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Membrane Structure and Function ch5
The plasma membrane is composed primarily of _____
nonpolar, hydrophobic, and directed inwards in the bilayer
The tails of the phospholipids are _____
Electron micrographs support the _____ model of the plasma membrane
The phospholipids form a bilayer around the cell
The amount of phospholipid extracted from red blood cells led researchers to propose that ____
According to the fluid-mosaic model, _____ are partially or wholly embedded in a fluid phospholipid bilayer.
All membranes do not appear the same in electron micrographs (true or false)
The plasma membrane is permeable to some nonlipid substances. (true or false)
According to the fluid-mosaic model the hydrophilic heads of the phospholipids face the intra and extracellular fluids.(true or false)
What is another type of lipid besides phospholipids that are in the plasma membrane.
The permeability of most membranes is reduced by the presence of _____ in the membrane.
A sugar attached to a lipid is called a _____.
glycolipids and gylcoproteins
The plasma membrane is "sugar-coated" by _____.
The proper functioning of some of the membrane proteins depends on the fluidity of the membrane. (true or false)
phospholipids, cholesterol, and glycolipids
Which lipids may be found in the plasma membrane?
The two halves of the plasma ________are not identical.
The plasma membrane is a stiff and rigid structure. (True or false)
species to species, individual to individual, and cell to cell
Glycolipids and glycoproteins vary from __________.
Particular molecules or ions freely cross the plasma membrane with assistance from _____.
glycoproteins and glycolipids
Transplant rejections are the result of the immune system's response to foreign__________________
A person's blood type is determined by the presence of particular _____ in the red blood cells' membranes
Receptor proteins in the plasma membrane do not bind to any kind of _________
What kind of protein is found on the inside surface of the plasma membrane ?
Lipid-soluble molecules move freely across the plasma membrane. (true or false)
What does NOT move freely (without energy or a carrier protein) across the plasma membrane?
What kind of transport requires energy?
During diffusion molecules move from areas of low concentration to areas of high concentration. (true or false)
The hydrophobic tails of the phospholipids in the plasma membrane are what prevent ions and charged molecules from freely crossing the membrane.(true or false)
The sugar you stir into your coffee is an example of a _____.
Osmosis is specifically about the movement of _____ in and out of cells.
If the inside of a cell is 1% NaCl, which solution is isotonic to the cell?
If the inside of a cell is 1% NaCl, which solution is hypertonic to the cell?
A_______solution has fewer solutes than the cell.
Fluids and dissolved substances are transported into the cell by __________.
Solutions that cause cells to neither gain nor lose water are known as ______ solutions.
The central vacuole gains water.
When a plant cell is placed in a hypotonic solution what will occur?
red blood cells that burst after being placed in a hypotonic solution
The term hemolysis refers to ______.
facilitated and active transport
Carrier proteins are required for _____.
What affects water retention by the kidneys, water uptake from tissue fluids by the capillaries, and water absorption from the large intestine?
Molecules move from high concentration to low concentration.
What correctly describes facilitated transport?
carrier proteins are needed, it requires the expenditure of energy. molecules move from areas of low concentration to areas of high concentration. and all of the above.
Which of the following correctly describes active transport?
Insulin leaves insulin-secreting cells by _____.
Macrophages, immune system cells, engulf bacteria by _____.
receptor mediated endocytosis
Specific molecules enter cells by _____.
binding a receptor protein in the plasma membranes
The peptide hormone, follicle stimulating hormone, would activate its specific target cells by _____.
Bacteria, fungi and plants all have an extracellular component called a cell wall. (true or false)
a secondary cell wall
Woody plants are characterized by _____.
The extracellular matrix of animal cells supports them and fills the spaces between the cells.(true or false)
Plant cells are able to exchange materials through _____.
People may get injections of _____, a component of the extracellular matrix of animal cells, to get rid of their wrinkles.
Organs with tissues that get stretched a lot like the heart and bladder are characterized by _____.
Tight junctions between cells make tissues leakproof. (true or false)
Heart cells are able to contract in unison because of the flow of ions through _____.
All cells have a _____.
The plasma membrane allows anything to move freely in or out of the cell. (true or false)
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