Free Essays on Worldly Challenges

As The World Grows So Do Our Challenges As the world grows so do our challenges. Not only are our problems growing in number but they are also growing in complexity. There is scarcely a day that goes by when I don't hear about some new problem that will soon threaten us all. While some of these problems such as El Nino, earthquakes, and other natural disasters cannot be stopped there are other challenges such as the spread of racial hatred, rising risk of disease spread, and the growing levels of civil unrest throughout much of the world which threaten many lives everyday. Most of the future's challenges will only be made possible if all people, regardless of race, color, or nationality, attempt to work together for a stronger world. There are many ways in which I believe that I can help society meet this future challenge of coming together as a united world. While I was an exchange student, I saw the world from a different point of view. For the first time, I realized that the people of the world have so many similarities in comparison to the few and insignificant differences. To make the people of the world unite would merely take time in convincing people of the world that we are all in pursuit of the same basic goals. All that it would take to show that this could be done is two different cultures to unite and then the rest of the world what can come by the strength all gain by coming together. I believe that I can help in solving some of the barriers that hold us back from completing the task that we all desire which is unity. I served as a miniature version of a diplomat when I was an exchange student. I helped people in another country see that we all have common goals and I also helped sever the bonds to racial hatred by providing them insight into the American way of thinking and they did likewise for me. I have done everything to help sever these ancient bonds and will continue... Free Essays on Worldly Challenges Free Essays on Worldly Challenges As The World Grows So Do Our Challenges As the world grows so do our challenges. Not only are our problems growing in number but they are also growing in complexity. There is scarcely a day that goes by when I don't hear about some new problem that will soon threaten us all. While some of these problems such as El Nino, earthquakes, and other natural disasters cannot be stopped there are other challenges such as the spread of racial hatred, rising risk of disease spread, and the growing levels of civil unrest throughout much of the world which threaten many lives everyday. Most of the future's challenges will only be made possible if all people, regardless of race, color, or nationality, attempt to work together for a stronger world. There are many ways in which I believe that I can help society meet this future challenge of coming together as a united world. While I was an exchange student, I saw the world from a different point of view. For the first time, I realized that the people of the world have so many similarities in comparison to the few and insignificant differences. To make the people of the world unite would merely take time in convincing people of the world that we are all in pursuit of the same basic goals. All that it would take to show that this could be done is two different cultures to unite and then the rest of the world what can come by the strength all gain by coming together. I believe that I can help in solving some of the barriers that hold us back from completing the task that we all desire which is unity. I served as a miniature version of a diplomat when I was an exchange student. I helped people in another country see that we all have common goals and I also helped sever the bonds to racial hatred by providing them insight into the American way of thinking and they did likewise for me. I have done everything to help sever these ancient bonds and will continue...

