Living cells are highly regulated.
a. Describe the structure of the plasma membrane.
b. Explain how the plasma membrane contributes to the regulation of the cell.
A. The plasma membrane consists of a phospholipid bilayer that has some spaces with cholesterols which determine the fluidity of the plasma membrane. It also has proteins that determine which molecules and nutrients can enter the cytoplasm of the cell. These proteins can be selective and help regulate. There are carrier proteins and channel proteins. B. The plasma membrane regulates cells by allowing only some things into the cell. Using carrier proteins and channel proteins the cell can regulate what goes into the cell and what comes out.
A. Like all other cellular membranes, the plasma membrane consists of both lipids and proteins. The fundamental structure of the membrane is the phospholipid bilayer, which forms a stable barrier between two aqueous compartments. In the case of the plasma membrane, these compartments are the inside and the outside of the cell. Proteins embedded within the phospholipid bilayer carry out the specific functions of the plasma membrane, including selective transport of molecules and cell-cell recognition. B. The plasma membrane is very selective and thus will regulate what is exported from the cell and what gets imported. For examle, steroids are very nonpolar and thus can easily diffuse through the membrane and thus affect transcription within a cell whilst peptide hormones bind to receptors on a cell's surface which starts a cascade of transducers that will trigger more immediate changes in a cell.
The plasma membrane is made of a complicated phospholipid bilayer. this bilayer is hydrophillic and hydrophobic. on it are the proteins (like the crrier and transport proteins) that traffic molecules from one side to the other.
the plasma membrane is selectively permeable, meaning it can let some things in and others out. but this decision is made based on the size of the molecule wanting to get through. this can happern by diffusion or active transport.
Some of the molecules we talked about that can enter freely are like 02 molecules some that need carriers would be like larger molecules like Na+ and K+ which require pumps.Also permeability depends on the environment and can be affected by temperature.
The plasma membrane is made out of a double phospholipid bi layer that is made out of hydrophilic heads and hydrophobic tails. It aslo contains proteins and as integral and peripheral proteins that help for the transport of molecules across the membrane. The most prominent being the sodium potassium pump.
The Plasma membrane is a selectively permeable membrane that regulates what comes into the cell and what goes out of the cell. For example nonpolar steroids easily penetrate the membrane. in order for the molecule to pass through the membrane thy need to be "recognized" by a receptor protein. Osmosis regulates the water in the cell. Through different types of active and passive transport the plasma membrane regulates the cell.
A. The plasma membrane consists of a phospholipid bi-layer embedded with scattered proteins and cholesterol molecules located inside the hydrophobic middle of the phospholipid bi-layer. The fluidity of the membrane is based on the saturated and unsaturated fatty acids of the phospholipids. Cholesterol maintains the rigidity of the membrane in cool and hot temperatures. And transport proteins are used to transport specific ionic particles through the membrane. Other proteins are used to connect cells together and for cell recognition.
B. Nonpolar molecules such as hrdrocarbons and oxygen are hydrophobic and can dissolve in the membrane and pass through easily. Few ionic particles such as sugars and tiny water molecules can slowly pass through.(these molecules are essential to the cell) Other ionic molecules must pass through transport proteins. These transport proteins are unique in size and function in order to regulate what goes in and out of the cell. Some proteins passively transport molecules while others use ATP to pump particles through the membrane like Na, K, Ca, and Cl ions, in order to regulate their concentrations needed by the cell. Other proteins use receptors to identify molecules entering the cell, or to send signals to the nucleus.
cellular membranes are made up of a phospholipid bilayer. The phospholipid bilayer consists of phospholipids, which each have a hydrophilic head and a hydrophobic tail. The hydrophobic tails bind together to form the interior of the bilayer, while the hydrophilic heads face the outside. In between the crevices of the bilayer lie cholesterol, which stabilizes the phospholipids. Carbohydrates also bind to some of the phospholipids.In addition, carrier and transport proteins help regulate which molecules can enter and exit the cell.
Cell membranes are selectively permeable, meaning they allow certain molecules to enter the cell and disallow certain others. Small nonpolar or hydrophobic molecules can enter a cell membrane with relative ease, examples being carbon dioxide and fatty acids respectively. Molecules that are either large, polar, or hydrophyllic need energy to enter a cell. This energy is provided by ATP or by specific transport proteins. Macromolecules cannot enter the membrane without the use of ATP, and ions such as Na+ and Cl- cannot enter the membrane without transport proteins. Several factors contribute to the permeability of a cell membrane, including the amount of channel proteins in the membrane and how many of them are open as well as environmental conditions such as temperature.
