Practice Midterm Review - BIO LAB
the best source of information regarding the hazards posed by any chemical and specific handling instructions is the
Safety Data Sheet (SDS)
carbohydrates like glycogen and cellulose are polymers. what is a polymer?
a chain of similar building blocks called subunits or monomers
in a catalase-controlled experiment, the negative control can be shown by
a mixture of hydrogen peroxide and water
a disinfectant is used on your work surface
after all work is complete, after any spill of microorganisms, before the beginning of laboratory procedures
the biuret test would indicate a positive result for proteins in which of the following solutions?
albumin
an increase in the concentration of substrate will result in
an increase in velocity of the reaction, until the majority of the enzyme is bound by substrate
enzyme function is optimum
at specific pH and temperature ranges
when measuring the volume of a liquid in a graduated cylinder, at which point should the measurement be taken?
at the meniscus
after they are used, reusable instruments or glassware that require sterilization should be placed in the ______
autoclave
the mechanical stage upper knob is used to move the stage
back and forth
in the metric system, gram, meter, and liter are all ________ units
basic
in the weight exercise of the metric system lab, what object/materials did you practice weighing?
beaker and salt
what does an enzyme do?
binds to substrate and converts it to product
dissection specimens and bacterial culture plates should be discarded into a __ bin when you are finished with them
biohazard
dissection specimens and bacterial culture plates should be discarded into a _________ bin when you are finished with them
biohazard
which is the most appropriate disposal for a swab used to culture your throat during lab?
biohazard bag
which of the following reagents is best suited for the detection of protein?
biuret
which color change represents a positive reaction for the presence of sugar using the Benedict's test?
blue to orange
which color change gives a positive reaction for the presence of protein using the Biuret test?
blue to purple
which of the following tests is best suited for the detection of fat and oils?
brown paper
which test is used to detect the presence of lipids?
brown paper test
starch is classified as a
carbohydrate
during the catalase lab, tubes containing which combination of enzyme and substrate will cause bubbles (product is water and oxygen) to form?
catalase + hydrogen peroxide
the base unit for temperature in the metric system is
celsius
which part of the microscope will be used first to adjust the focus when starting with the lowest power lens?
coarse focus
what is enhanced when a stain is used to make a sample, or parts of a sample, darker than the background in a slide?
contrast
which of the following is defined as the ability to distinguish an object from the background?
contrast
biuret reagent contains __________ ions which react with peptide bonds under the alkaline conditions of the reagent and produce the color change associated with the presence of proteins
copper
when utilizing the scientific method, there are two types of variables. They are
dependent and independent
if the measurement is too large or too small to be conveniently expressed by a base unit, you can use a(n) _____ unit
derived
in the metric system exercise, you measured the ________ of 3 circles
diameter
which substance in a reaction will not change in concentration as the reaction proceeds?
enzyme
when storing the microscope the stage should be left in the _________ position
fully down
which of the following should be autoclaved after working in the lab?
glass bacterial culture tubes
in the metric system, the base unit of weight is the
gram
an enzyme reduces the energy necessary to start a chemical reaction. This means the rate of reaction will
increase
an increase in enzyme or substrate concentration will
increase the amount of reaction
after focusing on an object with the low power objective lens, you are trying o bring it into focus under the 40x objective lens, but the field of view is very dark. which of the following may remedy this problem?
increase the light intensity
changing the pH will have the following effects on a catalase-controlled reaction:
increasing or decreasing the pH above or below the optimum level will decrease the acuity
which of the following reagents is best suited for the detection of starch?
iodine
which reagent is used to detect starch?
iodine
the optimum condition for an enzyme
is where it works best
why is it important to use the tare function when weighing an object placed in a beaker?
it allows you to weigh the object and disregard the beaker
which of these items can be placed in their regular trash can or recycle container?
lab notes that are no longer needed that were used during lab and do not contain dangerous chemicals or infectious organisms
emulsifiers are molecules with a polar end and a non polar end that can be used to disperse __________ into polar liquids such as water
lipids
which of the following is defined as the ability to make an object appear larger?
maginification
the lenses of a bright microscope are responsible for the __________ of the object you are viewing
magnification
which image quality factors is usually expressed in a number such as 40x?
magnification
how often can a catalase molecule be used to hydrolyze hydrogen peroxide?
many times
the base unit of length in the metric system is the
meter
which of the following units is the greatest?
meter
in the length exercise, what tool did you use to measure the circle?
metric ruler
what are the building blocks of carbohydrates?
monosaccharides
the total magnification of an image is determined by __________ the magnification power of the ocular lens and the magnification power of the objective lens used
multiplying
in which circumstance is food and/or beverage allowed in the laboratory?
never
when the enzyme is at its most active state and most of the substrate has bound the enzyme, an increase in the concentration of substrate will
not make any difference in the enzyme activity
which of the following should be done first in the event of a laboratory accident?
notify the instructor
the lens on the microscope that is primarily responsible for the magnification of the specimen is the __________ lens
objective
the lens on the microscope that is primarily responsible for the magnification of the specimen is the ___________ lens
objective
the _______ lenses further magnify the image produced by the objective lens
ocular
the _________ lenses further magnify the image produced by the objective lens
ocular
which objective lens provides the highest total magnification?
oil immersion
a given enzyme works on
one type of substrate
lab coats, gloves, face masks and goggles are all examples of
personal protective equipment (PPE)
according to the results of the pillbug experiment
pillbugs tend to prefer cornstarch over sand
when graphing your data, it is important to
place the dependent variable on the Y axis
starch, cellulose, glycogen, and polypeptides are all made from chains of many subunits, or building blocks. what is the name given to a chain composed of many subunits?
polymer
starch is a(n)
polysaccharide
in the metric system, the _______ describes the relationship of each unit to the base unit
prefix
altering the three-dimensional structure of an enzyme might
prevent the substrate from binding the enzyme's active site
the purpose of lab safety rules and protocols is to
protect everyone in the lab from injury and infection
in an enzyme-controlled reaction, a substrate is the same as
reactant
in what type of emergency situation would you utilize the lab chemical/safety shower?
removing a large volume of chemicals spilled on unprotected arms or splashed onto your face or eyes
in the weight exercise, the tare button was used to
reset the scale
increasing the __________ will allow you to tell if what appears as one s=object is really two objects very near to each other
resolution
which of the following is defined as the ability to distinguish fine detail?
resolution
the mechanical stage lower knob causes the stage to move
right and left
the objective lenses of the compound light microscope are attached to the
rotating nosepiece
in the pillbug experiment, the substance used as the control was
sand
there are two, two-sided dishes in the pillbug experiment. In one dish, you should have placed sand in both sides. In the other dish, you should have placed _________ in one side and __________ in the other side.
sand; cornstarch
what instrument did you use to weigh objects in the metric system lab?
scale
which objective lens provides the least total magnification?
scan
if leaving an object lens over the stage when storing the microscope, which objective lens should be placed over the stage?
scanning 4x
in order to come to reliable conclusions about pillbug preferences, you needed to use the
scientific method
slides, scalpels, razor blades, cover glasses, and capillary tubes are all classified as
sharps
where should glass slides, pipettes, and capillary tubes be disposed?
sharps container
when testing the temperature of catalase in the enzyme lab, why did the higher temperature affect the catalase activity?
some of the catalase enzymes were denatured
which of the following is the action on an enzyme?
speed up reactions
the positive control for the iodine test was the
starch solution
some students consume large amounts of coffee and so called energy drinks to help them stay alert when studying. You notice that many who engage in this seem to do poorly on exams. Suppose you want to investigate the relationship between caffeine consumption and exam performance. which of the following statements would be an appropriate hypothesis?
students who consume large amounts of caffeine while studying will have lower exam scores than those who consume less caffeine
increasing the concentration of substrate will increase the rate of reaction only if which of the following is a factor?
substrate is the rare limiting factor
how can you determine the optimum pH of an enzyme?
test the enzyme at different pH levels
the meniscus is
the lowest margin of water level
the liter is the metric base unit of measurement for
volume
in the pillbug experiment, your hypothesis
was related to the environment pillbugs prefer
when you are finished with the dissection tray and forceps used in dissection of a preserved specimen you should
wash them in the sink
soap should be applied to _____ hands
wet
in which situation is it most important that long hair be tied back in the laboratory?
when working with a bunsen burner
when is it crucial for you to use protective eye wear in the lab?
when working with corrosive, irritating, or infectious materials that may be a splash hazard
which color change represents a positive reaction for the presence of starch using the iodine test?
yellow to purple
when can you bring food and beverages into the lab?
you are never allowed to do so
what is the freezing point on the celsius temperature scale?
0
47.0 milligrams =
0.047 grams, 4.7 centigrams, 0.47 decigrams
assume you drink 250 mL of soda out of a 1 liter soda bottle. how many liters are left?
0.75 liters
how many grams are in 1000 milligrams?
1
how many yards does 1 meter roughly correspond to?
1
select the unit of weight that is the heaviest
1 kilogram
in the metric system, what is the meaning of "centi"?
1/100
in the metric system what is the meaning of "milli"?
1/1000
in the pillbug experiment, how many pillbugs did you need to use to get good information for the experiment?
10
the conversion between base units and derived units in the metric system are based on a factor of _____
10
how many centigrams are in a gram?
100
how many centiliters are in a liter?
100
how many centimeters are in 1000 millimeters?
100
how many centimeters are in a meter?
100
what is the boiling point on the Celsius temperature scale?
100
1,000,000 millimeters is equal to _____ meters
1000
if a specimen was being viewed using a 100x objective and a 10x ocular, what would be the total maginification?
1000x
if a specimen was being viewed using a 20x objective lens and a 10x ocular lens, what would be the total magnification?
200x
normal room temperature is 77 degrees fahrenheit. what is the normal room temp in celsius?
25
normal human body temperature on the celsius scale is approximately
37 degrees celsius
which of the following reagents is best suited for the detection of sugar?
Benedict's
imagine that you are observing an enzyme-catalyzed reaction in lab. every time you add more enzyme, the reaction rate increases proportionally until the reaction rate suddenly levels off. no other chemicals were added, and no modifications were made in the experimental setting. why do you think the reaction rate stopped increasing?
the molecules of substrate were all bound to enzyme
in the pillbug experiment, if the pillbug in the experimental chamber would have moved to the side of the chamber with sand instead of cornstarch, what would you have concluded?
the pillbugs tend to prefer sand over cornstarch
as the concentration of an enzyme increases for a given substrate
the reaction rate increases similarly
while testing an unknown solution, a student adds Benedict's reagent and watches as the content of the test tube turn green. the student then added amylase and heats the test tube. this causes the contents to turn red. which of the following conclusions could the student make?
the solution has both simple sugars and starch
when testing the temperature of catalase, what would happen if you changed the temperature using the same tube with the same catalase and hydrogen peroxide mixture?
the substrate and enzyme would bind and react before all temperatures could be tested
how does the concentration of the substrate in an enzyme-controlled chemical reaction change over time?
the substrate concentration will decrease
old lab notes, paper towels, and lens paper should be discarded into a _______ bin when you are finished with them
trash
if you wanted to test whether or not a particular pain reliever was effective in the general population, you would need to design an experiment with an experimental group and a control group. What should be the only difference between these two groups?
treatment: the experimental group should get the pain reliever, and the controls should get the placebo