Cell Membrane Lab Report

Humans transport things around the world just like the cell membrane. The cell membrane uses active transport which uses energy to move thing around. It also uses passive transport that doesn’t require energy at all to move molecules. In order for things to move around in the cell membrane, it needs the cell transport. The cell membrane won’t be a membrane without cell transport.
Cell membranes are selectively permeable which can let things in and kick some out. The cell membrane is liquidly and is made out of different things like a mosaic. That’s how the cell membrane got its name fluid mosaic model. The fluid mosaic model of the cell membrane has a different mixture of phospholipids, cholesterol, and proteins. The carbohydrates are attached

to lipids and to a protein that are sticking out the cell membrane. Each phospholipid has a head that is attracted to water which is called a hydrophilic and a tail that hates water which is called hydrophobic. Cholesterol moves itself in between the phospholipids. According to Khan Academy, the cholesterol increases the distance between the phospholipids which increases the fluidity. In high temperature, the cholesterol makes the fluidity will decrease but in low temperature the fluidity increases. Peripheral proteins have weaker connections to the membrane. It’s usually found outside of the membrane. It can remove its self. The peripheral is sometimes there for the cell process. Integral proteins are connected to the cell membrane. Integral protein has glycoprotein. Integral protein is usually found inside the cell membrane.
One type of passive transport is diffusion.

Diffusion is when any molecule moves from high to low concentration. Molecules will spread until they have equilibrium. Diffusion equilibrium is reached when the concentration gradient reaches zero. In the lab that we did in class was diffusion. We used iodine and starch. We put starch in the plastic tube and tied it making sure there was no starch on the edges. Then we put iodine in the water and put the starch in the iodine. We kept it for a while. The iodine went in the starch making the water clear and the starch to turn from white to dark brown. This shows diffusion because it shows how the iodine went from high concentration to low concentration. A real life example of diffusion is when you spray perfume in one corner of a room, the molecules of the spray will move around the room. That’s

diffusion.
Osmosis is when the water moves from high concentration to low concentration. A real life example is when you soak dehydrated fruit and vegetables until they become big. Another example of osmosis is when we did the egg experiment. What we did in day 1 is that we measured the height and the weight of the egg. The weight was 52 and the vertical height is 16cm while the height horizontal was 13.3cm, after that we put the egg in an empty cup then poured vinegar in the cup. We left it for 24 hours then we checked it. The shell of the egg was breaking apart. The height and weight also changed, instead of weighing 52 it went down to 37. The vertical of the egg became 16.5cm and the horizontal is 14.6cm.We also did an experiment in water. We did the same when we put it in the vinegar. We weighted the egg which was 54. The height vertically was 15.9 and horizontally was 14cm. we left it in the water for 96 hours. When we checked it the egg expanded a little. The weight became 36 the height was 16.3 cm vertical and 14.2cm horizontal. It has to do with osmosis because it shows you the diffusion of water. It shows you how the water went from outside to inside the egg to make it equal. When we put the egg in the vinegar, the vinegar was hypertonic. When we put the egg back in the water, the water was hypotonic.
Facilitated diffusion is when molecules move through a channel protein in the cell membrane. According to the cell article, facilitated diffusion can occur if your blood pressure is higher than you muscle cell. It occurs through the channel proteins. Carrier proteins can move molecules across the membrane. The carrier protein helps facilitated diffusion in integral protein. Aquaporin is an example of a tunnel. Aquaporin transfers water in the membrane.
Active transport requires energy to move. Molecules use protein pump to move. For example, in the cell article, it says, “Those pumps need ATP to make these molecules through the cell membrane into a high concentration”. Sodium-potassium pump is when you move sodium and potassium molecules across the membrane. According to the khan academy, it states, “The sodium-potassium pump transports sodium out of and potassium into the cell in a repeating cycle of conformational (shape) changes”. An example of sodium-potassium is your nerve cells. In the cell article, it says, “your nerve cells will only send signals if there is a high concentration of sodium ions outside the cell and a high concentration of potassium ions inside the cell.” Which means your nerve cell will only send signals if both sodium and potassium have a high concentration. Also Active transport is a transport against the concentration gradient. The moves from low concentration to high concentration.
Bulk transport mechanisms are when big molecules are being moved in the membrane.

Endocytosis is when a cell wraps the cell membrane around a particle in order to pull it into a cell. A real life example is when you eat a cheeseburger; you need the energy to grab it, then eat it, and then digest the cheeseburger. Phagocytosis is when the cell uses endocytosis to pull the solid particles. A real life example is when an animal hunts and consumes its prey. Pinocytosis is when the cell uses endocytosis to pull the liquid particles.
Cell transport is when materials move across the cell membrane. Without cell transport things won’t be able to move around and the cell could not move material into or out of the cell which means the cell can’t get what it needs. The cell membrane is related to all of these types of cell transport because it transports the molecules either through the active transport or passive transport. Cells need to maintain stable internal conditions because it is the one that needs to get rid of carbon dioxide and other things. If it’s not stable our human body wont function

well.