biology lab mt

Hydrogen peroxide is broken down to produce water and oxygen with the help of the enzyme catalase. Which of the following can be measured to determine the enzymatic activity? Select all that apply.

how much hydrogen peroxide is used how much water is produced how much oxygen is produced

Which of the following are phases in LearnSmart Labs' 4-phase model of the scientific method? Select all that apply

hypothesis experiment

Which of the following unexpected results could occur if you used the catalase before it had a chance to reach your experimental temperature? Select all that apply.

in the experiment with the cooled enzyme, you would get a higher bubble column that expected in the experiment with the over heated enzyme, you would get a higher bubble column than expected

Inconsistent ratios between sample solutions and reagent result in

inconsistent test results

An enzyme reduces the energy necessary to start a chemical reaction. This means that the rate of the reaction will __.

increase

Which topics belong in a scientific paper? Select all that apply.

introduction results procedure

In the enzyme experiment, what was the purpose of preparing a tube with water and hydrogen peroxide? Correct Answer it is a negative control

it is a negative control

Suppose two groups of people are participating in the testing of a new drug. One group is given a placebo like a sugar pill. What is the roll of the placebo group.

it is the control group

How does the pillbug react when confronted with a noxious substance?

it moves away

Which of the following is the major difference between proteins, polypeptides and peptides?

length

What do you do in the LabSmart's hypothesis phase? Select all that apply.

make a strategy for the experiment formulate the hypothesis

When measuring volume, which system of measurement is most accurate?

metric system

Which of the following approaches to the study of organisms enables direct viewing of the cells?

microscopic

Increasing the concentration of enzyme results in __ substrate interacting with the enzyme per unit volume.

more

Which of the following could be a potential danger to a student during a dissection? Select all that apply.

mouse scapel

What parts of the microscope move? Select all that apply

nose-piece focus know stage

Which of the following are found in both plant and animal cells?

nuclei

Personal items on the lab bench should be limited to (select all that apply)

pen/pencil lab manual

Phospholipids have a similar structure to fats except they contain a __ group in place of the thrid fatty acid.

phosphate

A positive reaction for the presence of protein using the Biuret test would be __ in color.

purple

Which of the following colors indicates a positive reaction for the presence of reducing sugar using Benedict's test?

red

In which type of emergency would you utilize the safety shower?

removing a large volume of chemicals from your body

What do you do in each of the four phases

report- document your results and compose a report experiment-carry out the stradegy and make measurements analysis-draw graphs; evaluate hypothesis hypothesis-

What distinguishes scientific results from emotional or religious claims?

scientific results have undergone systematic testing

How should a subject be chosen to be part of a control group or an experimental group?

selection should be random

Slides, scalpels, razor blades, cover glasses and capillary tubes are classified as

sharps

Which of the following techniques can be used to view living specimens? Select all that apply.

simple stain wet mount

A dense object will be characterized by which of the following?

small volume and high weight

How do pillbugs detect the presence of food?

smell

Suppose your hypothesis is "braking distance grows linearly with speed". What is the independent variable?

speed

Which of the following techniques is used to increase the contrast of a microscope sample so that cellular components and details can be observed?

staining

At very high temperatures enzymes can exhibit less activity or none at all. Which of the following could explain this? Select all that apply.

the active site has changed shape so that the substrate can not fit the enzyme has denatured and cannot interact with the substrate

Increasing the concentration of hydrogen peroxide will increase the reaction rate of catalase if which of the following is true?

the concentration of substrate is limiting the rate

In the enzyme experiment, how did you know the reaction was occurring?

the production of oxygen caused bubbling in the test tube

What is more important, to choose the correct hypothesis or to test the hypothesis well?

the right test is more important

Which of the following are functions of proteins? Select all that apply.

they act as catalysts they can be structural they can play a role in the immune system they can be for signaling

Prior to the cheek epithelial smear, what should be sanitized?

toothpick

At higher temperatures, molecules move more rapidly

true

Changing the pH of an enzyme reaction can alter how rapidly the product is formed.

true

Not boiling the Benedict's test long enough can result in a false negative.

true

When measuring the length of irregular objects like bones, which of the following is important to do?

use a straight edge or caliper to line up the ends of the object along a ruler

Besides rubbing your hands together, what step is a part of thorough hand washing?

using a stick or brush to clean under nails

What should be removed before washing your hands? Select all that apply

watch gloves hand or wrist jewelry

In the chemical composition experiment, the negative control tube contained

water

Soap should always be applied to __ hands

wet

The __ __ preparation allows one to observe the behavior and movement of microorganisms with a light microscope.

wet mount

In which of the following situations would you use the fume hood?

working with hazardous chemicals

After viewing a slide under oil immersion, what could happen if you rotated the nosepiece the wrong direction before removing the slide?

you could drag the 40x objective lens through the oil making it dirty

Which of the following is the correct meaning of the prefix "milli"?

