Peroxisomes are organelles found in the cytoplasm of almost all eukaryotic cells that are involved in many important metabolic functions. They contain enzymes for fatty acid oxidation and breakdown of hydrogen peroxide. Mutations in peroxisome genes can cause serious diseases by disrupting these metabolic pathways. While peroxisomes produce their own enzymes, the genes for these enzymes are located in the cell nucleus. The enzymes are transported to peroxisomes with the help of targeting sequences and receptor proteins.

1. TITLE :
PEROXISOMES

2. WHAT SHOULD WE KNOW ABOUT PEROXISOMES ?
1. WHAT IS PEROXISOMES ?
2. STRUCTURE OF PEROXISOMES ?
3. WHERE IT IS LOCATED ?
4. WHAT IS THE FUNCTION ?
5. WHAT ARE THE IMPORTANT PROTEINS ?

3. WHAT SHOULD WE KNOW ABOUT PEROXISOMES ?
1. HOW IT WORKS ?
2. WHAT ARE THE DISEASE ?
3. PEROXISOMES IN OUR IMMUNE SYSTEM ?
4. ABOUT GLYOXSOMES ?

4. WHAT IS PEROXISOMES ?
• IT LOOKS LIKE VESICLE OR SAC LIKE ORGANELLE.
• IT IS ALSO CALLED LIPID RECYCLER .
• THE SIZE IS 0.5 MICRO METER.
• IT IS PRODUCED BY ENDOPLASMIC RETICULUM (ER).
• THE ORGAN THAT PEROXISOMES ARE ABUNDANT IN IS THE
LIVER AND KIDNEY .

5. WHAT IS PEROXISOMES ?
• EACH CELL CONTAIN 100 OR MORE THAN PEROXISOMES .
• IT IS PRESENT IN BOTH ANIMAL AND PLANT CELL .
• IT CONTAINS MORE THAN 50 ENZYMES .
• THEY ARE SELF REPLICATING .
• EACH PEROXISOMES IS A SINGLE MEMBRANE .
• THEY RESEMBLE LIKE LYSOSOME BUT ARE NOT THE SAME .

6. PEROXISOMES STRUCTURE

7. WHERE IT IS LOCATED ?
• PEROXISOMES ARE FOUND IN ALMOST ALL EUKARYOTIC CELLS.
• MAINLY LOCATED IN “CYTOPLASM”.
• THE PEROXISOME LOCATION IS IN THE CYTOPLASM OF EUKARYOTIC CELLS ,
MOST OFTEN NEAR THE ENDOPLASMIC RETICULUM AND MITOCHONDRIA.
• THE ENDOPLASMIC RETICULUM IS AN ORGANELLE RESPONSIBLE FOR PROTEIN
AND LIPID SYNTHESIS.
• MITOCHONDRIA ARE THE MAIN ORGANELLES FOR ENERGY PRODUCTION.

8. WHAT ARE THE FUNCTIONS ?
• CATABOLISM OF VERY LONG CHAIN FATTY ACIDS , BRANCH FATTY ACIDS ,
AMINO ACIDS , POLYMERS AND ETC……
• DECOMPOSITION OF H2O2 (REACTIVE OXYGEN SPECIES). POTENTIALLY
DANGEROUS PRODUCT OF FATTY ACID OXIDATION . IT IS CATALYZED BY THE
ENZYME CATALASE .
• H2O2 - HYDROGEN PEROXIDE .
• BIO SYNTHESIS OF PLASMALOGENS .
• PRODUCTION OF ACETYL CO-A ( IT IS A COMPOUND) .

9. THE FUNCTIONS.
• PARTICIPATE IN THE SYNTHESIS OF CHOLESTEROL .
• PARTICIPATES IN THE SYNTHESIS OF BILE ACIDS .
• PARTICIPATE IN THE SYNTHESIS OF LIPIDS USED TO MAKE MYELIN .
• IT BREAKDOWN OF EXCESS PURINES ( AMP , GMP ) TO URIC ACID .
• MOST OF ANIMALS USE PEROXISOMAL OXIDASE TO CONVERT URIC
ACID A PRODUCT OF THE BREAKDOWN OF NUCLEOTIDES ( PURINES
).

