Active Transport Lab Report

Resting potentials require ions as they play a vital role in the process. In the surface membrane of a cell there are protein carriers. These actively pump Na+ ions out of the cytoplasm to the outside of the cell. At the

Increasing the extracellular potassium reduces the concentration gradient, and less potassium diffuses out of the neuron and into the cell.

A type of transporter that binds two or more ions Or molecules and transports them in the same Direction across a membrane. 25.The transport of Ca2+ from the cytosol (low Ca2+  concentration) into the endoplasmic reticulum (high Ca2+ concentration) describes what kind of transport? Active transport 26.Acetylcholine binds this membrane protein, which subsequently opens to allow sodium to enter the cell. Acetylcholine exerts its effect on what type of transport protein? Ligand-gated channel 27.Sodium concentrations are higher outside and glucose concentrations are higher inside the cell.

Both electrical and chemical forces combine to determine the resting membrane potential of the cell. Although the resting membrane potential of most cells is normally negative, the selective permeability of the membrane allows certain ions in and out, causing the neuronal membrane voltage to become depolarized (more positive), or hyperpolarized (more negative). Key ions involved in muscle membrane potential are sodium, potassium, and chloride, which move via passive or active diffusion through ion channels and transporter pumps (Baierlein et al. 2011). The Nernst equation predicts the membrane voltage based on the assumption that the membrane is only permeable to one type of ion. In this investigation, we are seeking to understand the basis for how different ions interact to produce the membrane potential of DEM, DEL1, and DEL2 crayfish muscle

___The concentration of extracellular K+ ions would be high and this would prevent more K+ ions from diffusing out of the cell.

-If the potassium transport pump was blocked the leakage channels would still be open allowing Na+ to

In this lab, neutral red was used as a pH indicator. The color changes from yellow to red in a basic solution to an acidic solution. The neutral red dye was applied to Saccharomyces Cerevisiae. When the S. Cerevisiae cells come in contact with the neutral red dye, the dye gets to the cell by crossing the cell membrane. The cell membrane is the outer surface of the cell that functions as a barrier. The outside of the cell membrane is made of lipid and membrane proteins (Hardin, 2012). It is selectively permeable, which means only select ions and molecules can pass through it by transport. Membrane transport can be actively or passively moving a substance from side of the membrane to another (Hardin, 2012). Passive transport does not require energy to move molecules across the cell membrane. Diffusion is a form of passive transport that moves molecules across the membrane from an area of higher concentration to an area of lower concentration. Osmosis, diffusion, and facilitated diffusion are all examples of passive transport. Active transport requires energy to move molecules across the membrane from areas of lower concentration to higher concentration. It requires energy because it pushes sodium ions (Na+) and potassium ions (K+) (Hardin, 2012). When the dye entered the cell, it also showed its location. Sodium azide (Na+N3-) is a metabolic inhibitor that blocks the flow of electrons along

A nerve cell has a negative charge at a resting state due to negatively charged proteins within the cell.[3] Although the inside of the cell contains positively charged potassium ions as well, overall the charge is still negative. Along with potassium on the inside of the cell, positively charged sodium ions are located around the exterior of the cell.[3] When an action potential occurs, the cell becomes even more negatively charged. In turn, this causes sodium transport molecules in the membrane of the cell to open.[3] Sodium will then enter the cell during active transport. The positively charged sodium will cancel out the negatively charged active potential which will depolarize the cell. This allows neurotransmitters to transfer from cell to cell.[3] These neurotransmitters are what allows the body to feel pain. Local anesthetics work by diffusing through nerve fibers. Once they’ve reached the cells, they block the sodium transport molecules in the cell.[2] Therefore neurotransmitters cannot transfer information from cell to cell and the feeling of

The establishment of electrochemical gradient is one of the driving forces for ion movement across the cell membrane. Cells are usually negative and surrounded by positively charged extracellular fluids. All transport processes across cells impact the chemical gradients. There are two primary transport processes that affect electrical gradients, electroneutral carriers and electrogenic carries. Electroneutral carries transport uncharged molecules or exchange an equal number of particles with the same charge across the membrane, ultimately not changing the overall elecrtochemical gradient. Electrogenic carriers result

Increasing extracellular K+ reduces the net diffusion of K+ out of the neuron through the K+ leak channels because the membrane is permeable to K+ ions. Therefore, the K+ ions will diffuse down its concentration gradient from a region of higher concentration to a region of lower concentration.

Hence, this would allow for an influx of sodium into the cell down its electrochemical gradient. It would also allow for the flow of potassium outward, as it has a 140mM concentration inside the cell and wants to shift down its concentration gradient to 5.4mM. Therefore, this great driving force for the influx of sodium and efflux of potassium helps to explain the findings at this point. As Table 1 shows, the findings within this figure are statistically supported. The fact that there is not significant difference between the findings of this experiment and the calculated Nernst at the 10, 20 and 40mM of potassium is an indicator that sodium is the largest determinant of the resting membrane potential. However, some findings defy the expectations, as the last two concentrations elicit a resting membrane potential significantly more negative than expected. This can be explained by the fact that at this point, each muscle at their respective muscle groups has been protruded many

Cells are always in motion, energy of motion known as kinetic energy. This kinetic energy causes the membranes in motion to bump into each other, causing the membranes to move in another direction – a direction from a higher concentration of the solution to a lower one. Membranes moving around leads to diffusion and osmosis. Diffusion is the random movement of molecules from an area of higher concentration to an area of lower concentration, until they are equally distributed (Mader & Windelspecht, 2012, p. 50). Cells have a plasma membrane that separates the internal cell from the exterior environment. The plasma membrane is selectively permeable which allows certain solvents to pass through

The Sodium-Potassium Pump is a structure known as a cell-membrane pump that uses energy to transport Sodium and Potassium ions in and out of the cell. There are other varieties of cell membrane pump, however the sodium-potassium pump plays a vital role in maintaining a cell's homeostasis.

To study the effects of hypotonic, hypertonic and isotonic solutions on plant and animal cells.

Active transport is a process that requires ATP in order for molecules to move. There are several reasons why active transport is required as oppose to passive transport: substances may be too large to pass through the membrane, substances may move against the concentration gradient as oppose to with it, or some substances may not be lipid soluble. v Amino acids and some sugars are transported into cells by solute pumps. An example of a solute pump is a sodium-potassium pump. Within a sodium-potassium pump, both K+ and Na+ are pushed into opposite regions across the cell membrane. Other processes that require ATP are pinocytosis and phagocytosis. Both pinocytosis and phagocytosis occurs when the cell membrane descends beneath the material in order to create a small vesicle, then pinches off into the cell. vi Phagocytosis is the process of cell eating, and phagocytic cells work