Case Study: Cells
BIOS 251 Week 3 Case Study Assignment: Cells (GRADED A+)
BIO251 Anatomy and Physiology
1. Brian indicates that the mutati
...
Case Study: Cells
BIOS 251 Week 3 Case Study Assignment: Cells (GRADED A+)
BIO251 Anatomy and Physiology
1. Brian indicates that the mutation is in a gene found in the mitochondrial DNA. What does Brian mean by that and why did he signify mitochondrial DNA?
The mutation found in the gene in the mitochondrial DNA is because mitochondria produces much of the energy that cells need to function. In the mitochondrial DNA, which is separate from the DNA of the cell, is affected by the gene mutations, MT-ND1, MT-ND4, MT-ND4L and MT-ND6 in LHON. These inherited mutations disrupt the mitochondria and cause death cells in the retina of the eye.
2. What is the main function of the mitochondria within the cells?
Mitochondria are the “powerhouses” of the cell. The main function of the mitochondria within the cell is to produce energy, by extracting organic compounds and then transferring it to ATP, mostly by enzymes located on the cristae.
3. Describe the composition of the mitochondrial membrane and compare that with the composition of a eukaryotic cell membrane. What are the functions of cell membranes?
The mitochondria is surrounded by a double unit membrane. The outer layer covers the surface of the mitochondria. The inner membrane usually contains folds that are known as cristae, which provide a large amount of area for chemical reaction to happen. The space in between the cristae called the matrix contains ribosomes, enzymes used in ATP synthesis and a small round DNA molecule known as the mitochondrial DNA. The eukaryotic cell is said to be a true nucleus, because the cell is surrounded by a membrane. It is a membrane-bound nucleus that includes several membrane-bound organelles such as the endoplasmic reticulum, golgi apparatus, chloroplasts, and mitochondria. The function of cell membranes includes the protection of the cell by boundaries, controls its interactions with other cells, and controls the passage of materials into and out of the cell. The intracellular part of the membrane faces the cytoplasm, and the extracellular faces outward.
4. Although it is unclear how defects in the mitochondria can cause cell death in the optic nerve, what would be your hypothesis on how this can happen knowing the function of the mitochondria within the cell?
My hypothesis is that since mitochondrial DNA is exposed to damage from the free radicals normally generated in mitochondria by aerobic respiration that mitochondrial DNA has no effective mechanism for repairing damage, that's why it mutates more rapidly than nuclear DNA. The people who have LHON are not able to produce energy in the mitochondria and that's what leads to the gene mutation that leads to the damage of the optic nerve known as optic atrophy.
References
About LHON. LHONsociety.org :: About LHON.(2018). http://lhonsociety.org/about-lhon/.
Boundless. (2021). Boundless Biology. Lumen. https://courses.lumenlearning.com/boundless-biology/chapter/eukaryotic-cells/.
Leber hereditary optic neuropathy (LHON). Fighting Blindness. (2019, August 26). https://www.fightingblindness.ie/living-with-sight-loss/eye-conditions/leber-hereditary-opti c-neuropathy-lhon/#:~:text=Treatment-,Description,that%20reside%20within%20the%2ell.
Saladin, K. S. (2007). In Anatomy & physiology: the unity of form and function
(pp. 116,121). essay, McGraw-Hill.
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