1/1000

In the brown paper bag test for fats, what is the minimun amount of drying time that must pass before determining the test results?

15 minutes

1 cup corresponds to approximately __ mL

240

Room temperature water is often described as tepid or lukewarm. A Celsius thermometer placed in room temperature water should record approximately which temperature?

25 degrees C

2584 centimeters corresponds to __ meters

25.84

How many feet does 1 meter roughly correspond to?

3

Three test tubes are set in a rack. They contain the following: Tube 1: 4 cm of hydrogen peroxide & 3 cm catalase Tube 2: 4 cm of hydrogen peroxide & 5 cm catalase Tube 3: 4 cm of hydrogen peroxide & 7 cm catalase In which tube will you see the highest column of bubbles?

3

1 ounce corresponds to approximately __

30 ml

At what temperature on the Fahrenheit scale does water freeze?

32 degrees F

Normal body temperature when taken orally is about 98.6 degrees Fahrenheit. If you used a Celsius thermometer, what would the reading be?

37 degrees C

Which lens could get dirty with oil if you move the revolving nosepiece in the wrong direction after viewing under oil immersion?

40x

58.6 centimeters corresponds to __ millimeters

586

How many pairs of legs does a pillbug have?

7

What are the advantages of using a wet mount? Select all that apply

The specimen can be viewed as living cells the motility of a specimen can be viewed under the microscope

In the enzyme experiment, what were the reasons to measure the height of the bubble column exactly 20 seconds after combining the catalase with the hydrogen peroxide? Select all that apply.

at shorter or longer times, the differences in enzyme concentration might not correlate to bubble height the timing must be standardized between the tubes

Reusable dissection instruments or glass tube that requires sterilization should be placed in the

autoclave

A positive reaction for the iodine test for starch is indicated by a(n) __ color.

black

Which of the follow shoes would be acceptable in the lab? Select all that apply.

boots sneakers

In the example where the hypothesis is "The braking distance grows linearly with the speed", what should go on the y-axis?

braking distance

A wet mount is time consuming.

false

All laboratory chemicals can be poured down the sink.

false

Due to their small size, all plant and animal cells must be visualized using electron microscopy.

false

Hand washing is not necessary if gloves have been worn.

false

To determine the activity of an enzyme, you can compare the concentration of the enzyme before and after the chemical reaction.

false

When the enzyme catalase is mixed with the substrate water, oxygen bubbles are produced.

false

Which best describes the pillbug's organ of respiration?

gills

Proteins are composes of building blocks called (two words)

amino acids

What should your hypothesis represent?

an explanation to a problem or observation

When you measure the diameter of a circle, which length are you measuring?

along a line dividing the circle in half at its widest poinit

Why is it important to use the tare function when weighing an object on paper or in a beaker?

It allows you to get the weight of the object and not the container

John places one drop of a sample solution onto a piece of brown paper. After a period of two minutes, he observes that the spot remains on the paper and concludes the sample contains oil. Has John drawn a valid conclusion? Why?

No. Water and other non-lipid substances may take up to 15 minutes to evaporate from the paper.

Indicate the correct order of steps as you bring an object into focus under high power

Step 1 Place slide on stage and secure with clip Step 2 Center the specimen over light source Step 3 focus specimen on low power using coarse adjustment Step 4 focus specimen with fine focus on low power to sharpen image Step 5 rotate to high power lens Step 6 readjust using fine focus while on high power to produce sharp image

Match the steps of performing a cheek cell smear.

Step 1 gently scrap inside of cheek Step 2 place scrapings on clean, dry slide Step 3 add one drop of stain Step 4 cover with coverslip

When should hands be washed? Select all that apply.

after the lab exercise prior to the lab exercise anytime hands are potentially contaminated

Which of the following structures is present in animal cells but not plant cells?

centrioles

The functions of lipids include which of the following? Select all that apply.

construction of membranes storage of energy

Which of the following does a lab coat protect against? Select all that apply.

corrosive chemicals infectious microbes

Which of the following can be properly disposed of in the biohazard bag? Select all that apply.

dead lab animals petri dish with bacterial culture discarded dissection tissue

If catalase is present in excess, reducing the amount of hydrogen peroxide in the reaction mix will __ the reaction rate

decrease

The weight to volume ratio of a substance describes which physical property?

density

The dispersal of fat molecules in water is called

emulsion

Proteins that speed up biochemical reactions are called _

enzymes