Xylorian Oculopathy - Unit 2 Bio Project

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Start

Xylorian oculopathy

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Intial Case

Disorder Overview

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Alien Cells

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Compartmentalization

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Surface Area-to-Volume

Diagnosis & Solution

The first identified Xylorian with this cellular dysfunction is a 17 year old male who had first experienced blurring and clouding vision in one eye, which then worsened into a severe loss of sharpness and color vision in both eyes. The patient has been in observation for several months, and it seems that the cause for this sudden, unexpected vision loss is hereditary mitochondrial dysfunction.

Intial case

Introduction

• All cells have four common components: a plasma membrane, cytoplasm, DNA, and ribosomes
• Prokaryotic cells lack a nucleus, membrane-bound organelles, and multiple rod-shaped chromosomes, setting them apart from eukaryotic cells which contain those
• Essentially, eukaryotic cells have a more complex structure
• Xylorians, like humans, are made up of eukaryotic cells

Prokaryotic Vs. Eukaryotic

Alien Cell Structures & Functions

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Eukaryotic Cell Info

Prokaryotic Cell

• Eukaryotic cells have internal membranes that compartmentalize the cell into specialized regions
• The endoplasmic reticulum, Golgi body, nucleus, mitochondria, lysosomes, and peroxisomes are examples of distinct compartments separated by permeable membranes
• This compartmentalization improves the efficiency of intracellular functions by allowing each organelle to perform its process and prevents potentially dangerous molecules from freely roaming the cell
• Examples of non-membrane-bound organelles are ribosomes, the cytoskeleton, and centrosomes

Compartmentalization

Membrane-Bound Structures

Eukaryotic Cell

• Most cells are approximately spherical in shape
• As the radius of a sphere increases, its surface area increases as the square of its radius, whereas its volume increases as the cube of its radius (much faster)
• This means that as a cell increases in size, its surface area-to-volume ratio decreases
• Xylorian cells are eukaryotic, and so they are on average larger than prokaryotic cells
• Larger cells, as compared to smaller cells, tend to be less efficient in the exchange of nutrients and wastes with the environment
• To make up for this deficiency, larger cells can increase their surface area by foldings of the cell membrane, become flat and elongated, or develop organelles that perform specific tasks

Surface Area-to-Volume Ratio

Surface Area-to-Volume Ratio

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Example

• It has been determined that the cause of the disorder affecting Xylorians is a mutation in the genes found in the DNA of mitochondria, an organelle that generates energy needed to power the cell
• Mutations in any of the genes associated with this disorder disrupt normal mitochondrial function, leading to a lack of energy in cells
• It remains unclear exactly how these genetic changes cause the death of cells in the optic nerve and lead to the specific features of Xylorian oculopathy

Diagnosis

The Malfunction

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Endomembrane Pathway

Solution

Mitochondria

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• Cytosol - liquid solution in which organelles are suspended
• Nucleus - stores genetic material (DNA) as chromatin; nucleolus is the site of ribosome formation
• Mitochondria - site of energy production (ATP)
• Peroxisome - metabolizes waste
• Golgi Body - involved in the transporting and modification of proteins and lipids
• Lysosome - site of the breakdown of macromolecules
• Ribosomes - responsible for protein synthesis
• Smooth Endoplasmic Reticulum - synthesizes lipids
• Rough Endoplasmic Reticulum - makes secretory and membrane proteins
• Centrosome - plays a role in cell division
• Plasma Membrane - semi-permeable and selective barrier surrounding the cell
• Cytoskeleton - maintains cell shape and internal organization

parts & Functions oF Eukaryotic Cells

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Diagram

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The endomembrane system is a group of membrane and organelles in eukaryotic cells that works together to modify, package, and transport lipids and proteins. The mitochondria, which is responsible for the disorder, is not included in this pathway.

• First, RNA is made in the nucleus from a DNA template during the process of transcription.
• That RNA moves out of the nucleus to the rough endoplasmic reticulum
• The rough ER has ribosomes on it which will then read the RNA transcript and combine different amino acids to form the protein polypeptides from the RNA instructions
• Those modified proteins will be packaged into vesicles and transported to the Golgi body to be sorted, packaged, and tagged for distribution
• Finally, the proteins will be transported by other vesicles which will either deposit their contents into other parts of the cell such as the lysosome or fuse with the plasma membrane and release their contents outside the cell

the ENdomembrane pathway

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Diagram

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• Due to how little is known about the disorder, there is no definitive cure at the moment
• However, researchers believe that gene therapy may be a promising treatment
• Gene therapy is a technique that aims to cure a disease by altering a person’s genetic makeup instead of using the more traditional methods
• For Xylorian oculopathy, the defective gene would be replaced by a healthy version of that gene

The Solution