____ are surface appendages that allow a bacterium to stick to a surface
what is the function of a bacterium’s capsule?
The DNA-containing region of this bacterial cell is indicated by the letter _____.
D the nucleoid region
where is a bacterial cell’s DNA found?
in a bacterium, where are proteins synthesized?
What name is given to the rigid structure, found outside the plasma membrane, that surrounds and supports the bacterial cell?
The _____ is the bacterial structure that acts as a selective barrier, allowing nutrients to enter the cell and wastes to leave the cell.
The structure that regulates the passage of material into and out of this bacterial cell is indicated by the letter _____.
c the plasma membrane
what is the function of the nucleus?
it houses DNA
mitosis refers to
producing new cells
what is the function of the cell membrane?
take in and release materials
Which of the following is most important to transport within a cell?
microtubules and intracellular membranes
all of the above
microtubules and intracellular membranes
when do cells take on their unique characteristics?
during embryonic development
beginning with the nucleus, the first step leading to the synthesis of a polypeptide is
transferring of information from DNA to messenger RNA
WHICH molecules do not normally cross the nuclear membrane?
Which of the following statements about the nuclear envelope is false?
The nuclear envelope is continuous with the Golgi apparatus.
The nuclear envelope is composed of two lipid bilayers.
Molecules pass into and out of the nucleus through nuclear pores.
Nuclear pores are made up of a group of proteins that are collectively called the nuclear pore complex.
the nuclear envelope is continuous with the golgi apparatus
true or false? Large proteins containing a nuclear localization signal (NLS) bind to the nuclear pore and enter the nucleus without any expenditure of energy.
A small protein (molecular weight = 25,000 daltons) is injected into a cell and observed in the nucleus a short time later. What type of transport has taken place?
an experiments to test whether a protein can enter the nucleus, why would proteins be labeled with fluorescent molecules?
to make the proteins easy to see
the ________ signal is only present in the fusion protein that enters the nucleus
Pancreatic cells, which secrete a large amount of digestive enzymes, are labeled with radioactive leucine and then chased for several hours with nonradioactive leucine. Photographic emulsions are prepared at different times during the chase. Where would the black spots appear on an emulsion prepared 3 hours after the pulse?
exterior of the cell
What path does a protein in the secretory pathway take, starting from its site of synthesis?
rough ER, golgi apparatus, secretory vesicles, plasma membrane
What scientific hypotheses can be tested by a pulse-chase experiment?
movement of molecules through a cell over time
True or false? Proteins produced during the “chase” phase of a pulse-chase experiment are labeled with radioactive material.
what is the first step in a pulse-chase experiment
incubating cells with a labeled molecule
Which organelle plays a role in intracellular digestion?
3 functions of smooth er
Calcium ion storage
function of rough er
function of golgi apparatus 2
protein modification and sorting
2 function of lysosomes
which proteins are synthesized by bound ribosomes?
ER protein, insulin, lysomal enzyme
the cilia and flagella of a eukaryotic cells are composed of
which of these cell junctions form a barrier to the passage of materials?
the primary role of ______ is to bind animal cells togeher
______ aid in the coordination of the activities of adjacent animal cells
Gap junctions (communicating)
choose the letter that indicates the organelle that contains most of a cell’s DNA
C the nucleus contains most of a cell’s DNA
which of these organelles carries out cellular respiration
which of these is the double membrane that encloses the nucleus
e (nucleur envelop)
The _____ is composed of DNA and protein
ribosomal subunits are manufactured by the
_____ are the sites of protein synthese
Which of these manufactures cellular membranes by adding membrane proteins and phospholipids to its own membrane?
rough endoplasmic reticulum
the ______ is a selective barrier, regulating the passage of material into and out of the cell
the _____ is a selective barrier, regulating the passage of material into and out of the cell
where is calcium stored
smooth endoplasmic reticulum
which of these structures stores, modifies, and packages products?
A the golgi apparatus modifies, stores, and packages products of theER
which of these are hollow rods that shape and support the cell?
_____ are identical in structure to centrioles
what organelle produces H2O2 as a by product
which of these provides the cell with structural support?
D microfilaments are a component of the cytoskeleton
structures found in only plant cells
cellulose cell wall
structure found only in animal cell
structures found in both animal and plant cells
what does the plant cell wall do
its a strong protective structure made from cellulose fibrils
what does the central vacuole do
it regulates cytoplasm composition, creates internal pressure, and stores cell compounds
what does chloroplst do
makes sugar by converting light energy into chemical energy
produces chemical energy (tap) the can power the cell
golgi apparatus function?
modifies and packages proteins
cell strucure of prokaryotic?
lysosome, mitochondria, nucleolus
cell structue of both prokaryotic and eukaryotic
ribosomes plasma membrane flagella