The plasma membrane is made up of a phospholipid bilayer with cholesterol and peripheral and integral proteins. The phospholipids have hydrophilic heads and hydrophobic tails. The tails come together in a hydrophobic effect. The proteins facilitate transport across the membrane.
The plasma membrane regulates what enters the cell and what exits. Polarity is also taken into account when considering what could pass through the membrane. The heads of the phospholipids are hydrophillic, which means they are polar. Therefore, if polar molecules attempt to pass through the membrane, they will either be attracted or repelled. Nonpolar molecules that are small enough will pass through the membrane freely. However, ions or larger molecules, such as potassium ions, could pass through the plasma membrane using ATP as an energy source
a. the plasma membrane is composed from a phospholipid bi-layer that contains proteins and cholesterol molecules located inside the phospholipid bi-layer. cholesterol makes up the rigidity of the membrane in different temperature. some proteins are used to connects same types of cells together by cell recognition and for the active transport of molecules inside and outside the plasma membrane. as for the fluidity of the membrane, it all is based on what different saturated an unsatured fatty acids there are on yhe phospholipids.
b. cell membranes are selectively permeable that allows them to transport specific molecules in and out depending on some key featured like size. small molecule can enter easily because of the size and so can any hydropobic molecules. as for larger and hydrophilic moceluces, they need atp to be able to get into the cell because they are large. different factors effect the permeability of the membrane, such as the surrounding environment, and how many open chanel protions there are on the membrane.
The plasma membrane of the cell is often described as "selectively permeable;" that is, the plasma membrane is designed so that only certain substances are allowed to travel through its borders. The plasma membrane is composed of two layers of molecules called phospholipids. Each phospholipid molecule consists of a phosphate "head" and two fatty acid chains that dangle from the head. The plasma membrane does the major function of regulating transportation of substances from inside the cell to the outside and vice versa. It regulates what enters and exits the cell, depending on size and polarity. When substances enter the p.m without the use of energy this is called passive transport. If they use pumps and ATP it is called active transport. Macromolecules and ions such as Na+ and Cl- cannot enter the membrane without the use of ATP so they have to use transport proteins.
A. The plasma membrane consists of a phospholipid bilayer that has some spaces with cholesterols which determine the fluidity of the plasma membrane. It also has proteins that determine which molecules and nutrients can enter the cytoplasm of the cell. These proteins can be selective and help regulate. There are carrier proteins and channel proteins.
ReplyDeleteB. The plasma membrane regulates cells by allowing only some things into the cell. Using carrier proteins and channel proteins the cell can regulate what goes into the cell and what comes out.
A. Like all other cellular membranes, the plasma membrane consists of both lipids and proteins. The fundamental structure of the membrane is the phospholipid bilayer, which forms a stable barrier between two aqueous compartments. In the case of the plasma membrane, these compartments are the inside and the outside of the cell. Proteins embedded within the phospholipid bilayer carry out the specific functions of the plasma membrane, including selective transport of molecules and cell-cell recognition.
ReplyDeleteB. The plasma membrane is very selective and thus will regulate what is exported from the cell and what gets imported. For examle, steroids are very nonpolar and thus can easily diffuse through the membrane and thus affect transcription within a cell whilst peptide hormones bind to receptors on a cell's surface which starts a cascade of transducers that will trigger more immediate changes in a cell.
Farah, what are some of the molecules we talked about that can enter freely and what requires carriers? What factors contribute to the permeability?
ReplyDeleteLara, you too. What are some more factors affecting permeability?
The plasma membrane is made of a complicated phospholipid bilayer. this bilayer is hydrophillic and hydrophobic. on it are the proteins (like the crrier and transport proteins) that traffic molecules from one side to the other.
ReplyDeletethe plasma membrane is selectively permeable, meaning it can let some things in and others out. but this decision is made based on the size of the molecule wanting to get through. this can happern by diffusion or active transport.
Some of the molecules we talked about that can enter freely are like 02 molecules some that need carriers would be like larger molecules like Na+ and K+ which require pumps.Also permeability depends on the environment and can be affected by temperature.
ReplyDeleteThe plasma membrane is made out of a double phospholipid bi layer that is made out of hydrophilic heads and hydrophobic tails. It aslo contains proteins and as integral and peripheral proteins that help for the transport of molecules across the membrane. The most prominent being the sodium potassium pump.
