Nu 545 Exam 1 Study Guids Essay

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

There are many parts of a cell, they all have specific duties, and are all

When glucose carriers in the membrane were set to 500, the glucose transport rate for 2.00 mM of glucose was .0008 mM/min. Equilibrium was reached at 43 minutes. At 700 glucose carriers the rate was .0010 mM , and equilibrium was reached at 33 minutes. When the glucose carriers was set at 900 the rate was .012 mM/min, and equilibrium was reached at 27 minutes. After changing the glucose concentration to 8.0 mM, the glucose transport rate with 500 carrier proteins was .0023 mM/min, and equilibrium was reached at 58 minutes. With the simulation set at 700 carrier proteins the rate was .0031mM/min, and equilibrium was reached at 43 minutes. When the simulation was done with 900 carrier proteins the glucose transport rate was .0038, and equilibrium was reached at 35 minutes.

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?

“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).

1. Understand the importance of diffusion to cellular metabolism and the how it constraints the evolution of cell/body size and shape

P4- Explain the Physiology of Two Named Body Systems in Relation to Energy Metabolism in the Body

Breaking down an organism leads scientists to identify cells. A group of cells create tissues, tissues combined are organs, and organs and their functions make up systems. Basically, cells make up living organisms. There are 2 kinds of cells: Prokaryotic and Eukaryotic. Within a prokaryotic, it doesn’t contain a DNA bounded nucleus; however, a eukaryotic cell does. Though the prokaryotic cell differs from a eukaryotic cell, they share a cell membrane. The cell membrane is composed of a phospholipid bilayer and proteins, which makes it selectively permeable. It is located outside of the cytoplasm and controls the movement of substances in and out of the cell. Its basic function is to protect the cell from its surroundings by selecting what can enter and exit the cell.

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

Glucose is the body’s key source of energy. In order to make ATP glucose is processed from a metabolic pathway called glycolysis. The first step of glycolysis is phosphorylation of glucose. This prevents the diffusion of glucose out of the cell. Due to the charged phosphate group glucose does not easily cross the cell membrane which is where the process of facilitated diffusion comes in. Facilitated diffusion uses a channel protein to allow a component to move down it’s concentration gradient. It is also good to note that since insulin signals are synthesized at the membrane bound polyribosomes and are therefore hydrophilic, they require a TMP for transport across the lipid bilayer. These processes are possible because of ribosomes-studded

Fig. 3- Glucose in the tubular epithelial is transported down a concentration graident via GLUT1, across the basolateral membrane into portal circulation. Glucose maximum absorption is 375 mg/min. Once that gradient has been crossed glucose is excreted in urine due to the inabilty of SGLT2 transporters ability to reabsorb [6]

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

SGLT1, involved in the active transport, activated on the side of intestinal lumen. These transport protein requires ATP to bind Na+ on one side and glucose/galactose on the other side. Na+ATPase pump both sodium and glucose molecules through and then out of the cell membrane and they are lastly transported to the bloodstream by the assistance of GLUT2. After meals, blood glucose level raises up in the intestinal lumen. Glucose needs to be transported into the enterocyte through facilitated transport with help of GLUT2. GLUT2 is activated

Facilitated diffusion is the movement of molecules from higher to lower concentrations. Polar molecules and ions embedded in the lipid bilayer diffuse passively with the help of transport proteins that span the membrane. The layer is selectively permeable, meaning they transport some substances but not others. Within active transport there are two types of transport proteins, channel and carrier. Channel proteins provide a hydrophilic passage for a specific molecule or ion to the cross the membrane. The passageways for these proteins allow water molecules or small ions to flow very quickly from one side of the membrane to the other. Despite the small size of water molecules, movement through the phospholipid bilayer is still slower because of the polarity of the water. Another type of channel proteins is the aquaporins. Aquaporins facilitate the amounts of diffusion that occur in plant and animal cells. Another example of channel proteins are ion channels, many of which are gated channels, which open or close in response to stimuli. The stimuli can be electrical or chemical. One example of this is the nerve cell, its stimuli is the electric message sent from the brain and responds depending on the stimuli sent. Carrier proteins undergo a subtle change in the shape that somehow translocates the solute-binding site across the membrane. These changes in shape may be triggered by binding and release of the transported

The movement of molecules have two forms of transport through the plasma membrane: active transport and passive transport. Active processes require energy, such as ATP, in order for the molecules to be transported. In active transport, the cell administers ATP.i Within passive processes no energy is required and changes n pressure and concentration are the driving forces. Processes such as simple diffusion, facilitated diffusion, osmosis, and filtration are characterized as passive transport, while solute pumps are a form of active transport. Each of these form of transports occur in the cells of all living organisms and are essential to life.