Plasma Membrane Worksheet

1.Discuss the structure of the plasma membrane and explain the process of active and passive transport through the membrane.

The purpose of these experiments is to examine the driving force behind the movement of substances across a selective or semiperpeable plasma membrane. Experiment simulations examine substances that move passively through a semipermeable membrane, and those that require active transport. Those that move passively through the membrane will do so in these simulations by facilitated diffusion and filtration. The plasma membrane’s structure is composed in such a way that it can discriminate as to which substances can pass into the cell. This enables nutrients to enter the cell, while keeping unwanted substances out. Active

3. Explain your prediction for the effect Na+ Cl- might have on glucose transport. In other words, explain why you picked the choice that you did. How well did the results compare with your prediction?

diffusion is one of the passive transport processes. it is used in oxygen entering a cell and carbon dioxide leaving a cell. diffusion is the movement of particles such as atoms or molecules from a high concentration place in an area of a low concentration. this shows that they diffuse down the concentration gradient. the concentration gradient is a gradual change in the concentration of solutes in a solution as a function of distance through a solution. in biology a gradient results from an unequal distribution of particles across the cell membrane. When this happens solutes move along the concentration gradient until the concentration of the

* Cells allow things to go in and out of the organism (allows diffusion to happen so good things go in and bad things go out)

“All the cells take in and use nutrients and other substances from their surroundings. Cells of the intestine and the kidney are specialized to carry out absorption. Cells of the kidney tubules reabsorb fluids and synthesize proteins. Intestinal epithelial cells reabsorb fluids and synthesize protein enzymes” (McCance & Huether, pg. 2).

12. How is glucose transported from the blood to the cell? (P. 26 bottom right, p 29 mid left)

1. What two parameters are responsible for creating the movement (filtration and reabsorption) of fluid across the capillary wall?

Describe the conformation of the phospholipid bilayer of the plasma membrane. What abundant fluid leads to his conformation? Because the phospholipids heads are

The plasma membrane, as well as lipids, includes several proteins; the proteins that are within the membrane are found buried or embedded into the lipid bilayer. These proteins include enzymes, receptors and antigens. There are four methods of transportation both in and out of a cell; diffusion, facilitated diffusion, osmosis, and active transport. Fick's law is used to measure the rate of diffusion: [IMAGE] Diffusion is the movement of atoms, molecules or ions from a region of high concentration to a region of low concentration (down the concentration gradient²). The energy for this to occur comes directly from the particle itself; this is defined as passive (not requiring energy).

Exercise 1: Cell Transport Mechanisms and Permeability: Activity 3: Simulating Osmotic Pressure Lab Report Pre-lab Quiz Results You scored 100% by answering 4 out of 4 questions correctly. 1. Which of the following is true of osmosis? You correctly answered: c. It is a type of diffusion. 2. Which of the following occurs when a hypertonic solution is added to cells? You correctly answered: d. The cells shrink. 3. The variable that affects osmotic pressure is You correctly answered: a. the concentration of nondiffusing solutes. 4. The net movement of water would be into the cell in a You correctly answered: b. hypotonic solution.

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

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

Glucose transport proteins can only transport glucose proteins in and amino acids can only carry amino acids in.

The plasma membrane is close to animal cells where the exchange of substances inside and outside of cells revenue a place . Some of the substances have to move between the extracellular fluid outside cells to inside of the cell, and some elements necessity to interchange from inside to the extracellular fluid.