Why do marine organisms living in polar regions have a very high proportion of cholesterol....?
Polar region means it's really cold because they have to swim in ice water. Cell membranes have phospholipids and cholesterol. The membrane is very fluid and it moves around. If it gets too cold, the movement would slow down. Animals would die if their cell fluidity is impaired. Cholesterol helps the fluidity of the cell membrane. Higher the amount of cholesterol in cell membrane, the more fluid the membrane becomes. That way, cholesterol keeps the cell fluidity going.
Why do marine animals living in polar regions tend to have high ratios of cholesterol?
I would imagine that they would need thicker layers of fat to insulate them from the extreme cold, so its how nature has adapted them
Suggest why marine organisms living in polar regions have a very high proportion of cholesterol in their?
The first answer is wrong. Fat is for the insulation of the whole organism. Cholesterol in the membrane keeps it fluid by disrupting the regular phospholipid structure. The cholesterol stops the cell membrane from "freezing".
Why marine organisms living in polar regions have a very high proportion of cholesterol in their membranes?
Cholesterol increases fluidity of membranes. At low temperatures, more cholesterol is necessary to prevent the membrane from becoming too inflexible.
Why is it that oil formation is high in gulf regions? Is it a mere coincidence?
It's true that many gulfs are productive oil basins, and the reason is because they are just that -- basins. An area rivers drain into can eventually form quality oil reservoirs due to the deposition of silts and sands as the river enters the sea. Over geologic time as the river deltas move and sea levels rise and fall, well-defined stratigraphic layers can be laid down. The deep organic matter layers are the source of the hydrocarbons. The sands/silts form layers of permeable reservoir rock. Clays and evaporated salt form trap rock layers to cap it all in. This is not the only way oilfields form, but it is a common one. In fact a great many land-based oilfields used to be shallow seas like this. The oil-rich gulfs today are the basins that stayed below sea level through the past few tens/hundreds of millions of years of tectonic drift. On the other hand, geologically-newer gulfs will not contain the deep layers necessary for oil. Also see the: How does plant biomass get buried and form crude oil?
Is ethanol polar or nonpolar and why?
Ethanol is a polar solvent. Its dipole moment is 1.69D. Now, a bond is generally considered polar if the electro negativity difference between the two bonded atoms is greater than or equal to 0.5. So, C-H bonds are not considered as polar.Hence the ethyl group is almost non-polar. But, it is the O-H bond that causes polarity to the ethanol molecule. In O-H bond, O atom is in sp3 hybridized state and the geometry of orbitals around O atom is tetrahedral, with two vertices occupied by lone pairs of electrons. Now, O atom is bonded to ethyl group on one side and H atom on the other, with a bent shape. O-H and O-C bonds are both polar, oriented angularly with respect to each other. That is why ethanol molecule is polar.
Why are oil supplies limited?
1. Oil supplies are limited because there is only a fixed amount of it in the world (much like all other resources, even including air and water). 2. It took millions of years of heat and pressure to make the oil we have today, it would take millions more to produce more oil. By the time there are significant new supplies, we won't care, because the human race will have either left the earth or died out. 3. The most popular prediction of our supply of oil is called the peak oil theory, and it says that we have already hit our high point in oil production, and in the future, it will decline. This is not to say that we will run out of oil in the future, just that extracting it will become more expensive and dangerous. We are currently searching for oil in very deep waters in several of the world's oceans,and exploring the feasibility of separating out the oil from Canada's tar sands. So we won't just run out, but the price will rise until other alternatives become economically competitive. 4. Predictions of future oil supplies depend on many different factors,and there are many places on the globe where we have not explored yet. Technology is another significant factor affecting oil supplies. If we can learn how to exploit the tar sands, deep oil deposits in the ocean, and perhaps explore the polar region, we could extend our oil supply significantly. Differing assumptions about the amount of oil we could get to and the technology we develop to exploit it can make estimates vary widely. I hope this helps.
What is the difference between polar and non polar molecules?
In a non-polar molecule, the cloud of electrons around the atoms in the molecule are relatively evenly distributed. You see this when the atoms in the molecule have very similar affinity for electrons. Affinity means the tendency of the atom to hold an electron to itself.Polar molecules, the electron cloud of the molecule is unevenly distributed so that the electrons are much more likely to be at one end of the molecule than the other. As a result, one end of the molecule is relatively more negative, and the opposite end relatively more positive. The electric field around the molecule looks like that of a small dipole.Overall, the polar molecule is electrically neutral. But closer in, the dipole becomes important, because the polar molecule will interact with other neighboring polar molecules. The positive end of one will attract the negative end of the other, and vice versa. This will cause inter-molecular forces of attraction which have an impact on chemical behavior and other phenomena.Water is a good example of a polar molecule.The oxygen atom attracts electrons much more powerfully than the hydrogens. This is one reason polar and ionic compounds dissolve better in water than non-polar. This has relevance to biology too: when you talk about hydrophilic and hydrophobic, this generally relates to whether the substance is polar or non-polar. And the phenomenon of hydrophobic and hydrophilic molecules and ends of molecules plays a role in such things as the structure of cell walls.Water's polarity also affects the interaction with an electric field. Electric dipoles rotate to align with an electric field. This is a main reason electrical activity is associated with large rainclouds. And microwave ovens depend on this principle, with a particularly tuned alternating electric field making water dipoles rotate.Small regions of a larger molecule can also be polar. An example is a Hydrogen bond, where hydrogen (with a weak affinity for electrons) is bonded to something like oxygen or nitrogen with a high affinity. Hydrogens on one such molecule can be attracted to the negative region of a neighboring molecule. Hydrogen bonding plays a role in such things as the high surface tension and boiling point of water, as well as some important elements of structure in proteins and DNA. It also plays a role in the viscosity of solutions such as concentrated sugar solutions like molasses or maple syrup.