Today we recognize two types of cells in science, prokaryotes and eukaryotes. A prokaryotic cell is one that lacks all membrane-enclosed organelles, including a nucleus, whereas a eukaryotic cell has a a multitude of different organelles, all with different functions (Urry et al. 2014). Prokaryotes are single cellular organisms that consist of a one prokaryotic cell, and include bacteria and archaea. There are many different types of these specific cells though, with many different formations. Three examples of this are coccus, spirillum, and bacillus. These are the three most common forms of prokaryotes that we know of today (Urry et al. 2014). Eukaryotes actually have an interesting history with their prokaryotic predecessors. The theory …show more content…
Osmosis occurs when molecules of water move between a semi-permeable membrane to diffuse a solvent equally between the both sides of the membrane. This is a form of passive transport, where the particles move without using any form of energy form the cell (Urry et al. 2014). The most important fact to note is the idea that substances with diffuse from a higher concentration of a solvent to a lover concentration, down their concentration gradient (Urry et al. 2014). So, if we had a solution with 30% concentration of sucrose on one side of the membrane, and a 10% concentration of sucrose on the other side, we would notice the water diffuse until both sides had an equal amount of 20% sucrose. The result of this would be that the side which originally had the 30% sucrose solution would be at a much higher water level than when it started, because it had to take in more water from the other side of the membrane to get the new concentration of 20% sucrose (Urry et al. 2014). Due to this background knowledge in osmosis, we hypothesized that concentration gradient would have a greater affect on osmosis than temperature, because a larger amount of sucrose would want to diffuse out to make both solutions …show more content…
These solutions are always relative to the cell we are looking at. A hypertonic solution, is one that more solutes, and as a result causes the cell to lose water, and shrink in size. A hypotonic solution, is one that will make a cell swell as water freely flows into it, sometimes causing the cell to burst. An isotonic solution is the median between the two, it is a solution in which a cell is not losing or gaining water, and so the cell stays the same as it was before it was in the solution (Urry et al. 2014). Most animal cells prefer to be in an isotonic solution so they don’t have to swell and shrink, but most plant cell excel in hypotonic solutions that allow them to suck up as much water as possible (Urry et al. 2014). Because we had this background knowledge we hypothesized that we hypothesized in the portion on osmosis in potato tissue, that the higher concentration of NaCl, that the potato slices would become more
During the lab, I also learned about hypertonic solutions and hypotonic solutions. The hypertonic solution concentration of the cell is less than the outside of the cell. (Trent, 1) Hypotonic solutions have a higher concentration in it than the area surrounding it. Trent, I learned about hypertonic solutions when we placed the egg in corn syrup, which caused the egg to deform and become squished. I learned about hypotonic solutions when we placed the egg in water, which caused the egg to swell.
There are many different cells that do many different things. But all of these cells fall into two categories: prokaryotic and eukaryotic cells. Eukaryotic cells contain a nucleus and are larger in size than prokaryotic cells. Prokaryotic cells do not contain a nucleus, are smaller and simpler than eukaryotic cells. Two of their similarities are they both have DNA as their genetic material and are covered by a cell membrane.
I also predict that solution concentration 0.3 will be isotonic because of the pressure potential. As the water moves into the cell it pushes up against the cell wall this is called the pressure potential and it increases the water potential until an equilibrium is reached, and because the cell is so inelastic it takes very little water to achieve this. That's why I believe in-between 0.3 and 0.4 will be isotonic as it is very close to pure water. Background Information Osmosis - The net movement of water molecules from a region of high water potential to a low water potential, through a selectively
The Effect of Solute Concentration on the Rate of Osmosis Aim: To test and observe how the concentration gradient between a potato and water & sugar solution will affect the rate of osmosis. Introduction: Osmosis is defined as, diffusion, or net movement, of free water molecules from high to low concentration through a semi-permeable membrane. When a substance, such as sugar (which we will be using in the experiment we are about to analyse), dissolves in water, it attracts free water molecules to itself, and in doing so, stops them from moving freely. The effect of this, is that the concentration of (free) water molecules in that environment goes down. There are less free water molecules, and therefore less water molecules to pass across a semi-permeable membrane, through which sugar molecules and other molecules attached to them are too big to diffuse across with ease.
There will be a net movement in these types of solution. The molecules will move from the hypotonic solution into the hypertonic solution. The third way a substance can cross the cell membrane is through facilitated diffusion.
