MITOCHONDRIA AND LYSOSOMES

HUSAN BANO

Assistant Professor

Deptt. Physiology. SMC

Mitochondrial Structure (cont.)

MITOCHONDRIAL MEMBRANE

1. Outer layer2. Inner layer

Contents of outer layer:• Smooth layer containing various

enzymes.• Acetyl COA• Glycerol-phosphate-acetyltransferase

Contents of inner layer

• Have in-foldings called “cristae”.

• Cristae contains “oxidative enzymes” and “protein molecules” involved in respiration and ATP synthesis, so called “Respiratory chain” or “electron transport system”

RESPIRATORY CHAIN INCLUDES:

• Succinic dehydrogenase

• Dihydro-nicotinamide-adenin dinucleotide

(NADH).

• Cytochrome oxidase

• Cytochrome-C

• ATP synthetase

MITCHONDRIAL MATRIX

• Dissolved enzymes

• DNA

• RNA

FUNCTIONS OF MITOCHONDRIA

1. Energy Production Nutrients CO2 + H2O + Energy

2. Synthesis of ATP Used in: a. Protein synthesis b. Muscle contraction c. Ionic transport

Cont….

3. APOPTOSIS : Means “Programmed cell death”

• Under genetic control.

• Normal phenomena

• Presences of cytochrome-C

If a cell did not have mitochondria,it would be unable to:

1. move

2. produce energy

3. synthetize protein

4. synthesize enzyemes

LYSOSOMES

STRUCTURE OF LYSOMES

• They are rounded dense bodies.

• They are membrane bounded organalle

• Contains variety of “hydrolytic enzymes”

• Digest the foreign bodies.

• Most abundenly found in lungs,spleen and WBC

LYSOMES AND PEROXISOMES

LYSOSOMES

• Structure of lysomes:

FORMATION OF LYSOSOMES AND LYSOSOMAL ENZYMES

• Lysosomal enzymes produced on ribosome.

• They are channel into matrix of endoplasmic reticulum.

• Goes to golgi appratus

• Package in the form of secretory granules or “primary lysosomes”

FORMATION OF LYSOSOMES

FUNCTIONS OF LYSOSOMES

• It act as digestive system of single typical cell.

• Play an important role in removal of damage portion of cell, if the cell damage by heat, cold, trauma or chemical

FUNCTIONS OF LYSOSOMES Cont …..

• It has bactericidal action.

PEROXISOMES

• It is membrane bounded organalle.

• Also called micro bodies.

• It is formed by pinched off from ER.

• Contain “Oxidative enzymes” such as CATALASE, URATE OXIDASE and

D-AMINO ACID OXIDASE

FUNCTIONS OF PEROXISOME

1. Detoxification

2. Form the site of oxygen utilization in the cell.

3. Breakdown the excess fatty acids.

4. Accelerate gluconeogensis from fats.

5. Degrade purine to uric acid.

6. Participate in the formation of myelin and bile salts.