Ribosomes and Protein Assembly

Ribosomes and Protein Assembly There are two major types of cells: prokaryotic and eukaryotic cells. Ribosomes are cell organelles that consist of RNA and proteins. They are responsible for assembling the proteins of the cell. Depending on the protein production level of a particular cell, ribosomes may number in the millions. Key Takeaways: Ribosomes Ribosomes are cell organelles that function in protein synthesis. Ribosomes in plant and animals cells are larger than those found in bacteria.Ribosomes are composed of RNA and proteins that form ribosome subunits: a large ribosome subunit and small subunit. These two subunits are produced in the nucleus and unite in the cytoplasm during protein synthesis.Free ribosomes are found suspended in the cytosol, while bound ribosomes are attached to the endoplasmic reticulum.Mitochondria and chloroplasts are capable of producing their own ribosomes. Distinguishing Characteristics Structure of a Ribosome. Interaction of a ribosome with mRNA.   ttsz/iStock/Getty Images Plus Ribosomes are typically composed of two subunits: a large subunit and a small subunit. Eukarotic ribosomes (80S), such as those in plant cells and animal cells, are larger in size than prokaryotic ribosomes (70S), such as those in bacteria. Ribosomal subunits are synthesized in the nucleolus and cross over the nuclear membrane to the cytoplasm through nuclear pores. Both ribosomal subunits join together when the ribosome attaches to messenger RNA (mRNA) during protein synthesis. Ribosomes along with another RNA molecule, transfer RNA (tRNA), help to translate the protein-coding genes in mRNA into proteins. Ribosomes link amino acids together to form polypeptide chains, which are further modified before becoming functional proteins. Location in the Cell Ribosomes can be found attached to the endoplasmic reticulum or free within the cytoplasm.   ttsz/iStock/Getty Images Plus There are two places where ribosomes commonly exist within a eukaryotic cell: suspended in the cytosol and bound to the endoplasmic reticulum. These ribosomes are called free ribosomes and bound ribosomes respectively. In both cases, the ribosomes usually form aggregates called polysomes or polyribosomes during protein synthesis. Polyribosomes are clusters of ribosomes that attach to a mRNA molecule during protein synthesis. This allows for multiple copies of a protein to be synthesized at once from a single mRNA molecule. Free ribosomes usually make proteins that will function in the cytosol (fluid component of the cytoplasm), while bound ribosomes usually make proteins that are exported from the cell or included in the cells membranes. Interestingly enough, free ribosomes and bound ribosomes are interchangeable and the cell can change their numbers according to metabolic needs. Organelles such as mitochondria and chloroplasts in eukaryotic organisms have their own ribosomes. Ribosomes in these organelles are more like ribosomes found in bacteria with regard to size. The subunits comprising ribosomes in mitochondria and chloroplasts are smaller (30S to 50S) than the subunits of ribosomes found throughout the rest of the cell (40S to 60S). Ribosomes and Protein Assembly Ribosomes interact with mRNA to produce proteins in a process called translation.   ttsz/iStock/Getty Images Plus Protein synthesis occurs by the processes of transcription and translation. In transcription, the genetic code contained within DNA is transcribed into an RNA version of the code known as messenger RNA (mRNA). The mRNA transcript is transported from the nucleus to the cytoplasm where it undergoes translation. In translation, a growing amino acid chain, also called a polypeptide chain, is produced. Ribosomes help to translate mRNA by binding to the molecule and linking amino acids together to produce a polypeptide chain. The polypeptide chain eventually becomes a fully functioning protein. Proteins are very important biological polymers in our cells as they are involved in virtually all cell functions. There are some differences between protein synthesis in eukaryotes and prokaryotes. Since eukaryotic ribosomes are larger than those in prokaryotes, they require more protein components. Other differences include different initiator amino acid sequences to start protein synthesis as well as different elongation and termination factors. Eukaryotic Cell Structures This is a diagram of an animal cell. colematt/iStock/Getty Images Plus   Ribosomes are only one type of cell organelle. The following cell structures can also be found in a typical animal eukaryotic cell: Centrioles - help to organize the assembly of microtubules.​Chromosomes - house cellular DNA.​Cilia and Flagella - aid in cellular locomotion.​Cell Membrane - protects the integrity of the interior of the cell.​Endoplasmic Reticulum - synthesizes carbohydrates and lipids.​Golgi Complex - manufactures, stores and ships certain cellular products.​Lysosomes - digest cellular macromolecules.​Mitochondria - provide energy for the cell.​Nucleus - controls cell growth and reproduction.Peroxisomes - detoxify alcohol, form bile acid, and use oxygen to break down fats. Sources Berg, Jeremy M. Eukaryotic Protein Synthesis Differs from Prokaryotic Protein Synthesis Primarily in Translation Initiation. Biochemistry. 5th Edition., U.S. National Library of Medicine, 2002, www.ncbi.nlm.nih.gov/books/NBK22531/#_ncbi_dlg_citbx_NBK22531.Wilson, Daniel N, and Jamie H Doudna Cate. The structure and function of the eukaryotic ribosome. Cold Spring Harbor Perspectives in Biology vol. 4,5 a011536. doi:10.1101/cshperspect.a011536