Osmosis is a type of diffusion which is only applied on water and is a passive process which does not require an input of energy from the cell; this is because materials are moving with the concentration gradient. Osmosis is a process that occurs at a cellular level, which entails the spontaneous net movement of water through a selectively permeable membrane, from a region of high to low water concentration, in order to equalise the level of water in each region. This form of diffusion takes place when the molecules in a high concentration are too large to move through the membrane. The term semi-permeable or selectively permeable means that some substances can easily pass through the cell membrane, whereas others cannot. The significance of osmosis to cells is great, since it is the osmotic pressure that maintains the shape of an animal cell and provides support in the plant cells. Many factors affect the rate of osmosis including size of particles and temperature however in this particular experiment the factor investigated is the concentration of sodium chloride. Tubes of potatoes will be used to demonstrate the fact...
In osmosis, water can travel in three different ways. If the molecules outside the cell are lower than the concentration in the cytosol, the solution is said to be hypotonic to the cytosol, in this process, water diffuses into the cell until equilibrium is established. If the molecules outside the cell are higher than the concentration in the cytosol, the solution is said to be hypertonic to the cytosol, in this process, water diffuses out of the cell until equilibrium exists. If the molecules outside and inside the cell are equal, the solution is said to be isotonic to the cytosol, in this process, water diffuses into and out of the cell at equal rates, causing no net movement of water. In osmosis the cell is selectively permeable, meaning that it only allows certain substances to be transferred into and out of the cell.
If a plant cell is places in a hypotonic solution the cell has a lower water concentration to that of the solution. Water will move into the cell by osmosis from a high water concentration outside the cell to a lower water concentration inside the cell through a selectively permeable membrane. The cell becomes turbid
Investigation of the Concentration and the Effect of Sucrose on Osmosis in Apple and Potato Tissues
Cells are constantly dividing, which means that DNA is constantly replicating itself. Every cell in the body has the same copy of DNA. Replication requires three things: something to copy, or in other words a template, something to copy it, or nucleotides which provide a complimentary strand to the template, and the tools that are essential to actually build it, which in prokaryotes’ case are the three types of DNA
Scaling is where salts such as: calcium carbonate, calcium sulphate and magnesium hydroxide precipitate out of the water due to super-saturation and deposit onto the partially-permeable membrane and block the pores. This results in a reduced water flow through the membrane and a larger pressure gradient which can cause increased strain on the partially-permeable membrane. The main cause of the build-up of scale is the saturation point of the salt, when this point is reached no more salt can be dissolved in the water and the salt begins to precipitate out causing scale to form. Magnesium and calcium possess a property known as inverse-solubility, as the temperature is increased the solubility decreases. This means that more of the substance precipitates out of the solution at higher temperatures causing increased scaling. It is important not to use high temperatures in the plant as this will cause the level of scaling to increase. Calcium carbonate is the largest cause of scale formation and is formed from bicarbonate and calcium ions in the following
Prescott, Harley & Klein (1990) describe bacteria as prokaryotic cells (cells that lack a true membrane enclosed nucleus). Bacteria are both small and simple in structure; they usually are between o.5 and 5cmm yet they have many characteristic shapes and sizes. Some bacteria are circular or oval shaped, they are known as cocci bacteria. Other bacteria are rod-shaped, they are known as bacilli bacteria, and some bacteria are spiral and coil-shaped and it is know as spirilla bacteria.
Osmosis is a biological process. If equilibrium is ever achieved, then water molecules will move. back and forth between the substances. If a surrounding sucrose solution has a lower water potential than the plant tissue in the solution, then, through osmosis water will move from the tissue into the. the surrounding solution, the tissue will lose mass and length as a result.
Prokaryotic cell: have no membrane covered organelles, they also have circular DNA and bacteria, Eukaryotic cell: have membrane covered organelles, they also have linear DNA and all other cells. Also the cell cycle is short in prokaryotic cells, roughly taking about 20-26 minutes to complete. And in eukaryotic cells, the cell cycle is long, it usually takes about 12-24 hours to complete. Below is a table of some of the differences between the cells:
All cells are the product of multiple rounds of cell growth and division, new cells are formed from existing cells, as has been the processes since the beginning of life on Earth. The reproduction of new cells is a very organized sequence of events called the cell cycle. This cycle is the essential mechanism by which all living cells reproduce whether unicellalur or mutlicelluar the basic mechanism is universal. However, variations in the details do occur from organism to organism and the cycle can start at different times in the organism’s life. The Eukaryotic cell cycle usually consist of four phases.