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