10. WHAT IS PURINES ?
• PURINES ACT AS
1. METABOLIC SIGNALS
2. PROVIDE ENERGY
3. CONTROL CELL GROWTH
4. PART OF ESSENTIAL COENZYMES
5. CONTRIBUTE SUGAR TRANSPORT
6. DONATE PHOSPHATE GROUPS IN PHOSPHORYLATION REACTION

11. WHAT IS AMP , GMP , IMP ?
• AMP - ADENOSINE MONOPHOSPHATE .
• GMP – GUANOSINE MONOPHOSPHATE .
• IMP - INOSINE MONOPHOSPHATE .
• THE IMP IS THE PRECURSOR OF PURINES NUCLEOTIDES AMP & GMP .
• WHAT IS AMP IN CELLS ?
• ONE OF THE COMPONENT OF RNA AND ALSO ORGANIC COMPONENT OF ENERGY
CARRYING MOLECULE ATP .
• IN CERTAIN VITAL METABOLIC PROCESS , AMP COMBINES WITH INORGANIC PHOSPHATE
TO FORM ADP (ADENOSINE DIPHOSPHATE ) .

12. WHAT ARE THE IMPORTANT PROTEINS ?
1. PTS ( PEROXISOME TARGETING SEQUENCE ) .
2. PEX RECEPTOR HELPS FOR TRANSPORT .
3. OXIDASE AND CATALASE - CONVERSION OF HYDROGEN PEROXIDE INTO
WATER AND OXYGEN .
H202 ------ H2O + O2
4. URATE OXIDASE / URICASE - OXIDASE URIC ACID.
• ABSENT IN HUMANS AND IT IS PRESENT IN RAT , REPTILES .
• IT IS PRESENT IN A CRYSTALLINE FORM .

13. HOW IT FUNCTION ?
• PEROXISOME IS A LIPID BILAYER ORGANELLE WITH URIC ACID CRYSTALLINE .
• ONLY PROTEINS PRESENT INSIDE THE PEROXISOME.
• OTHER ORGANELLES LIKE MITOCHONDRIA , CHLOROPLAST PRODUCE THERE
OWN ENZYMES BY THEIR OWN GENE .
• BUT PEROXISOMES THE ENZYME GENE PRESENT INSIDE THE NUCLEUS AND
AFTER CODING ONLY THE ENZYME WILL COME OUT .
• GENE RESPONSIBLE FOR PEROXISOME ENZYMES ARE R PRODUCED IN NUCLEUS
ONLY .

14. HOW IT FUNCTION ?
• TRANSFERRED TO ER .
• ER CONVERTS ENZYMES INTO PROTEINS BY FOLDING THEM .
• PTS ATTACHED TO IT .
- ACT AS GUIDE TO PEROXISOMES .
• PTSR (RECEPTOR ) BIND WITH ENZYME AND OPEN THE PEX 17 CHANNEL IN
PEROXISOME .
• PTSR WILL ACT AS DOOR OPENER FOR ENTERING ENZYMES INSIDE .

15. HOW IT FUNCTION ?
• BIO MOLECULES ARE BROUGHT INTO THE PEROXYSOME AND CATABOLIZED .
• THERE ARE MANY TYPES OF ENZYMES
1. PEX – 5
2. PEX – 7
3. PEX – 1
4. PEX - 2

16. WHAT ARE THE DISEASE ?
1. MUTATION IN PEX GENES (1,2,3,5,6,7) . MUTATION OCCURRED IN PEX GENE
1AND 6 .
• CAUSES ZELLWEGER SYNDROME  IT IS A NEUROLOGICAL PROBLEM .
• CAUSES HEIMIER SYNDROME  IT AFFECTS THE TRANSPORTER PROTEINS .
2. MUTATION IN PHYH ( PHYTANOYL – COA HYDROXYLASE GENE )
• CAUSES REFSUM DISEASES  ACCUMULATION OF FATTY ACIDS .

17. WHAT ARE THE DISEASE ?
1. ACATALASEMIA
• PATIENT IN THIS CASE HAVE VERY LOW CATALYSE ACTIVITY AND MANY OF
THEM DEVELOP ULCERS IN THEIR MOUTH ESPECIALLY AROUND THE TEETH.
• THIS LEADS TO DEATH
• IN ADDITION TO GENETIC DISEASE PEROXISOMES CAN BE INVOLVED IN
CANCERS A DIVERSE SET OF CHEMICALS SUCH AS DRUGS USED TO LOW BLOOD
LIPIDS , HERBICIDES , ANALGESICS AND PLASTICIZERS CAUSE THE
PROLIFERATION OF LIVER PEROXISOMES .

18. PEROXISOMES IN IMMUNE SYSTEM .

19. GLYOXSOMES
• IT IS PRESENT IN ONLY PLANT CELL .
• THE FUNCTION IS IT CONVERTS FATS INTO SUGARS .
• THE CONVERTED SUGARS WILL HELP FOR THE SEED GERMINATION TO GROW A
COMPLETE PLANT .
• THE FUNCTIONS ARE SIMILAR TO THE PEROXISOMES .

20. THANK YOU .
BY
SANJAI K