Enzymes 2 nd Year Nutrition By Eman Mokbel Alissa, Ph.D

Enzymes 2nd Year Nutrition

By

Eman Mokbel Alissa, Ph.D.Eman Mokbel Alissa, Ph.D.

Lecture (1): Lecture Content

• Enzyme definition

• Nomenclature

• Classification

• Coenzymes

• Properties

• 2 hypothesis of enzyme specificity

Lecture (2): Lecture Content

• Mechanism of enzyme action

• Mechanism of enzyme catalysis

• The Enzyme Substrate Complex

• Factors Affecting Reaction Velocity

• Enzymes Kinetics

• Michaelis-Menten equation

• Linweaver-plot

Lecture (3): Lecture Content

• Enzymes Inhibitors:

–Reversible and irreversible

–Competitive and noncompetitive

• Medical relevance of enzyme Inhibitors

• Antibiotics

• Enzymes Clinical Application

Lecture (4): Lecture Content

• Allosteric enzymes• Allosterism vs. Cooperativity• Allosteric Enzymes Kinetics• Feed back inhibition• Homotropic and Heterotropic effectors• Enzyme Activity Regulation• Enzyme measurements• Plasma Enzymes• Serum enzymes in Diagnosis• Isozymes

Amino Acids Amino Acids MetabolismMetabolism

2nd Year Nutrition

By

Eman Mokbel Alissa, Ph.D.Eman Mokbel Alissa, Ph.D.

Lecture (1) content

• amino acids in anabolic pathways• amino acids degradation• Carbon skeleton of amino acids• amino acids Pool • Inter-tissue Relationships in amino acids

Metabolism• Protein Turnover• Nitrogen balance• Digestion, Absorption and Transport

Lecture (2) content• Relationship to central metabolism• Nitrogen disposal

1. amino acids oxidases2. Transamination (aminotransferases/ transaminases)3. Glutamate dehydrogenase (amino acids oxidative

deamination)• Ammonia transport to liver

1. Glutamine cycle2. Glucose- Alanine cycle

• Urea Cycle– Regulation of urea cycle– Link between urea cycle and TCA cycle

Lecture (3) content

• Sources and Fates of Ammonia

• Hyperammonemia

• Essential and nonessential amino acids

• Glucogenic and ketogenic amino acids

• Synthesis and degradation in fasting and fed states

• Nonessential amino acids synthesis

Lecture (4) content

• Catabolism of carbon skeleton of amino acids

• Tetrahydrobiopterin (BH4)

• Role of folic acid in a a metabolism

• S-adenosyl methionine (SAM)

• Metabolism of branched chain amino acids

• Clinical relevance

Lecture (5) content

• Metabolic defects in a a metabolism

1. Phenylketonuria 2. Maple syrup

urine disease 3. Albinism 4. Homocystinuria 5. Alkaptonuria

• A A conversion to specialized products

1. Porphyrins

2. Catecholamines

3. γ-aminobutyrate

4. Glutathione

5. Creatine

6. Histamine

7. Serotonin

8. Melanin

Hormonal ControlHormonal Control 2nd Year Nutrition

By

Eman Mokbel Alissa, Ph.D.Eman Mokbel Alissa, Ph.D.

Lecture (1) content• Endocrine system• Cell to cell signaling • Feedback loops• Endocrine axis• Factors controlling hormone secretion• Assessment of endocrine control• Hormones Structure • Chemical nature• Signal transduction

– Hydrophobic hormones– Hydrophilic hormones

Lecture (2) content

• Overview

• Insulin

– Structure

– Synthesis

– Metabolic effects

– Mechanism of action

– Time course of insulin actions

Lecture (3) content

• Glucagon

– Metabolic effects

– Mechanism of action

• Epinephrine

– Metabolic effects

– Mechanism of action

Metabolic IntegrationMetabolic Integration22ndnd Year Nutrition Year Nutrition

By

Eman Mokbel Alissa, Ph.D.Eman Mokbel Alissa, Ph.D.

Lecture (1) content

• Major metabolic pathways

• Hormonal control• Fuel metabolism• Control of intermediates

flow through metabolic pathways

• Absorptive state• Liver

– CHO metabolism – Fat metabolism– A A metabolism

• Adipose tissue – CHO metabolism– Fat metabolism

• Resting skeletal muscle – CHO metabolism– Fat metabolism– A A metabolism

• Brain – CHO metabolism– Fat metabolism

Lecture (2) content

• Fasting state• Metabolic fuels• Enzymatic changes in

fasting state• Mechanisms involved

in switching hepaticmetabolism between the well-fed and starved state

• Postabsorptive state • Specialized tissues

• Liver – CHO metabolism– Fat metabolism

• Adipose tissue– CHO metabolism– Fat metabolism

• Resting skeletal muscle– CHO metabolism– Fat metabolism

• Brain– CHO metabolism – Fat metabolism