In a hypotonic solution, an animal cell will
Swell or burst
The following pictures are examples of which of the following?
Active transport
Diffusion
Facilitated diffusion
Osmosis
The selective permeability of biological membranes is dependent on which of the following?
the types of carbohydrates on the surface of the membrane
the type of transport proteins that are present
the number of mitochondria in the cell
Describe two roles of proteins in the cell membrane
Channel proteins for cell transport. Glycoproteins for cell recognition.
What may happen to a person who has too little cholesterol in the cell membranes?
At low temperatures, the cell membrane will become rigid. At high temperatures, the cell membrane will be too fluid. Less structure without cholesterol.
All of the following molecules are part of the cell membrane except
Lipids
Proteins
Phosphate groups
Nucleic acids
Why is the cell membrane called the fluid mosaic model?
"Mosaic" = many small components. "Fluid" = lateral movement.
The presence of cholesterol in the plasma membranes of some animals
makes the membrane less flexible for sustaining pressure
makes the animal more susceptible to circulatory disorders
lets the membrane stay fluid when cell temperature drops
enables the membrane to more easily break down fats
A cell whose cytoplasm has a concentration of 0.02M glucose is places in a test tube of water containing 0.02M glucose. Which of the following describes the tonicity of the external solution relative to the cytoplasm of the cell?
Isotonic
A patient has had a serious accident and lost a lot of blood. Equal to the blood volume lost, the patient is given distilled water. What will be the most probable result of this diffusion?
RBCs will swell - blood fluid is hypotonic
RBCs will shrivel - blood fluid is hypotonic
RBCs will shrivel - blood fluid is hypertonic
RBCs will burst - blood fluid is hypertonic
Endocytosis moves materials _______ a cell via _________
Out of; membranous vesicles
Out of; facilitated diffusion
Into; membranous vesicles
Into; facilitated diffusion
What are the membrane structures that function in active transport?
Cholesterol
Phospholipids
Proteins
Carbohydrates
You are a biochemist making a new drug. For the drug to work, it must enter the cytoplasm of specific cells. Which of the following is NOT a factor that determines whether the molecule enters the cell?
Lipid composition of the target cells' plasma membrane
Charge on the drug molecule
Size of the drug molecule
Polarity of the drug molecule
The solutions in the arms of the U-tube are separated at the bottom of the tube by a selectively permeable membrane. The membrane is permeable to water but not to the dots. What is the change in the picture due to?
Facilitated diffusion
Diffusion
Endocytosis
Osmosis
The interior of the phospholipid bilayer is
Hydrophilic
Water
Hydrophobic
Composed of fatty acids
All of the following membrane activities require energy from ATP hydrolysis except
Active transport
Phagocytosis
Facilitated diffusion
Na+ ions moving out of the cell
In a hypertonic solution, an animal cell will
Shrivel up
Celery stalks are immersed in fresh water for several hours and become stiff and hard. Similar stalks left in salt solution become limp and soft. From this we can deduce that the cells of the celery stalks are
hypotonic to both fresh water and salt water
hypotonic to fresh water but hypertonic to salt solution
hypertonic to both fresh water and salt water
isotonic with fresh water but hypotonic to salt solution
All of the following processes take materials into the cell except
Pinocytosis
Endocytosis
Exocytosis
Facilitated diffusion
The movement of a substance across a biological membrane against its concentration gradient with the help of energy input is
Active transport
Which of the following statements is correct about diffusion?
it requires an expenditure of energy by the cell
an active process that follows low to high concentration
it is very rapid over long distances
a passive process that follows high to low concentration
According to the fluid mosaic model of cell membranes, which of the following is a true statement about membrane phospholipids?
they frequently flip-flop from one side to another
they have hydrophilic tails in the interior of the membrane
they can move laterally along the plane of the membrane
they occur in an uninterrupted bilayer
Oxygen crosses a plasma membrane by
Active transport
Osmosis
Diffusion
Phagocytosis
White blood cells engulf bacteria through what process?
Osmosis
Phagocytosis
Exocytosis
Pinocytosis
What kinds of molecules pass through the cell membrane most easily?
larger and nonpolar
small and polar
large and polar
small and nonpolar
The membrane activity most nearly opposite to exocytosis is
Facilitated diffusion
Osmosis
Active transport
Phagocytosis
Which of the following would likely move through the lipid bilayer of a plasma membrane most rapidly?
K+ (potassium ion)
amino acids
starch
CO2 (carbon dioxide)