BIO 1611: Lab Practical Final
Most students found ONP production in tubes incubated at 100 degrees C. Does lactase function at this temperature? Explain
- Lactase would be completely DENATURED - The extreme temeperature increased the spontaneous breakdown of ONPG into ONP
Why was it important to use an extremely high concentration of ONPG for experiment 1 of Lab 3 (Enzyme Activity)?
- Only 1 variable can be tested at a time - the experimental variable is Enzyme Concentration, therefore substrate concentration must be kept high enough so that the rate of the rxn is independent of the substrate concentration
The active site of an enzyme is:
- fragile and dynamic - complementary in shape and chemistry - the catalytically active region of an enzyme
How do you calculate the diameter of a single cell, given the field diameter of the objective used?
If you know the field diameter for an objective, you can estimate how many cells will fit across the diameter then divide the diameter by the estimated number of cells
Osmosis refers specifically to what?
diffusion of water molecules across a membrane
How could you decrease the distance molecules migrate in an electrophoresis experiment?
increasing the concentration of agarose in the gel
In Lab 7, you transformed bacteria taken from ____________
jellyfish
The migration rate of DNA fragments is directly related to their________
length
Bacteria that have the _______ _________ will survive in the presence of the antibiotic penicillin
pGLO plasmid
What was your experimental variable for Lab 5?
pH
Bacteria produce small circular molecules of DNA called ___________
plasmids
Two dye molecules equal in size and charge may have different migration rates through an agarose gel because of their difference in ________
shape
What was the most likely role of PARP-1 in WBCs?
since cladribine is effective at slowing cell reproduction, PARP-1 in WBCs was most likely used to inhibit cell production
Gel electrophoresis is a powerful and widely used analytical method that separates molecules on the basis of their _____, _____, ______
size, charge, shape
List four variables you controlled in Lab 5?
Substrate concentration Enzyme concentration Phosphate buffer Time
Why is ampicillin added to plates A and B?
To kill all cells that haven't been transformed
(T/F) The transfer of the human insulin gene into bacteria is called "genetic transformation"
True
Gel electrophoresis is useful for what?
determining paternity, diagnosing genetic diseases, providing evidence in criminal cases
What was the purpose of Study 1? (Lab 1)
effect of cladribine and subiolsamide on rate of cell reproduction
What was the purpose of Study 2? (Lab 1)
effect of cladribine and subiolsamide on the concentrations of 5 cellular proteins
Why is HEAT shock necessary?
Heat shock provides the stress needed to get the bacteria to take up materials from their surroundings
In Lab 3 (Enzyme action), how was the formation of product detected during that lab?
colorimetric measurement using a spectrophotometer
When is a pie chart appropriate?
comparing part to whole (indicate percents)
The Osmotic Pressure of a solution is proportional to what?
concentration of the solution, temperature, gas constant
What does it mean to say that a plant cell is "isotonic" to its surrounding solution?
cytosol has same osmolarity as the surrounding fluids
What is the natural role of lactase in mammals?
hydrolysis of a disaccharide
In Lab 2, you measured the movement of _________ across dialysis tubing
water
When is a bar graph appropriate?
when independent variables are discrete (ex. cell length and species)
After bacteria are spread on agar plates, each cell will multiply to form a ________, which appears as a dome of cells on the agar surface
colony
What is the correct order in preparing the blank for the enzyme lab?
Enzyme --> Na2CO3 --> ONPG
In preparation of their blank a pair of students accidentally combined the enzyme and substrate before adding NaCO3. How would this mistake affect their subsequent absorbance readings?
ONP would accumulate in their blank and therefore their readings would be inaccurately low
Lactase catalyzes the conversion of what?
ONPG into galactose and ONP Lactose into galactose and glucose
Why don't the cells in Plate A fluoresce in Lab 7?
Arabinose is required to turn on the GFP gene and it is not present in the growth media
What is true about enzymes? A. They increase the energy of activation of chemical rxns B. They accelerate and steer chemical processes in organisms C. They consist of monosaccharides joined together to form polysaccharides
B. They accelerate and steer chemical processes in organisms
In the electrophoresis experiment of Lab 6, what type of molecules were separated?
dye
What was the purpose of Study 3? (Lab 1)
effect of cladribine and subiolsamide on the health of neuronal cells