-
site of phospholipid synthesis and calcium storage
smooth ER
-
organizing center for microtubules
centriole
-
site of degradation of proteins and cellular components
lysosome
-
site where proteins are heavily modified with carbohydrates
Golgi apparatus
-
generates the ATP needed for cell activities
mitochondria
-
contains pores through which protein and RNA can be transferred
nucleus
-
defines the boundary of all cells
plasma membrane
-
initial site of synthesis specifically for membrane proteins
rough ER
-
connects the cytoplasms of two different animal cells
gap junction
-
used in translating an RNA into a protein
ribosome
-
what limits the size of cells
the need for a surface area of sufficient area to support he cells metabolic needs
-
in microscopy, the term "resolution" refers to what?
the ability to distinguish two different points as separate objects
-
what is most likely pathway taken by a newly synthesized protein that will be secreted?
ER->Golgi->vesicles that fuse w/plasma membrane
-
In order for a protein to be an integral membrane protein it would have to be
amphipathic, with at least one hydrophobic region
-
the reactivity of an atom depends on the
presence of unpaired electrons in valence shell of the atom
-
Nitrogen forms 3 covalent bonds. How many electrons are found in its outermost shell?
5
-
Phosphorus-32 (radioactive) has_____ than phosphorus-35
3 few neutrons
-
when two atoms have the same electronegativity, they will interact to form_____
Non-Polar Covalent Bonds
-
Water is able to form hydrogen bonds because
bonds that hold together the atoms in a water molecule are polar covalent bonds
-
What is the reason why hydrocarbons are not soluble in water?
the majority of their bonds are nonpolar covalent carbon-to-hydrogen linkages
-
what do isomers have in common?
molecular mass
-
what bon type stabilizes Alpha helices and beta sheets secondary structures in proteins?
hydrogen bonds
-
ATP generally energizes a cellular process by:
coupling free energy released by ATP hydrolysis to energy needed by other reactions
-
A molecule with the chemical formula C16H32O16 is probably a:
carbohydrate
-
Saturated fatty acids
have a higher ratio of hydrogen to carbon than do unsaturated fatty acids
-
The tertiary structure of a protein is the
unique three-dimensional shape of the fully folded polypeptide
-
Which one of the following functional groups decreases the solubility of organic compounds in water?
-CH3
-
Polysaccharides serve what important functions in cells?
energy storage
-
A nucleotide is made of which of the following chemical components?
a nitrogenous base, a phosphate group, and a ribose sugar
-
Which of the following would probably not be affected when a protein is denatured?
primary structure
-
Polymers are broken down into monomers by what general process?
Hydrolysis
-
How does the infectious form of prion that causes mad cow disease, PrPc, differ from the non-infectious form?
The infectious form has a different 2 and 3 structure
-
what type of reaction builds up biological polymers?
condensation
-
the mechanism of enzyme action is:
lowering the energy of activation for a reaction
-
Cells are constantly using energy to build up things. Where does this energy come from?
Catabolic reactions
-
Which of these statements about enzyme inhibitors is true?
A noncompetitive inhibitor changes the shape of the active site
-
In a lab experiment you discover that an enzyme-catalyzed reaction has a change G of -20kcal/mol. If you double the amount of enzyme in the rxn, what will be the change G for the new rxn?
-20 kcal/mol
-
The active site of an enzyme is the region that_____
is involved in the catalytic rxn of the enzyme
-
THe two strands of DNA are bonded together by hydrogen bonds btwn what?
opposite complementary nitrogenous bases
-
When two atoms bond together by sharing a pair of electrons unequally which results in partial charge distribution, the bond is considered what?
polar covalent
-
Why is there so much energy in an ATP molecule?
the negative charges are crowded in the 3 high energy phosphate bonds
-
The quartenary structure of a protein is the:
overall protein structure resulting from the aggregation of two or more polypeptide subunits
-
Steroids are classified as lipids, and are all derived from what common precursor molecule?
cholesterol
-
How many hydroxyl groups are on a glycerol molecule?
3
-
How does a competitive inhibitor affect the typical graph of rxn rate versus substrate concentration in an enzyme saturation experiment?
increases Km but leaves Vmax unchanged
-
What specific type of macromolecule is needed to form the membrane structures?
phospholipids
-
what is entropy?
state of disorder
-
The binding of an allosteric inhibitor to an enzyme causes the rate of product formation by the enzyme to decrease. Which best explains why this decrease occurs?
the allosteric inhibitor binds to allosteric site which causes a structural change in the enzyme that prevents the substrate from binding at the active site
-
The fluid mosaic model of the membrane proposed that
membranes consist of protein molecules embedded in a fluid bilayer of phospholipids
-
In order for a protein to be an integral membrane protein it would have to be
amphipathic, with at least one hydrophobic region
-
what kinds of molecules pass through a cell membrane most easily?
small and hydrophobic
-
which of the following membrane activities require energy from ATP hydrolysis?
Na+ ions moving out of a mammalian cell bathed in physiological saline
-
white blood cells engulf bacteria through what process?
phagocytosis
-
the sodium-potassium pump is called an electrogenic pump because it
contributes to the membrane potential
-
ions diffuse across membranes through specific ion channels
down their electrochemical gradients
-
The sodium-potassium pump in animal cells requires cytoplasmic ATP to pump ions across the plasma membrane. When the proteins of the pump are first synthesized in the rough ER, what side of the ER membrane will the ATP binding site be on?
It will be on the cytoplasmic side of the ER
-
THe liver is involved in detoxification of many poisons and drugs. Which of the following structures is primarily involved in this process and therefore abundant in liver cells?
smooth ER
-
Transporters, in contrast to channels, work by ________
specific binding to solutes
-
If Na+ channels are opened in a cell that was previously at rest, how will the resting membrane potential be affected?
it becomes more positive
-
Signal sequences that direct proteins to the correct compartment are_____________
encoded in the amino acid sequence and sufficient for targeting a protein to its correct destination
-
What is the role of the nuclear localization sequence in a nuclear protein?
It is bound by cytoplasmic proteins that direct the nuclear protein to the nuclear pore.
-
An individual transport vesicle_________
will fuse with only one type of membrane
-
location of signal-recognition particle
cytosol
-
location of protein translocator
ER membrane
-
-
location of SRP receptor?
ER membrane
-
location of active site of signal peptidase
ER lumen
-
Which of the following statements about the protein quality control system in the ER is false?
proteins that are misfolded are degraded in the ER lumen
-
Vesicles from the ER enter the Golgi at the
cis Golgi network
-
Which of the following statement about the functions of the centrosome is false?
microtubules emanating from the centrosome have alternating polarity such that some have their plus end attached to the centrosome while others have their minus end attached to the centrosome
-
Which of the following statement regarding dynamic instability is false?
the newly freed tubulin dimers from a shrinking microtubule can be immediately captured by growing microtubules and added to their plus end
-
For both actin and microtubule polymerization, nucleotide hydrolysis is important for_______
decreasing the binding strength between subunits on filaments
-
which of the following conditions is likely to decrease the likelihood of skeletal muscle contraction
addition of a rug that blocks Ca2+ binding to troponin
-
Which of the following contain he 9 + 2 arrangement of microtubules, consisting of nine doublets surrounding a pair of singles
both flagella and motile cilia
-
movement of vesicles within the cell depends on what cellular structures?
microtubules and motor proteins
-
4 things you'll find in a plant cell
- cell wall
- central vacuole
- chloroplasts
- mitochrondria
-
2 things associated with a prokaryotic cell
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