Peroxisomes and glyoxysomes, Biology

Assignment Help:

PEROXISOMES AND GLYOXYSOMES

Certain small ovoid  unit membrane bound  sac like  cytoplasmic  organelles, resembling  lysosomes in size  and appearance  were  isolated  from various types of animals  and plant cells  by due Duve 1965 these however differ from  lysosomes in being  formed  by budding  from smooth endoplasmic   reticulum and containing not hydrolysing but mainly certain oxidative enzyme oxidases. D amino  acid oxidase and  urate  oxidase .These  enzyme  catalyse  oxidation  of amino uric and  lactic acids  to synthesize  hydrogen  peroxide (H2O2) and  catalase  enzyme  which  decomposes H2O2 .That  is why these organelles  were  christened peroxisomes  probably these correspond  to microbodies  detected carlier 1954 Rhodin   by electron  microscopy.  Later  it was  found that  some peroxisomal  enzyme are related to the biosynthesis  of certain components  of cellular membranes .In  plant cells  peroxisomes co operate with chloroplasts  in the   process  of photo respiration.

 The number of peroxisomes per cell varies from 70 to100.  How and where  these are formed in the cells is not yet clearly understood. Possibly , these form  as buds from  cytoplasmic  reticulum  but  their  enzyme  are synthesized  by ribosomes   found free in the cytosol peroxisomes have  brief  life  span of 5 to6 days .Hence,  old ones are regularly  dissolved by autophagy and  new  ones are formed.

Glyoxysomes : are organelles similar  to peroxisomes   but contain enzyme  of  glyoxylate cycle  which  is concerned  with conversion  of fats to sugars. These occur in cells of fungi,  some protista  and germinating seeds. 


Related Discussions:- Peroxisomes and glyoxysomes

Define tests of cardiovascular endurance, Define Tests of Cardiovascular E...

Define Tests of Cardiovascular Endurance? Cardiovascular endurance or aerobic fitness is the ability to exercise continuously for extended periods without tiring. It can be me

What is tree girdling, What is tree girdling? What happens to a plant when ...

What is tree girdling? What happens to a plant when that girdle is removed from the stem (below the branches)? Malpighi's girdling, or tree girdling, is the removal from a ste

Explain the completed test - most probable number test, Explain the Complet...

Explain the Completed Test - Most Probable Number Test? Coliform colonies on EMB or Endo agar are further examined by completed test by inoculating lactose broth and nutrient a

Describe the use of sorbates acid in microorganisms, Q. Describe the use of...

Q. Describe the use of Sorbates acid in Microorganisms? Sorbic acid is an unsaturated carboxylic acid whose salts as sodium, calcium or potassium are used in foods upto

People who are at risk from drug-nutrient interactions, Determine People wh...

Determine People who are at risk from drug-nutrient interactions? People who are at risk from drug-nutrient interactions are the: 1. Persons who have a poor diet or in other

Skeleton, what are the biological significance of skeleton

what are the biological significance of skeleton

Feline leukemia, Feline leukemia The disease is caused by a retrovirus and...

Feline leukemia The disease is caused by a retrovirus and is the most common naturally occurring lymphosarcoma and accounts for nearly 30% of feline tumors. Based on the location

Describe excretory system of annelids, Q. How be able to the excretory syst...

Q. How be able to the excretory system of annelids be described? In each segment (metamere) of the being a pair of complete excretory structures known as metanephridium exists.

Define preterm and low birth weight, Define Preterm and Low Birth Weight? ...

Define Preterm and Low Birth Weight? The foetal and neonatal health is mainly dependent on the birth weight and it has been well recognized that perinatal (from birth upto one

What is technetium 99m sestamibi scan, Q. What is Technetium 99M Sestamibi ...

Q. What is Technetium 99M Sestamibi Scan? This study is another form of studying perfusion of the heart. This radioactive study is similar to that of thallium 201. With a combi

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd