Which kind of cells have their DNA in a single, circular molecule of
DNA devoid of any surrounding membrane or histone proteins?
bacteria
protozoa insects flowering plants
yeast

bacteria

Plant cells often have a large membrane-bound sac that is used for
storing water and other substances. This organelle is called a
nucleus
chloroplast golgi body centriole
central vacuole

central vacuole

Membrane-bound organelles that contain powerful digestive enzymes are
known as
lysosomes
plastids vacuoles liposomes
ribosomes

lysomes

Flattened sacks of membranes apparently involved in the packaging and
export of molecules synthesized elsewhere in the cell are know as
golgi bodies
microbodies pinocytic vesicles vacuoles
chromosomes

golgi bodies

Mammalian blood contains the equivalent of 0.15M NaCl. Seawater
contains the equivalent of 0.45M NaCl. What will happen if red blood
cells are transferred to seawater?
the blood cells
will expend ATP for active transport of NaCl into the
cytoplasm water will leave the cells, causing them to
shrivel and collapse NaCl will passively diffuse into the
red blood cells NaCl will be exported from the red blood
cells by facilitated diffusion. the blood cells will take
up water, swell, and eventually burst

water will leave the cells, causing them to shrivel and collapse

Receptor-mediated endocytosis (RME) is different from pinocytosis or
phagocytosis because
phagocytosis takes in
only liquid matter, while RME takes in solids RME is not
specify and takes in any solid matter pinocytosis takes in
only solid matter, while RME takes in liquid phagocytosis
is designed to take in only living organisms RME depends on
specific receptor proteins for specific molecules that trigger
endocytosis

RME is not specify and takes in any solid matter

The "powerhouse" organelle involved in the oxygen-requiring
process by which the energy in macromolecules is converted/stored into
ATP is the
nucleus
lysosome ER mitochondria
chloroplast

mitochondria

Which of the following are capable of converting light energy to
chemical energy (ultimately in the form of carbohydrates)?
leucoplast
peroxisomes golgi bodies chloroplasts
mitochondria

chloroplasts

Lipids are the only class of macromolecules that contain
amino acids
nucleic acids fatty acids phosphate
groups sugars

fatty acids

Biological membranes contain bilayers of which of the following lipids?
phospholipids
oils prostaglandins triglycerides
cholesterol

phospholipids

Prokaryotic cells in the genus Sulfolbus are in the Domain
Archaea, and are commonly found in geothermal environments, with an
optimum growth temperature of above 80 C. Which of the following
features is most likely to allow Archaea to thrive at such temperatures?
archaea use the
heat from their environment to produce ATP archaea are not
adaptable to changing environmental temperatures archaeal
membranes contain high concentrations of saturated lipids
archaeal membranes contain low concentrations of saturated
lipids

archaeal membranes contain high concentrations of saturated lipids

The tendency for atom to move from areas of high concentration
towards areas of low concentration is called:
carrier
facilited active transport diffusion
exegonic endergonic

diffusion

A cell is placed into a beaker containing a sugar solution; water
leaves the cell, the cell membrane collapses and shrinks around the
cell contents. Which statement best describes the relative solute
concentrations in the cell and in the surrounding solution?
the concentration
of solutes inside the cell is the same as the concentration in the
outside solution the concentration of solutes inside the
cell is greater than the concentration in the outside solution
the concentration of solutes inside the cells is less than the
concentration in the outside solution none of the
above

the concentration of solutes inside the cells is less than the
concentration in the outside solution

in the original Star Trek episode, "The Immunity Syndrome",
a gigantic single celled space organism destroys planets and ingests
the debris of solar systems to gain energy for it's survival. The
organism is destroyed by Mr.Spock by exploding a shuttlecraft inside
the nucleus of the space organism. Which term best describes the space organism
prokaryotic,
photosynthetic prokaryotic, heterotrophic
eukaryotic, photosynthetic eukaryotic,
heterotrophic prokaryotic, parasitic

eukaryotic, heterotrophic

Which of the following is true about enzymes?
enzymes increase the
rate of chemical reaction by lowering activation energy
barriers. enzyme function is increased if the
three-dimensional structure or conformation of an enzyme is
altered enzyme function is independent of physical and
chemical environmental factors such as pH and temperatures
enzymes are consumed in reactions and must be replaced as the
reaction proceeds

enzymes increase the rate of chemical reaction by lowering activation
energy barriers.

