The Membrane And The Cell Membrane

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

The fluid surrounding the cells called tissue fluid are bother watery environment. Also, it’s the outside of any large cell. The function is to protect the cells from the surroundings. It also allows things to enter in and out of the cell this will maintain the support of cell and shape. Nucleus

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

Essentially, the nucleus is vital for the cell’s survival. The nucleus controls and gives instructions to all organelles and inhabitants of the cell(Doc. 2). It is a dense, ball shaped configuration that contains the DNA of the cell.

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

All organisms need to exchange particles such as food, waste, gas and heat with their surroundings. there are two different types of ways in which substances can enter or/and leave a cell. these ways are called Passive and Active. with in these there are different processes for example, in passive process there are diffusion, facilitated diffusion and osmosis and in the active process there is molecule and particle. in this assignment I am going to discuss all of these processes starting with diffusion.

1. Why do you think it is important to have a membrane surrounding each of our trillions of cells? Expect varying answers, but the idea is have the students understand the plasma membrane separates the cells from their environment and each other while also regulating the material within each cell. 2. What are two distinctive physical features of phospholipids? Heads are polar (water soluble, hydrophilic) and tails are nonpolar (water hydrophobic).

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).

is something that lets some things in and some things out of the cell. It is an outer cover for the cell. If the cell membrane was non existences the cell would spill all over the place. Its function is to protect the integrity of the interior of the cell by allowing certain substances into the cell, while keeping other substances out. It is composed of a thin, double-layered sheet of lipids, around the Cell and is a protective membrane layer around every Cell.

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.

The cell membrane consists of eight distinctive parts that each have their own unique structure and function. The phospholipid bilayer is an integral part of the cell membrane because it is the external layer of the cell membrane and composes the barriers that isolate the internal cell components and organelles from the extracellular environment. It is composed of a series of phospholipids that have a hydrophobic region and a hydrophilic region. These regions are composed of the hydrophilic heads and the hydrophobic tails of the phospholipids, this organization of the polar heads and nonpolar tails allows the heads of the cell to form hydrogen bonds with water molecules while the tails are able to avoid water. The phospholipid bilayer also has many important functions within the cell, it gives the cell shape, provides protection, and it is selectively permeable which allows it to only let very specific molecules pass through its surface. The phospholipid bilayer is an important structure because it prevents harmful and unwanted molecules from entering the cell and isolates organelles which helps to maintain the internal environmental homeostasis of the cell.

All cells contain membranes that are selectively permeable, allowing certain things to pass into and leave out of the cell. The process in which molecules of a substance move from an area of high concentration to areas of low concentration is called Diffusion. Whereas Osmosis is the process in which water crosses membranes from regions of high water concentration to areas with low water concentration. While molecules in diffusion move down a concentration gradient, molecules during osmosis both move down a concentration gradient as well as across it. Both diffusion, and osmosis are types of passive transport, which do not require help.

All cells are separated from their surrounding by a cell membrane. The cell membrane regulates what enters and leaves the cell and also aids in the protection and support of the cell. A cell membrane is similar to the walls surrounding your house.

In order for cells and organisms to “live” they need to perform certain tasks such as produce energy through respiration, send messages, maintenance and reproduction. To enable the cell to do so, it contains within small structures called organelles, each organelle is different and carries out a specific function.

The plasma membrane maintains dynamic homeostasis by separating the internal metabolic events of the cell from its external environment and controlling the movement of materials into and out of the cell. The membrane is a double phospholipid membrane, also referred to as a phospholipid bilayer, and has polar hydrophilic ("water loving") phosphate heads around the outside and non polar hydrophobic ("water fearing") fatty acid tails on the inside of the membrane. Slight variations in these structure of the fatty acids in the membrane alter the fluidity of the membrane. Phospholipids with saturated fatty acid pack more tightly, because of the nature of their single carbon bonds. This leads to a more rigid membrane. Unsaturated fatty acids, which have double carbon bonds, limit packing and result in a more flexible membrane. Cholesterol molecules distributed throughout the phospholipid bilayer provide some stability to the plasma membranes of animal cells. At higher temperatures the cholesterol molecules allow the membrane to be firmer, at lower temperatures they allow for flexibility.