vNutritional Deficiencies
vEnzyme Defects
vHormonal Defects
vDrug and Toxin Interactions
?Normal Enzyme and Hormonal

activities gives normal

metabolism and health to

human body.

?Defect in Enzymes and

Hormones derange the normal

metabolism.

Derangement in Metabolism

?Any defect or derangement in normal pattern of

metabolism leads to metabolic disorders.

?Mutation in Genes of Enzymes, forms defective

Enzymes.

?Congenital defect of Enzyme leads to Inborn

Error Of Metabolism.
Inborn Error Of Metabolism

?Congenital deficiency of any

single Enzyme of a metabolic

pathway leads to Inborn

Errors of Metabolism.

Enzyme Deficiency of a

Metabolic Pathway

? Blocks the metabolic reaction.

? Blocks the metabolic pathway.

? Accumulates and excrete intermediate

product of the pathway.

? No formation of end product of the

pathway.

? Affects other interrelated metabolic

pathways.
Methods Used to Study Metabolism

? Metabolic Reactions/Metabolic

Pathways were studied :

?Using whole organism/Cel ular

fractions

?Using Metabolic Probes.

?Using Radioisotopes.

This post was last modified on 05 April 2022