Question

1. A cell must continuously sort useful materials from its waste products and then remove or recycle the waste. One way a cell does this is to first put tiny tags on proteins that are no longer needed. These tags, which are small polypeptide chains 76 amino acids long, are called ubiquitin.
2. Ubiquitin tags direct proteins to compartments of the cell called proteasomes. Within each proteasome, ubiquitin-tagged proteins are deconstructed into their component amino acids. These pieces can be repurposed to build new proteins.

3. Sometimes organs stop processing waste effectively, allowing the waste to pile up and contributing to many diseases. Alzheimer's disease, for example, includes piles of waste proteins in the brain called tangles, while Parkinson's disease involves the accumulation of recyclable material into Lewy bodies. Mallory bodies are piles of waste proteins common in liver disease. These piles, known generically as inclusions, can be identified under the microscope because they are covered in tiny ubiquitin tags.

4. A problem in the breakdown of ubiquitin-tagged proteins may be one cause of spinocerebellar ataxia type 1. In this disease, a protein called ataxin-1 has an abnormal genetic mutation, and ubiquitin is able to attach to the mutant protein. Scientists believe that the mutated protein cannot be chopped up by the proteasome because of its shape, so ubiquitin-tagged ataxin-1 starts to accumulate, which leads to cell death. The cells most affected by this genetic mutation are neurons in a part of the brain associated with motor control and the spinal cord. So, a person with mutant ataxin-1 progressively loses muscle control as these cells die.


Which phrase describes the purpose of ubiguitin

A. to tag waste proteins for recycling in the proteasomes

B. to create small polypeptide chains that are 76 amino acids long

C. to create inclusions that can be identified under the microscope

D. to attach to mutant proteins so that they can accumulate In the cell


If proteins contain mutations, the proteins often do not maintain the proper shape and are unable to perform their functions. Properly functioning proteins are essential to maintaining healthy organisms.

Which statement describes the overall consequence of proteins containing mutations like those described in the passage?

A. Wastes will build up and will be reassembled to build new proteins.

B. Wastes will build up, and Mallory bodies will accumulate in the liver.

C. Wastes will build up in cells and will eventually be excreted from each cell.

D. Wastes will build up in vital organs, and the organism will experience disease.


Why do individuals with spinocerebellar ataxia experience loss of muscle control, even though the ataxin-1 protein builds up only In the brain and spinal cord?

A. Inclusions can build up in all body systems and can cause debilitating effects.

B. Genetic mutations in the ataxin-1 protein cause muscular proteins to change shape.

C. When the ubiquitin tagging system does not work effectively, cellular waste can build up in the muscles.

D. The neurons affected by the ataxin-1 protein buildup are in a region of the brain that manages muscle control.

Answer 1

Based on the role of ubiquitin in protein deconstruction as stated in the passage, the correct options are as follows:

1. to tag waste proteins for recycling in the proteasomes; option A.
2. Wastes will build up in vital organs, and the organism will experience disease; option D
3. the neurons affected by the ataxin-1 protein buildup are in a region of the brain that manages muscle control; option D.

What are phrases?

Phrases refers to a group of words which contains a verb but which on their own do not make complete sense.

In the description of the role of Ubiquitin, it is described as a small polypeptide chain containing 76 amino acids. The main tole of ubiquitin is to tag proteins for deconstruction in the proteasomes.

Therefore, the phrase describes the purpose of ubiquitin is to tag waste proteins for recycling in the proteasomes; option A.

Based on the passage, the statement that describes the overall consequence of proteins containing mutations is: Wastes will build up in vital organs, and the organism will experience disease; option D

Individuals with spinocerebellar ataxia experience loss of muscle control, even though the ataxin-1 protein builds up only in the brain and spinal cord because the neurons affected by the ataxin-1 protein buildup are in a region of the brain that manages muscle control; option D.

In conclusion, mutations in ubiquitin-tagged proteins will result in accumulation in the body since they cannot be deconstructed in the proteasomes.

Learn  more about ubiquitin at: brainly.com/question/27951044

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