Cell Membrane 1
The plasma membrane is made up primarily of a bilayer of
embedded proteins, carbohydrates, glycolipids, and glycoproteins
The amount of cholesterol in animal plasma membranes regulates the fluidity of the membrane and changes based on the temperature of the
cell’s environment.
make up the second major chemical component of plasma membranes.
Proteins
are the third major component of plasma membranes.
Carbohydrates
is a passive process of transport. is the movement of water through a semipermeable membrane according to the concentration gradient of water across the membrane
Osmosis
are used to relate the osmolarity of a cell to the osmolarity of the extracellular fluid that contains the cells
hypotonic, isotonic, and hypertonic
the extracellular fluid has lower osmolarity than the fluid inside the cell, and water enters the cell.
hypotonic situation
refers to the extracellular fluid having a higher osmolarity than the cell’s cytoplasm; therefore, the fluid contains less water than the cell does.
a hypertonic solution
Janie is studying modes of cellular transport this week in her science lab for an upcoming research paper she must write. She must come up with examples of each type of passive transport. Which of the following is NOT an example of passive transport?
A cell in the body is using energy to move large polar molecules through the membrane from an area of low concentration to an area of high concentration with the help of a protein.
The combined gradient of concentration and electrical charge that affects an ion is called its
electrochemical gradient.
is a naturally occurring phenomenon and does not require the cell to exert any of its energy to accomplish the movement.
Passive transport
refers to a membrane’s ability to allow certain molecules or ions to pass through while blocking others.
Selective permeability
Molecules of oxygen and carbon dioxide have no charge and so pass through membranes by
simple diffusion.
describes how an extracellular solution can change the volume of a cell by affecting osmosis.
Tonicity
In an_________, the extracellular fluid has the same osmolarity as the cell.
isotonic solution
in order to pass through the ________, some materials require a specialized structure, like a protein channel.
cell membrane
________ form specialized sites on the cell surface that allow cells to recognize each other.
Carbohydrates
The recognition of self facilitated by the cell membrane plays an important role in ________
the immune response
Choose the best explanation of why the cell membrane is a "fluid mosaic."
It is composed of physically and chemically different parts that move throughout and around the phospholipid bilayer.
The presence of ________ regulates the fluidity of a membrane in animal cells.
cholesterol
describes the structure of the plasma membrane as a mosaic of components—including phospholipids, cholesterol, proteins, and carbohydrates
The fluid mosaic model
The fluid mosaic model of the plasma membrane structure describes the plasma membrane as a fluid combination of
phospholipids, cholesterol, proteins, and carbohydrates.
Chloe is using an electron microscope to view and better understand the composition of the cell membrane. Which of the following components would Chloe NOT see as part of the cell membrane if viewing it under an electron microscope?
Nucleic acids
HIV is able to penetrate the plasma membranes of specific kinds of white blood cells called
T-helper cells and monocytes,
Cell membranes are complex structures. Which of the following statements is FALSE regarding the cell membrane?
The cell membrane consists of all 4 categories of macromolecules.