What happens to the membrane portion of a vesicle after it fuses with the plasma membrane and releases its contents during exocytosis?
it becomes part of the plasma membrane
it is ejected from the cell
it is transported to another cell
it is digested by lysosomes
Osmosis is the movement of water
across extracellular space
from a large volume to a small volume
throughout the cytoplasm
from a compartment with a high concentration of water to one with low concentration of water
from a region with a low concentration of water to one with a high concentration of water
Which of the following is/are directly involved in the movement of flagella and cilia?
molecular motors
microtubules
ribosomes
molecular motors and microtubules
motors, microtubules, and ribosomes
Which of the following links the extracellular matrix to the cytoskeleton?
cholesterol molecules
transport proteins
actin filaments
integrin proteins
Which of the following would most likely affect the rate of simple diffusion?
temperature
hydroxide ion concentration
isomerization
pH
Biological membranes are composed of
Phospholipids
protein
nucleic acid
phopholipids and proteins
phopholipids, proteins, and nucleic acids
A red blood cell placed in a hypertonic solution will
change color
move to a isotonic solution by diffusion
expand and possibly explode
stay the same shape
shrivel up
Nucelar pores are functionally important because they facilitate
endocytosis
protein synthesis
transcription of mRNA
the movement of mRNA molecules form the nucleus into the cytoplasm
exocytosis
Membrane ion channels are an example of
co-transport
active transport
ion exchangers
facilitated diffusion
carrier transport
Which of the following allow for the exchange of various molecules between plant cells?
xylem
gap junctions
tight junctions
plasmodesmata
desmosomes
Which of the following are found within both mitochondria and chloroplasts?
DNA
centrosomes
DNA and ribosomes
DNA, ribosomes, and centrosomes
The release of a neurotransmitter at a synapse is an example of
phagocytosis
receptor-mediated endocytosis
pinocytosis
The energy for active transport comes from
cytoskeleton
ATP
heat
Which transport mechanism is capable of bringing an entire cell into another, and most likely larger, cell?
Plasma membrane integral proteins may be anchored in place by
cytoskeletal proteins
unsaturated phospholipids
saturated phospholipids
glycoproteins
When a plant cell is exposed to an extracellular solution that is hypotonic, what part of the cell keeps it from rupturing?
chloroplasts
cell wall
plasma membrane
mitochondria
central vacuole
Water cannot flow across phospholipid bilayers by simple diffusion because
phosphate groups within the core of the membrane repel water molecules
fatty acids are too viscous
the concentration of water is always the same inside and outside of a cell
the fatty tails within the core of the membrane is hydrophobic
water molecules are attracted and bind to the polar head groups
A white blood cell can ingest a bacterial cell by the process of
receptor mediated hydrolysis
halitosis
Microtubules are important for
the structure of flagella and cilia
centriole structure
the movement of ions across the plasma membrane
structure of flagella and cilia and centriole
structure of flagella and cilia and centriole and movement of ions
A co-transporter membrane protein, for example the sodium-glucose transporter, typically uses which of the following to move molecules across the plasma membrane?
hydrolysis
glycosylation
ion gradients
A major function of the smooth endoplasmic reticulum is
synthesize proteins destined for secretion
synthesize soluble proteins
sequestration and release of calcium ions
synthesize integral membrane proteins
protein modification
The major function of the mitochondria is to synthesize
proteins
nucleic acids
organic compounds
glucose
Which of the following directly require ATP hydrolysis to function?
Na/K ATPase
ion channels
Na/K ATPase and molecular motors
all
The sodium/potassium ATPase is considered electrogenic because
it produces an electrical potential across the plamsa membrane
hydrolysis of ATP results in the release of negatively charged inorganic phosphate molecules
it requires the presence of a membrane potential for its normal function
an electrical potential is required for ATP synthesis
Which of the following allows for the exchange of ions between animal cells?
Which characteristic of phospholipids contributes to the fluidity of the membrane?
the size of the polar head group
the type of extracellular sugar molecules attached to the protein
the number of peptide bonds
the relative composition of saturated and unsaturated fatty acids
In what way does receptor-mediated endocytosis differ from phagocytosis?
it does not invovle vesicle formation
in transports only fluid
phagocytosis can also expel substances from a cell
it brings into the cell only specifically targeted substances
The function of the rough endoplasmic reticulum is to
synthesize integral membrane proteins and proteins destined for secretion
synthesize soluble, integral membrane, and secretion proteins
Tight junctions
allow for the transfer of water and ions between animal cells
facilitate the diffusion of ions into and out of animal cells
facilitate the diffusion of ions into and out of plant cells
prevent solution/fluid from moving between the plasma membranes of two animal cells
The plant cell wall is mostly composed of
glycagon
amylose
cellulose
glycogen
amylopectin
Which organelle contains digestive enzymes?
Smooth ER
lysosome
Golgi apparatus
Rough ER
Chromatin within the nucleus of a cell contains
histone proteins
RNA
DNA and histone proteins
DNA, histone proteins, and RNA
Which of the following is/are examples of "bulk transport"?
All of the above
Portions of an integral membrane protein that typically pass through biological membranes are in the form of
a 9+2 microtubule arrangement
alpha helices with polar side chains
alpha helices with mostly non-polar side chains
beta-pleated sheets with polar side chains
complex, three dimensional shapes
How do gasses move through plasma membranes?
aquaporins
simple diffusion
The core of a phospholipid bilayer is
anthropomorhpic
polarized
hydrophilic
amphipathic
hydrophobic
Proteins are transported between the cistern of the Golgi apparatus by
intermediate filaments attached to the cis face
vesicles
microfilaments
Free ribosomes within the cytoplasm
synthesize soluble mRNA molecules
The nuclear envelope is notable because it
lacks phospholipids
is constructed with DNA
lacks integral membrane proteins
is a double membrane
How does the sodium/potassium ATPase make the inside of a cell negatively charged?
by pumping more sodium ions out of the cell than pumping potassium ions into the cell
by pumping into the cell a large number of anions
by pumping an equal number of ions in and out of the cell
by pumping out anions
Simple diffusion is best characterized by
the passive movement of a particle from a region of high concentration to low concentration
the active transfer of a particle from a region of low concentration to high
the passive movement of a particle from a region of low concentration to high
the equilibrium state occurring between two compartments of equal concentration
Photosynthesis is performed in which of the following organelles?
christae
Which of the following intracellular structures most likely contributes to the mechanisms of endocytosis and exocytosis?
nucleolus
Phosphorylation of the sodium/potassium pump by ATP hydrolysis
underlies the pumping of Na and K ions by electrostatic repulsion
activates molecular motors
changes the shape/confirmation of the protein, permitting the pumping cycle to move forward
increases the viscosity of the local phospholipid bilayer
attracts Na and k ions to their respective binding sites
Which of the following is not part of the endomembrane system?
nucleus
cholorplast
Sheets of animal cells are held together by
fibronectin
integrins
Where in a eukaryotic cell would polysaccharides most likely be added to a newly synthesized protein?
Which of the following are found in a typical bacterial cell?
ribosomes and cell wall
ribosomes, mitochondria, and cell wall
Active transport of sodium and potassium ions out of and into a cell, respectively, requires
hydrolysis of ATP
movement of phospholipids across the plasma membrane
phosphorylation of ATP
ATP synthesis
the presence of a membrane potential
Which of the following is an example of facilitated diffusion?
transfer of gases from the extracellular space into the cytoplasm
movement of carbon dioxide across the plasma membrane
efflux of sodium and the influx of potassium by the Na/K ATPase
carrier transport of glucose
proton pump extrusion of hydrogen ions