ReplyDeleteThe Plasma membrane is a selectively permeable membrane that regulates what comes into the cell and what goes out of the cell. For example nonpolar steroids easily penetrate the membrane. in order for the molecule to pass through the membrane thy need to be "recognized" by a receptor protein. Osmosis regulates the water in the cell. Through different types of active and passive transport the plasma membrane regulates the cell.
A. The plasma membrane consists of a phospholipid bi-layer embedded with scattered proteins and cholesterol molecules located inside the hydrophobic middle of the phospholipid bi-layer. The fluidity of the membrane is based on the saturated and unsaturated fatty acids of the phospholipids. Cholesterol maintains the rigidity of the membrane in cool and hot temperatures. And transport proteins are used to transport specific ionic particles through the membrane. Other proteins are used to connect cells together and for cell recognition.
ReplyDeleteB. Nonpolar molecules such as hrdrocarbons and oxygen are hydrophobic and can dissolve in the membrane and pass through easily. Few ionic particles such as sugars and tiny water molecules can slowly pass through.(these molecules are essential to the cell) Other ionic molecules must pass through transport proteins. These transport proteins are unique in size and function in order to regulate what goes in and out of the cell. Some proteins passively transport molecules while others use ATP to pump particles through the membrane like Na, K, Ca, and Cl ions, in order to regulate their concentrations needed by the cell. Other proteins use receptors to identify molecules entering the cell, or to send signals to the nucleus.
cellular membranes are made up of a phospholipid bilayer. The phospholipid bilayer consists of phospholipids, which each have a hydrophilic head and a hydrophobic tail. The hydrophobic tails bind together to form the interior of the bilayer, while the hydrophilic heads face the outside. In between the crevices of the bilayer lie cholesterol, which stabilizes the phospholipids. Carbohydrates also bind to some of the phospholipids.In addition, carrier and transport proteins help regulate which molecules can enter and exit the cell.
ReplyDeleteCell membranes are selectively permeable, meaning they allow certain molecules to enter the cell and disallow certain others. Small nonpolar or hydrophobic molecules can enter a cell membrane with relative ease, examples being carbon dioxide and fatty acids respectively. Molecules that are either large, polar, or hydrophyllic need energy to enter a cell. This energy is provided by ATP or by specific transport proteins. Macromolecules cannot enter the membrane without the use of ATP, and ions such as Na+ and Cl- cannot enter the membrane without transport proteins. Several factors contribute to the permeability of a cell membrane, including the amount of channel proteins in the membrane and how many of them are open as well as environmental conditions such as temperature.
The plasma membrane is made up of a phospholipid bilayer with cholesterol and peripheral and integral proteins. The phospholipids have hydrophilic heads and hydrophobic tails. The tails come together in a hydrophobic effect. The proteins facilitate transport across the membrane.
ReplyDeleteThe plasma membrane regulates what enters the cell and what exits. Polarity is also taken into account when considering what could pass through the membrane. The heads of the phospholipids are hydrophillic, which means they are polar. Therefore, if polar molecules attempt to pass through the membrane, they will either be attracted or repelled. Nonpolar molecules that are small enough will pass through the membrane freely. However, ions or larger molecules, such as potassium ions, could pass through the plasma membrane using ATP as an energy source
a. the plasma membrane is composed from a phospholipid bi-layer that contains proteins and cholesterol molecules located inside the phospholipid bi-layer. cholesterol makes up the rigidity of the membrane in different temperature. some proteins are used to connects same types of cells together by cell recognition and for the active transport of molecules inside and outside the plasma membrane. as for the fluidity of the membrane, it all is based on what different saturated an unsatured fatty acids there are on yhe phospholipids.
ReplyDeleteb. cell membranes are selectively permeable that allows them to transport specific molecules in and out depending on some key featured like size. small molecule can enter easily because of the size and so can any hydropobic molecules. as for larger and hydrophilic moceluces, they need atp to be able to get into the cell because they are large. different factors effect the permeability of the membrane, such as the surrounding environment, and how many open chanel protions there are on the membrane.
The plasma membrane of the cell is often described as "selectively permeable;" that is, the plasma membrane is designed so that only certain substances are allowed to travel through its borders. The plasma membrane is composed of two layers of molecules called phospholipids. Each phospholipid molecule consists of a phosphate "head" and two fatty acid chains that dangle from the head.
ReplyDeleteThe plasma membrane does the major function of regulating transportation of substances from inside the cell to the outside and vice versa. It regulates what enters and exits the cell, depending on size and polarity. When substances enter the p.m without the use of energy this is called passive transport. If they use pumps and ATP it is called active transport. Macromolecules and ions such as Na+ and Cl- cannot enter the membrane without the use of ATP so they have to use transport proteins.