only respond to post 1 and 2
(topic of discussion
Prokaryotic and eukaryotic are the two major categories of cells making up life on earth. Both these types require water and carbon.
Describe the characteristics of water and carbon that makes them important to living things in general, and to specific forms of life including plants, animals, and prokaryotes. Why is NASA looking for water on Mars?
Describe the differences in prokaryotic and eukaryotic cells. How have the characteristics of each kind of cell put limitations and provided opportunities for the survival and divergence of modern living things? Why might both cell types be considered equally successful? Make sure to consider both Domains of Prokaryotes.)
The characteristics of water that make it important to living things in general are the structure of the water molecule, polarity, and the hydrogen bonding. The cohesion of water is waters ability to stick together with hydrogen bonding to other hydrogen molecules. Trees use the cohesion of water to help transport it from the roots to the leaves. Cohesion in water is more prominent than with most other liquids. Water has a higher surface tension than other liquids, which is the measure of how difficult it is to stretch or break the surface of a liquid. Insects and spiders can walk on water without breaking the surface because the hydrogen bonds are so strong. Water has a stronger resistance to temperature change because of hydrogen bonding. When the temperature of water is rising, hydrogen bonds are being broken, and the water stores large amounts of heat, while only changing by a few degrees. Hydrogen bonds are broken before water heats up. Therefore, water does not heat up as quickly as other substances. When water cools and starts forming ice, hydrogen bonds are being made. Water releases the stored heat before it drops a few degrees. Earth’s water supply regulates the temperature by storing the heat from the sun during warm seasons and releasing heat during the cold seasons. Landlocked areas have a greater temperature fluctuation and coastal areas have milder temperature changes. Another way water releases heat is by evaporative cooling. This occurs when the molecules of water that have the most heat vaporize, leaving the surface cooler. This also happens in animals through the ability to sweat. When water freezes over a body of water, such as an ocean or lake, it creates an insulating layer of ice on top of the water. This allows life to continue under the ice, without completely freezing. Water acts as a medium for chemical reactions because many different solutes can be dissolved in water. NASA is looking for water on Mars because it would mean Mars is capable of supporting life.
Carbon is important to life because it has four open spots to form bonds with other molecules, thus becoming the building blocks of life. Carbohydrates, proteins, and nucleic acids, including DNA are macromolecules. They are polymers, large molecules made from smaller molecules called monomers strung together. The monomers connect through a dehydration process. Two hydrogen molecules and one oxygen molecule are released from the reactants. The breakdown of polymers is the opposite of the dehydration process, called hydrolysis. For example, in our bodies, this occurs when we break down protein and carbohydrates to be used in our cells. Carbohydrates are a group of molecules that include sugars and polymers of sugars. For animals, they are an energy source and for plants, they are the building material for most of the plant structure. Monosaccharides or simple sugars are monomers of carbohydrates and cannot be broken down into smaller sugars. Glucose and fructose have the same formula, but the atoms are arranged differently, and they are called isomers. Isomers have different properties, such as the taste difference between glucose and fructose. Disaccharides are double sugars connected through the dehydration process. Polysaccharides are complex sugars, made from long chains of polymers of monosaccharides. An example is starch. Plants store starch as a stockpile that can be tapped when needed.
The main differences between prokaryotic cells and eukaryotic cells are the size and nucleus. Prokaryotes are single celled and do not have a membrane bound nucleus. They are smaller in size and have no internal membranes. Prokaryotes can have large populations in smaller areas because of the size and their rapid reproduction. Mutations within these cells can develop quickly because of the rapid reproduction and some types can even pass genetic material to one another. Eukaryotes are much larger and have a membrane bound nucleus. They also have internal compartmentalization using membranes. Eukaryotes can either be single celled or form multicellular organisms and they have a complex structure. Eukaryotes can store food and resources and they have isolation and control of physiological processes. There is a greater diversity of processes within the cell because they have a nucleus and organelles. Because eukaryotic cells reproduce sexually, they have a greater genetic diversity.
The characteristics of prokaryotes have put limitations of genetic diversity because they reproduce asexually. The rapid reproduction is an opportunity to survive and thrive because the cells can possibly reproduce faster than the environment can destroy them. Eukaryotes are limited to sexual reproduction that is a slower process than that of the prokaryotes. Eukaryotes are more genetically diverse because of sexual reproduction. Both cell types can be considered equally successful because they are both surviving in today’s ever-changing environment. Archaea can survive in extreme environments and bacteria can grow almost anywhere. Eukaryotes have mutated and adapted to survive in almost any climate, as different animals.
Eric J. Simon, Jean L. Dickey, Jane B. Reece, and Kelly A. Hogan. (2016). Campbell Essential Biology, 5th Ed. Benjamin-Cummings Publishing Company
Water and carbon are important to living things, plants, animals and prokaryotes because they are necessary for reproduction, growth and survival. Regardless of where you are in the world, no matter the climate or environment, you will always see water in its three forms whether it be gas, solid or liquid. There are four groups that carbon can bond with in order for living things to be functional. All living things are dependent upon water and carbon. NASA is looking for water on Mars in order for Mars to be livable, just as Earth is. Of all the cells there are, which is innumerable, they are either prokaryotic cells or eukaryotic cells. Though they have a few comparations, they contrast in a number of ways. To begin, it is said that prokaryotic cells have been around longer than eukaryotic cells according to indication from fossils. Of the two, eukaryotic cells are greater in size and also have organs, in which prokaryotic cells do not. Instead of a nucleus, prokaryotic cells have a nucleoid. The structure of the two are also different. As described in our textbook, a prokaryotic cell is like an open warehouse, as opposed to a eukaryotic cell which is like an office building with cubicles Eric J. Simon, Jean L. Dickey, Jane B. Reece, and Kelly A. Hogan. (2016). Campbell Essential Biology, 5th Ed. The characteristics of the prokaryotic cells causes limitations because they can’t perform numerous roles. The characteristics of the eukaryotic cells cause limitations because of how large they are in size. In contrast, both cell types may be considered equally successful because they are both required to live.