LAB TEST Flashcards
NaOH is the abbreviation for
Sodium Hydroxide
The red triangle (if on a chemical label of an actual container) will contain a number that refers to
Flammability
How many more H+ ions per Liter will there be in a solution go pH 4 compared to pH6
100
How much mass of potassium permanganate is contained
0.10 kg
When mixing cane sugar with water, the sugar disappears because it
is soluble
How many more H+ ions per liter will there be in a solution of pH3 compared to pH6
1000
Buffers are important chemicals that keep a stable ____ in organisms
pH
The yellow triangle (if on a chemical label of an actual container ) will contain a number that refers to
Instability reactivity
How many more H+ ions per liter will there be in a solution of pH 3 compared to pH 7
10,000
True or False Enzymes can be considered activists which bring molecules together
False
Your stomach has a pH of 2. Its contents are
Acidic
When enzymes lose their 3d shape they lose the ability to function. this change of shape that leads to loss of function is called
Denaturation
True or false
Catalase is found only in animal cells
False
Catalase break down which toxic substance in cells
Hydrogen Peroxide
Which of the following are the products of the reaction catalyzed by catalase
water and oxygen
in the catalase experiment, what do bubbles represent
Breakdown of hydrogen peroxide into oxygen gas
after boiling the test tubes, what is the next step before testing for catalase activity
allow the test tubes to cool
About how much hydrogen peroxide should be added to each test tube when testing for catalase activity
5ml
why is it so important to boil some of the tissues (liver or potato) in this experiment
to observe how cooking changes the tissue color
what type of microscope will be used In this lab
Compound light microscope
What is the total magnification when using a 10x ocular lens and a 40x objective lens?
400x
What does the diaphragm lever control?
The light passing through the specimen
Why should you avoid using the coarse focus knob when the high-power objective is in place?
It could hit (and maybe break) the slide or lens
When increasing the magnification, what typically happens to the field of view?
It decreases
What will happen to the resolution of the image when the magnification is increased?
Resolution will increase
Which term describes the range of depth that can be in focus at one time?
Depth of field
What should you first try if you have turned the coarse adjustment knob all of the way and the image is not in focus?
Return the coarse focus knob to the starting position and try again slowly
How should you carry the microscope?
With both hands: one on the arm and one on the base
Which of the following lenses provides the smallest depth of field?
High-power objective
What is the main purpose of preparing a bacterial smear?
To adhere the cells to the slide so they are not washed off during staining
Why is it important to prepare a thin smear?
To visualize individual cells and their arrangement
What is the primary goal of heat-fixing the smear?
To kill and adhere the bacteria to the slide
What is a potential consequence of using too much heat when fixing a slide?
The slide could shatter.
How should the inoculating loop be treated before touching the bacterial culture?
Flame the loop until it is red-hot and allow it to cool
What is the main purpose of the Gram staining technique?
To differentiate bacteria into two groups based on cell wall composition
Gram-negative bacteria appear what color after Gram staining?
Red/Pink
What is the primary difference between Gram-positive and Gram-negative bacteria in terms of cell wall structure?
Gram-positive bacteria have a thicker peptidoglycan layer
Gram-positive bacteria appear what color after staining?
purple
In the Gram staining process, what happens if you skip the iodine step?
Both types of bacteria will appear red
What shape is DNA?
Double helix
What are the three components of a nucleotide?
Base, sugar, and phosphate group
What is DNA extraction?
The process by which DNA is separated from proteins, membranes, and other cellular material contained in the cell from which it is recovered.
True or False: Never lay a pipette with a sample in it on its side. Chamber contamination can result.
True
Which precipitation method is used during this experiment?
Salt precipitation
Fill in the blank: ______ will be the basis of almost all the experimental work that you’ll do. So it is important to develop good technique in order to get precise and accurate results.
Pipetting
What does the sequence of bases in DNA determine?
The information available for building and maintaining an organism
How should you dispense the sample out of your micropipette?
Depress the push button to the first stop, and then depress to the second stop
