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Cell or Plasma Membranes
Every cell has a cell membrane (plasma membrane) that separates the interior of the cell from the outside environment. One of the most important functions of this biological membrane is to protect the cell from outside threats by controlling the movement of substances in and out of the cell.
1,116 Questions
Plasma membrane exhibits chemically gated ion channels?
Chemically gated ion channels in the plasma membrane are sensitive to specific molecules that bind to them, causing the channel to open or close. This allows for the controlled movement of ions across the membrane in response to chemical signals, regulating processes such as muscle contraction and neurotransmission.
The multidrug resistant pumps in many bacterial cell membranes cause?
The multidrug resistant pumps in bacterial cell membranes can cause resistance to multiple antibiotics by actively pumping them out of the cell, reducing the effectiveness of antibiotic treatment. This can make infections more difficult to treat and lead to the development of superbugs that are not easily killed by antibiotics.
What might happen if a disease caused a plasma membrane to thicken?
If a disease caused a plasma membrane to thicken, it could disrupt the exchange of molecules in and out of the cell. This could lead to issues with cellular communication, nutrient uptake, and waste removal. Ultimately, it could result in cell dysfunction and potential cell death.
Does the plasma membrane allow all substances to pass into and out of the cell?
No, the plasma membrane is semipermeable, meaning it allows some substances to pass through while blocking others. This selectivity is crucial for maintaining cell function and regulating the internal environment of the cell.
Are cell membranes permeable or semi-permeable?
Cell membranes are semi-permeable, meaning they allow certain substances to pass through while blocking others. This selectivity is facilitated by proteins embedded in the membrane that regulate the passage of specific molecules based on size, charge, and other properties.
Do plant cells have a cell wall instead of the plasma membrane?
Yes because the cell membrane is needed to regulate the flow of material in and out of the cell.
Also, when the plant cell requires to undergo plasmolysis, the cell membrane enables the process, because it is not rigid.
Is plasma membrane animal or plant cell?
Yes. However, the central vacuole is a better factor in determining the plant status of an organism.
yes
What type of molecule has a carboxyl head and makes up cell membranes?
A phospholipid molecule has a carboxyl head and makes up cell membranes. Phospholipids consist of a hydrophilic head (containing a phosphate group and a carboxyl group) and two hydrophobic tails, which help form the lipid bilayer of cell membranes.
What would be the cell membrane of a computer?
In a computer, the closest analogy to a cell membrane would be the firewall or security software that acts as a barrier between the internal system and external threats, regulating the flow of data in and out of the computer.
What floats around the cell membrane?
Various molecules and ions, such as lipids, proteins, and carbohydrates, float around the cell membrane. These molecules are important for cell communication, transport, and structural support. Additionally, water molecules can freely move within and around the cell membrane.
Transport across cell membranes that requires energy or ATP?
Active transport is the process of transporting molecules across a cell membrane against their concentration gradient, requiring energy in the form of ATP. This allows substances to move from low to high concentration, maintaining cellular homeostasis and enabling functions such as nutrient uptake and waste removal.
Yes, most animal cell membranes have protein pumps known as sodium-potassium pumps that actively transport sodium ions out of the cell and potassium ions into the cell. This helps maintain the cell's electrochemical gradient essential for various cellular functions.
Do ribosomes have cell membranes?
No, ribosomes do not have cell membranes. Ribosomes are organelles responsible for protein synthesis in cells and are made up of ribosomal RNA and proteins. They are typically found floating freely in the cytoplasm or attached to the endoplasmic reticulum.
When ions move across a plasma membrane what will happen?
When ions move across a plasma membrane, it can create changes in membrane potential and can trigger physiological responses within the cell. The movement of ions is essential for functions such as nerve signaling, muscle contraction, and maintaining osmotic balance. Transport of ions across the membrane is tightly regulated to maintain cellular homeostasis.
Does Water move into or out of a membrane bound hypotonic vesicle?
Water moves into a membrane-bound hypotonic vesicle through the process of osmosis. In a hypotonic solution, the concentration of solutes outside the vesicle is lower than inside, causing water to flow into the vesicle to balance the concentration gradient.
Why do you think animal cells have cell membranes instead of cell walls?
Cell walls hold cells stiff so trees can grow tall. Cell membranes are flexible so animals can bend and move about. No tree can scratch itself where it itches. There is a disease that makes people so stiff they can not move. That would happen to everyone if they had cell walls.
What type of molecule is embedded in cell membranes?
Proteins are often found embedded in the cell membrane. These proteins are called transmembrane or inter-membrane proteins.
Cholesterol molecules are also found embedded in the hydrophobic interior of the cell membrane in many species
Gases such as oxygen and carbon dioxide cross the plasma membrane by?
simple diffusion, a passive process where molecules move from an area of higher concentration to an area of lower concentration. This allows gases to move across the plasma membrane to maintain equilibrium between the cell and its surroundings.
Steroid hormones cannot pass through the plasma membranes of their target cells?
False. Steroid hormones are lipophilic molecules that can pass through the plasma membrane of target cells. Once inside the cell, they bind to specific receptors located in the cytoplasm or nucleus, leading to changes in gene expression and cellular responses.
What molecule would not be found in an animal plasma membrane?
Cellulose, which is a carbohydrate found in the cell walls of plants, would not be found in an animal plasma membrane. Animal plasma membranes primarily consist of phospholipids, cholesterol, and proteins.
What are the 3 types of cellular transport that the plasma membrane controls?
There are many different processes that are controlled by the plasma membrane aka as the cell membrane.
- Selective Permeable -- this means that only certain things will be allowed to enter or to leave the cell membrane.
- Active transport -- this process is where ATP is required. An example of this type of transport is when there is particles that are too large to passively go through the membrane will need to be carried by glucose, and through protein carriers.
- Passive transport -- this is where no actual ATP is required, it flows quite freely through the membrane. One example of this type is diffusion.
How many layers of phospholipids are there in the plasma membrane?
There are two layers of phospholipids in the plasma membrane, with each layer composed of phospholipid molecules arranged in a bilayer structure. This bilayer provides the membrane with its characteristic flexibility and semi-permeability.
What is meant by the fluidity of the cell membrane?
The cell membrane is made up of a phospholipid bi-layer (a phospholipid has a polar head, and two non polar tails). the membrane's structure makes it so that the heads are opposite each other, and their tails intertwine, so it look like this:
( ) ( ) ( ) ( ) ( ) <-- polar heads
| | | | | | | | | | | | | | | | | |
| | | | | | | | | | | | | | | | | | <-- 2 non polar tails
| | | | | | | | | | | | | | | | | |
( ) ( ) ( ) ( ) <-- the other side of the membrane (polar heads)
the spaces that the tails create keep the membrane's fluidity.
What ships products to plasma membrane or outside or other organelles?
The endoplasmic reticulum packages and ships products to the plasma membrane, outside the cell, or to other organelles through vesicles. These vesicles bud off from the endoplasmic reticulum and travel to their destination to deliver their cargo.