A patient is brough to the hospital severely dehydrated. An IV of
isotonic saline is started immediately. Why doesn't the doctor order
an IV of pure, sterile fresh water?
an IV of pure,
freshwater would cause water to leave the cells, causing them to
collapse the patient needs the nutrients available in normal
saline an IV of pure, freshwater would cause blood cells to
swell and eventually burst normal saline is more economical
than pure water pure, freshwater may be contaminated by
bacteria

an IV of pure, freshwater would cause blood cells to swell and
eventually burst

The second law of thermodynamics states that
energy is not created
or destroyed disorder in the universe constantly
increases disorder in the universe constantly
decreases energy is not created but can be destroyed
we are all water, same as it ever was

disorder in the universe constantly increases

Which of the following is (are) the major role (s) of proteins in a
biological membrane?
transporter of ions or
large molecules adhesion between adjacent cells
receptor for enzymes or other info. at the cells surface
attachment to the cytoskeleton all of the above

all of the above

The hydrolysis of sucrose to glucose and fructose is exergonic.
However, if you dissolve sucrose in water and keep the solution
overnight room temperature, there is no detectable conversion to
glucose and fructose in the morning. Why?
the change in free
energy of the reaction is neutral the activation energy is
high enough to prevent the reaction from occurring very often in the
solution the change in free energy of the reaction is
positive this is a condensation reaction this free
energy of the product is higher than the free energy of the
reactants

the activation energy is high enough to prevent the reaction from
occurring very often in the solution

facilitated diffusion is an important method for cells in obtaining
necessary molecules and removing other ones. Requirements for
facilitated diffusion include which of the following?
the carrier molecule
must be specific to the molecule that is transported. the direction
of movement is always with the concentration gradient, never against
the gradient the carrier molecule is nonspecific to the
molecule that is transported. the direction of movement is always
with the concentration gradient, never against the gradient
the carrier molecule is non specific to the molecule that is
transported. the direction of movement is always against the
concentration gradient, never with the gradient.

the carrier molecule must be specific to the molecule that is
transported. the direction of movement is always with the
concentration gradient, never against the gradient

Which of the following molecules can cross the lipid bilayer of a
membrane directly, without a transport protein or other mechanism?
oxygen
protein sucrose starch

oxygen

Glucose is a six-carbon sugar that diffuses slowly through artificial
membranes. The cells lining the small intestine, however, rapidly move
glucose from the the gut into their cytoplasm. This occurs even when
the gut concentrations of glucose are lower than the glucose
concentrations in intestinal cell cytoplasm. Using this information,
which transport mechanism described by this situation is most likely
responsible for the glucose transport in cells?
exocytosis
active transport phagocytosis simple
diffusion facilitated diffusion

active transport

An organism with a cell wall would most likely be unable to take in
materials through
facilitated
diffusion phagocytosis osmosis active
transport diffusion

phagocytosis

An enzyme is
an organic (protein)
catalyst lipid catalyst a metal ion catalyst
a detergent a phospholipid

an organic (protein) catalyst

When the size of a cell increases, the surface area/volume ratio
decreases initially and
then begins to increase remains the same
decreases increases initially and then begins to
decrease increase

decreases

Whenever energy is transformed, for example from gasoline to kinetic
energy of a speeding car, there is always an increase in
free energy of the
system entropy enthalpy the universe car
accidents free energy of the universe

entropy

Which of the following metabolic process can occur without a net
influx of energy from some other process?
APD + Pi ->
ATP+H2O 6 CO2+ 6 H20 -> C6H12O6+ 6 O2
glucose+fructose -> sucrose C6H12O6+6 O2 -> 6
CO2+6 H2O amino acids -> protein

C6H12O6+6 O2 -> 6 CO2+6 H2O

Reactants capable of interacting to form products in a chemical
reaction must first overcome a thermodynamic barrier knowns as the reactions
equilibrium point
free-energy content endothermic level
entropy activation energy

activation energy

An enzyme is __ when it loses it's native conformation and it's
biological activity; it can happen due to changes in temperature or pH.
complex
denatured specific decatalyzed

complex

Which of the following is a statement of the first law of thermodynamics?
kinetic energy is stored
energy that results from the specific arrangements of matter
the entropy of the universe is decreasing energy cannot
be created or destroyed the entropy of the universe is
constant energy cannot be transferred of transformed

energy cannot be created or destroyed

Which of these is exhibiting kinetic energy?
a rock on a mountain
ledge a person sitting on a couch while watching tv
the high-energy phosphate bonds of a molecule of ATP an
archer with a flexed bow a space station orbiting
Earth

a space station orbiting earth

Which of the following is an example of potential rather than kinetic energy?
water rushing over
Niagara Falls the muscle contractions of a person mowing
grass a molecule of glucose the flight of an insect
foraging for food light flashes emitted by a firefly

a molecule of glucose

When chemical, transport, or mechanical work is done by an organism,
what happens to the heat generated?
it is transported to
specific organs such as the brain it is used to generate
ADP from nucleotide precursors it is used to power yet more
cellular work it is used to store energy as more ATP
it is lost to the environment as increased kinetic energy in
molecules

it is lost to the environment as increased kinetic energy in molecules

Which of the following is (are) true for anabolic pathways?
they are usually highly
spontaneous chemical reactions they release energy as the
degrade polymers to monomers they do not depend on
enzymes they consume energy to increase the entropy of the
organism and it's environment they consume energy to build
up polymers from monomers

they consume energy to build up polymers from monomers

Some regions of the plasma membrane, called lipid rafts, have a
higher concentration of cholesterol molecules. At high temperatures,
these regions
are less fluid than the
surrounding membrane have higher rates of lateral diffusion
of lipids and proteins into and out of these regions are
more fluid than the surrounding membrane detach from the
plasma membrane and clog arteries are able to flip from
inside to outside

are less fluid than the surrounding membrane