Osmolarity Lab Report

This experiment seeks to analyze how the resting membrane potential of Orconectes rusticus muscle cells changes in response to increasing [K+]o solution concentrations. By recording the intracellular voltage of the DEM, DEL1, and DEL2 crayfish muscle cells at six concentrations of [K+]o solution, we determined whether the observed resting membrane potentials (Vrest) were significantly different from the predicted Nernst equilibrium potential values. We hypothesized that the Vrest of the crayfish muscles at each concentration would not significantly differ from the Nernst potential, which solely considers the permeability of potassium ions to the cell membrane. However, our findings suggested differently, and results indicated that the Nernst equation did not accurately predict the obtained values of the resting membrane potential. The differences in muscle cell Vrest reveal instead that the membrane is differentially permeable to other ions.

The lobsters which were put in tanks of varying salinity adjusted their hemolymph osmolarity to that of the external environment, making Homarus americanus an osmoconformer. The tank which had the lowest salinity

osmosis- a process by which molecules of a solvent tend to pass through a semipermeable membrane from a less concentrated solution into a more concentrated one, thus equalizing the concentrations on each side of the membrane

The concept of osmotic pressure must be understood when studying osmosis. The movement of water from a hypotonic solution through the membrane into a hypertonic solution can be prevented by applying force or pressure on the hypertonic side. The force that must be applied to prevent osmotic movement of water from hypotonic to hypertonic, measured in atmospheres, is referred to as osmotic pressure. Solutions with greater concentrations of OAS have greater osmotic pressures because greater force is required to prevent water movement into them. Distilled water has an osmotic pressure of zero.

Jonathan Edwards effectively uses causal, inductive, and analogical logos to persuade his congregation through reasoning and logic, in “Sinners in the Hands of an Angry God” in which he wants them to realize that their God is, in fact, angry with them. His use of logos is apparent early when Edwards tells the “reason why they do not go down to hell at each moment,” followed by “because” which is causal logos and appeals to the logical side and sets up his concern and his argument. (lines 10-11; italics mine) Continuing the use of “because” and causal reasoning as well as refuting his congregation's argument that God is merciful, Edwards states “it is not because God is unmindful of their wickedness, … he does not let loose his hand and cut

A very carefully regulated process is solute concentration. If there is a sudden increase in water which enters the extracellular fluid, sodium ions will then contribute less to the extracellular solute concentration as the ratio between water and solute has now changed. Osmolality is the amount of solute in a kilogram, hence the osmolality in the extracellular space has also decreased.

Osmosis is described in one of three ways when comparing more than one solution. The cell’s external and internal environment helps determine tonicity, which is defined as how the cell reacts to its environment. When the cell’s environment is equal in osmolarity to itself and there is no change, it is considered an isotonic solution. When the environment has a higher osmolarity, shrinkage occurs and it is considered a hypertonic solution. When the environment has a lower osmolarity, swellings occurs and it is considered hypotonic.

Osmosis can be defined as the force that drives the movement of water due to differences in solute concentration. The process involves the random movement of molecular water molecules through a semi-permeable membrane from regions of higher concentration to regions of lower concentration until both regions equal out (Ledbetter 2013, Ness 2013). Polar substances such as glucose and salts cannot travel through the cell membrane, which

The concentration of solutes in the bodily fluids of most marine invertebrates is roughly isosmotic to their environment (Raven, 2008). Because there is no osmotic gradient there is no tendency for the net diffusion of water away from the animal’s cells to occur. When a change in salinity occurs some organisms have the ability to maintain a constant internal homeostasis despite these external changes and are known as osmoregulators (Oxford, 2008). Other animals lack this ability and as such are called osmoconformers; their internal osmolarity matches that of their

In osmosis, the flow of the water from or to a cell depends on whether the cell is immersed in a solution that is isotonic, hypotonic, or hypertonic to the solution. If the cell is isotonic to a solution, this means that the solute concentration of a cell and its environment is the same and therefore there will be no movement of water. If the solute concentration is lower than that of the cell, then water will flow into the cell, causing it to expand. If the solute concentration is lower than that of the cell then water will flow out of the cell, causing it to shrink.

Within every cell, a movement of a solvent occurs through a semipermeable membrane to equalize the concentration of solute on both sides of the membrane. The diffusion of water across the cell’s membrane down to its concentration gradient is called osmosis. In this case, the concentration gradient is the difference of density between one side of the cell membrane to the other. Since the cell’s membrane is permeable, particles can flow freely in and out of the cell, but the net flow will be strong in the direction of lower concentration until the system has reached a stage of equilibrium, the point at which both sides of the membrane are equal. In the

Osmosis is the passive movement of water from an area of low solute concentration to an area of high solute concentration, normally across a membrane which prevents the movement of solvent. This is a process by which materials may move into, out of, or within cells. Osmosis doesn’t depend on energy provided by living organisms but is affected by the properties of the cell membrane. The rate of osmosis is dependent on such factors as temperature, pressure, molecular properties such as size and mass, and the concentration gradient. In osmosis, the relationship between a solute’s concentration outside of cell and inside of a cell is described in terms of the tonicity of the solution outside of the cell. A cell is in a hypotonic solution when the solute is more concentrated inside the cell and therefore water moves into the cell. In this solution the cell swells as water enters, this may continue until it ruptures or hemolyzes. In the reverse condition, the cell is in a hypertonic solution

The answer is B, in the cells of a tide pool animal such as an anemone. This is because tidepool animals are constantly surrounded by water and use osmoregulation to regulate the movement of water in and out of the cell, getting rid of extra water that enters the cells once the inside and outside of the cells are isotonic. The answer could not be A because plants do not osmoregulate due to their desire to constantly be hypotonic and have things coming into the system. It can not be C because red blood cells must reside in an isotonic solution or it will burst and therefore no osmoregulation is needed. Lastly, the answer can not be D because lymphocytes do not osmoregulate

This experiment was used to examine the hypothesis that: Osmosis is dependent on the concentrations of the substances involved.

Osmosis is when water passes through a cell membrane, it is also form of a diffusion, which is a form of passive transport. Osmosis will continue to until an equilibrium is reached which is when the solutions are isotonic. This means that the solution has the same amount of solute on both sides. If the solution is hypertonic, it has more solute in the solution. In this situation water will move towards it. if the solution is hypotonic, it has less solute in the solution. Whereas in this situation, water will move out of the solution.