Last updated date: 25th Dec 2022 Show
• Total views: 182.4k • Views today: 18.20k Answer VerifiedHint: Prokaryotic cells are primitive cells mainly found in the unicellular organisms, and they do not nucleus, instead they contain a fragment of DNA, and the organelles are not bounded by the membranes, where as the eukaryotic cells are found in all types of multicellular organisms such as plant and animal cells and they contains nucleus and membrane bound organelles. Complete answer:
Note: So prokaryotes are primitive cells compared to eukaryotes and in prokaryotes both transcription and translation occurred as couple, which means that translation begins during the time of synthesis of mRNA, while in eukaryotic cells, mRNA produce in nucleus and enters the cytoplasm where translation begins freshly. Chapter 3: Introduction to Cell Structure and Function By the end of this section, you will be able to:
Cells fall into one of two broad categories: prokaryotic and eukaryotic. The predominantly single-celled organisms of the domains Bacteria and Archaea are classified as prokaryotes (pro– = before; –karyon– = nucleus). Animal cells, plant cells, fungi, and protists are eukaryotes (eu– = true). Components of Prokaryotic CellsAll cells share four common components: 1) a plasma membrane, an outer covering that separates the cell’s interior from its surrounding environment; 2) cytoplasm, consisting of a jelly-like region within the cell in which other cellular components are found; 3) DNA, the genetic material of the cell; and 4) ribosomes, particles that synthesize proteins. However, prokaryotes differ from eukaryotic cells in several ways. A prokaryotic cell is a simple, single-celled (unicellular) organism that lacks a nucleus, or any other membrane-bound organelle. We will shortly come to see that this is significantly different in eukaryotes. Prokaryotic DNA is found in the central part of the cell: a darkened region called the nucleoid. Figure 3.6 This figure shows the generalized structure of a prokaryotic cell.Unlike Archaea and eukaryotes, bacteria have a cell wall made of peptidoglycan, comprised of sugars and amino acids, and many have a polysaccharide capsule (Figure 3.6). The cell wall acts as an extra layer of protection, helps the cell maintain its shape, and prevents dehydration. The capsule enables the cell to attach to surfaces in its environment. Some prokaryotes have flagella, pili, or fimbriae. Flagella are used for locomotion, while most pili are used to exchange genetic material during a type of reproduction called conjugation. Eukaryotic CellsIn nature, the relationship between form and function is apparent at all levels, including the level of the cell, and this will become clear as we explore eukaryotic cells. The principle “form follows function” is found in many contexts. For example, birds and fish have streamlined bodies that allow them to move quickly through the medium in which they live, be it air or water. It means that, in general, one can deduce the function of a structure by looking at its form, because the two are matched. A eukaryotic cell is a cell that has a membrane-bound nucleus and other membrane-bound compartments or sacs, called organelles, which have specialized functions. The word eukaryotic means “true kernel” or “true nucleus,” alluding to the presence of the membrane-bound nucleus in these cells. The word “organelle” means “little organ,” and, as already mentioned, organelles have specialized cellular functions, just as the organs of your body have specialized functions. Cell SizeAt 0.1–5.0 µm in diameter, prokaryotic cells are significantly smaller than eukaryotic cells, which have diameters ranging from 10–100 µm (Figure 3.7). The small size of prokaryotes allows ions and organic molecules that enter them to quickly spread to other parts of the cell. Similarly, any wastes produced within a prokaryotic cell can quickly move out. However, larger eukaryotic cells have evolved different structural adaptations to enhance cellular transport. Indeed, the large size of these cells would not be possible without these adaptations. In general, cell size is limited because volume increases much more quickly than does cell surface area. As a cell becomes larger, it becomes more and more difficult for the cell to acquire sufficient materials to support the processes inside the cell, because the relative size of the surface area across which materials must be transported declines. Figure 3.7 This figure shows the relative sizes of different kinds of cells and cellular components. An adult human is shown for comparison.Section SummaryProkaryotes are predominantly single-celled organisms of the domains Bacteria and Archaea. All prokaryotes have plasma membranes, cytoplasm, ribosomes, a cell wall, DNA, and lack membrane-bound organelles. Many also have polysaccharide capsules. Prokaryotic cells range in diameter from 0.1–5.0 µm. Like a prokaryotic cell, a eukaryotic cell has a plasma membrane, cytoplasm, and ribosomes, but a eukaryotic cell is typically larger than a prokaryotic cell, has a true nucleus (meaning its DNA is surrounded by a membrane), and has other membrane-bound organelles that allow for compartmentalization of functions. Eukaryotic cells tend to be 10 to 100 times the size of prokaryotic cells. eukaryotic cell: a cell that has a membrane-bound nucleus and several other membrane-bound compartments or sacs organelle: a membrane-bound compartment or sac within a cell prokaryotic cell: a unicellular organism that lacks a nucleus or any other membrane-bound organelle What are the 3 main differences between prokaryotes and eukaryotes?Prokaryotes are always unicellular, while eukaryotes are often multi-celled organisms. Additionally, eukaryotic cells are more than 100 to 10,000 times larger than prokaryotic cells and are much more complex. The DNA in eukaryotes is stored within the nucleus, while DNA is stored in the cytoplasm of prokaryotes.
What are 5 differences between prokaryotic and eukaryotic cells?Thus, two types of cells are found in the organisms: eukaryotic and prokaryotic depending on whether cells contain membrane-bound organelles or not.
...
What is the difference between Prokaryotic and Eukaryotic Cells?. What are 4 differences between prokaryotic and eukaryotic cells?Eukaryotic cells contain membrane-bound organelles, such as the nucleus, while prokaryotic cells do not. Differences in cellular structure of prokaryotes and eukaryotes include the presence of mitochondria and chloroplasts, the cell wall, and the structure of chromosomal DNA.
What are the 3 similarities and 3 differences between prokaryotic and eukaryotic cells?Like a prokaryotic cell, a eukaryotic cell has a plasma membrane, cytoplasm, and ribosomes, but a eukaryotic cell is typically larger than a prokaryotic cell, has a true nucleus (meaning its DNA is surrounded by a membrane), and has other membrane-bound organelles that allow for compartmentalization of functions.
|