1. Nucleolus & Peroxisomes
Tamia Johnson & Wells Powell

2. Nucleolus
******Definition: A small, typically round granular body composed of protein and RNA in the nucleus of a cell.
It is usually associated with a specific chromosomal site and involved in ribosomal RNA synthesis and the formation of ribosomes.
**Locations: The location of the nucleolus takes place within the nucleus (Pretty self explanatory). Understand that it does not contain a nucleus and is composed of Nucleic acids and proteins.

3. Peroxisomes
Peroxisomes: A small organelle that is present in the cytoplasm of many cells and that contains the reducing enzyme catalases and usually some oxidases.
Location: Peroxisomes are membrane bound organelles found in eukaryotic cells (nucleated cells). They would be found distributed throughout the cell.

4. Plant & Animal cell locations

5. In Depth... ***** The nucleolus builds ribosomes.
Ribosomes are made up of rRNA and a protein. They may be found dispersed in the cytoplasm or attached to rough endoplasmic reticulum.
Ribosomes are essential to cell function because they build many different types of proteins through the process of DNA transcription.
For instance if it were not for transport proteins the cell could not receive essential nutrients.
Important

6. Function of Nucleolus
1.)The nucleolus disassembles at the beginning of mitosis, its components disperse in various parts of the cell and reassembly occurs during telophase and early G1 phase.
2.) Ribosome assembly begins with transcription of pre‐rRNA.
3.) During transcription ribosomal and nonribosomal proteins attach to the RNA. ***The nucleolus also contains proteins and RNAs that are not related to ribosome assembly and a number of new functions for the nucleolus have been identified.
These include assembly of signal recognition particles, sensing cellular stress and transport of HUMAN IMMUNODEFICIENCY VIRUS 1 (HIV‐1) messenger RNA.
***The nucleus has a primary function and that is to assemble ribosomes its the largest structure in the nucleus.

7. Function of Peroxisomes
***A major function of the peroxisome is the breakdown of FATTY ACID molecules, in a process called beta-oxidation.
In this process, the FATTY ACIDS are broken down two carbons at a time, converted to Acetyl-CoA, which is then transported back to the cytosol for further use.
In animal cells, beta-oxidation can also occur in the mitochondria. In yeast and plant cells, this process is exclusive for the peroxisome.

8. Why Is the nucleolus important?
***The nucleolus is responsible for producing RNA nucleotides which are important in the construction process of transcription in protein synthesis,
the nucleolus is also the site of rRNA production which is a major component of ribosomes (also involved in protein synthesis).
***Nucleolus contains the genes for three of the four classes or ribosomal RNA.
***Without these RNA, ribosomes cannot be formed and this will make the cell devoid of the platform for the formation of proteins.

9. Why is the Peroxisome Important?
**** Peroxisomes are important for lipid metabolism.
****Peroxisomes contain the first two enzymes required for the synthesis of plasmalogens.
**** Peroxisomes also play important roles in cholesterol and bile acid synthesis, purine and polyamine catabolism, and prostaglandin metabolism. In plants, peroxisomes are required for photorespiration.

10. Size and Shape of the nucleolus
The nucleolus is a small round granular cell

11. Size and shape of the peroxisomes?
The peroxisome is a small round cell that hides within the nucleus Accordingly, they are remarkably fluid and can change dramatically in abundance, size, shape and content in response to numerous cues.
These dynamics are controlled by multiple aspects of peroxisome biogenesis that are coordinately regulated with each other and with other cellular processes.

12. What Happens if the nucleolus does not work?
No ribosomes would be made and from that no proteins would be made. This is where diseases come into play

13. What happens when the peroxisomes dont work
When peroxisomes don't work diseases can start to occur because the reduction of catalases and oxidases aren't reducing fast enough so it causes a build up in the cell.

14. Diseases/ and or health problems in the nucleolus
The nucleolus is a multifunctional organelle with multiple roles involving cell proliferation, growth, survival, ribosome biogenesis and stress response signaling.
Alteration of nucleolar morphology and architecture signifies an early response to increased cellular stress.
This review briefly summarizes nucleolar response to cardiac stress signals and details the role played by nucleolar proteins in cardiovascular pathophysiology.

15. Other diseases with peroxisomes
**A peroxisome is an important part of a normal body cell like the nucleus or mitochondria.
***Two of the most common peroxisomal diseases are called Zellweger [zel´weg-er] Disease and Neonatal Adrenoleukodystrophy. (uh-dree-noh-loo-koh-dis-truh-fee)
In these two diseases, the patient has defects in the process of making bile acids because some of the steps occur within the peroxisome part of the cell. These diseases affect many organs in the body.
This is because peroxisomes occur in cells throughout the body. In peroxisomal diseases, the liver disease can vary in severity. These diseases can also include problems in the brain, including mental retardation, convulsions, deafness, blindness, and muscle weakness.

16. Research and studying of Nucleolus
****Recent studies suggest that the mammalian nucleolus may also play roles in tumorigenesis, viral replication and cellular stress sensing. However, the pathway and the identities of the molecular machineries involved in these mechanisms within this nuclear organelle remain largely unknown.
***In addition to its major role in ribosome production, the nucleolus may also be involved in messenger RNA (mRNA) export or degradation
Mammalian nucleolus

17. Research and Studying of Peroxisomes
More than half a century of research on peroxisomes has revealed unique features of this ubiquitous subcellular organelle, which have often been in disagreement with existing dogmas in cell biology.
About 50 peroxisomal enzymes have so far been identified, which contribute to several crucial metabolic processes such as β-oxidation of fatty acids, biosynthesis of ether phospholipids and metabolism of reactive oxygen species, and render peroxisomes indispensable for human health and development.

18. Work Cited
Wanders, R. J.; Waterham, HR. R. (2006). "Biochemistry of Mammalian Peroxisomes Revisited". Annual Review of Biochemistry 75: 295–332.doi: /annurev.biochem PMID edit
Jump up^ Wanders, R.; Waterham, H. (2006). "Peroxisomal disorders: the single peroxisomal enzyme deficiencies". Biochimica et Biophysica Acta (BBA) - Molecular Cell Research 1763: doi: /j.bbamcr edit
Jump up^ Weller, S.; Gould, S. J.; Valle, D. (2003). "Peroxisome Biogenesis Disorders". Annual Review of Genomics and Human Genetics 4: 165–211.doi: /annurev.genom PMID edit
Alberts B, Johnson A, Lewis J, et al. Molecular Biology of the Cell. 4th edition. New York: Garland Science; Peroxisomes. Available from: