BIOL 111 Lab

Which of the following would not be expected to have an effect on the activity of ß-galactosidase?

*BSA concentration *Absorbance

Which of the following are not allowed in lab?

*Drinking water (or anything else) *Chewing gum *Applying cosmetics (including lip balm) *Eating food

Which statement directly describes, in general, a blank used to 0 (zero) the spectrophotometer?

The blank includes everything in your experimental samples except what you want to measure.

In spectrophotometry, _____ is the fraction of light that passes through the sample while _____ is the fraction of light that does not pass through the sample.

transmittance absorbance

Match the following terms with their definitions (answers may be used more than once or not at al) Accuracy Precision Standard curve Molar weight

*Accuracy: How close a result is to the correct/standard value *Precision: How variable a measurement is (for example, if you are measuring the same value on three occasions) *Standard curve: A graph where properties of known samples are plotted *Molar weight: A measure of mass

Match the following terms and definitions (answers may be used more than once or not at all). Aliquot Micropipette Spectrophotometer Cuvette

*Aliquot: A portion of something *Micropipette: An instrument used to measure and deliver very small values with high accuracy and precision *Spectrophotometer: An instrument for measuring the amount of light that passes/does notepads through a sample *Cuvette: The tubes which hold small inside spectrophotometer

Match the following experiment components to their role in the experiment. Dry beans Soaked beans Respirometer Water bath

*Dry beans = control *Soaked beans = experimental sample *Respirometer = a tool to measure the consumption of gas *Water bath = keeps samples at a constant temperature

While experiments are being conducted in the lab, which of the following must be worn?

*Goggles *Gloves

Which of the following statements about PPE for your eyes are TRUE regarding the BIOL 111 lab?

*Goggles for BIOL 111 must seal completely around your eyes and cannot have any uncovered vents. *Goggles must be worn when handling any chemicals.

Which of these statements are true about micropipettors?

*Have a specific range of volumes which each size micropipette can handle. *The first stop is used to draw the desired volume into the tip. *Dispense very small and precise volumes of fluid. *The second stop is used dispense fluid from the tip.

Which of the following statements are true regarding BIOL 111 labs?

*Never eat in lab (includes candy and chewing gum). *Gloves are required for some experiments.

Which of the following are true about spectrophotometers?

*Works by shining light of a specific wavelength through the sample. *Can measure how much light passes through the sample (transmittance). *Can measure how much light is absorbed by a solution.

Which of the following statements are true regarding footwear in BIOL 111 labs?

*You may lose TA points if you do not arrive wearing close-toed shoes in lab. *Shoes must cover your toes and a majority of your foot.

Complete the sentences by matching. *Shoes must be *clothing and jewelry *long hair *to avoid transferring chemicals to sensitive areas

*shoes must be - close-toed and cover most of your foot *clothing and jewelry - should not dangle *long hair - should be tied back *to avoid transferring chemicals to sensitive areas - avoid touching your face and eyes in lab.

Match the following terms based on this week's experiments: *The enzyme is * The substrate is *The product which you will measure via spectrophotometry is *The colorless product is

*ß-galactosidase *ONPG (ortho-nitrophenyl-ß-galactoside) *ortho-nitrophenol *galactose

When creating a serial dilution from 1/10 to 1/1000, the first dilution will be _____ part sample and _____ parts diluent (what you dilute the sample in). The second dilution will be one part _____ and nine parts _____. The final dilution will be one part _____ and nine parts diluent.

1 (one) 9 (nine) 1/10 dilution diluent 1/100 dilution

Place the following steps of aerobic respiration in order. Electron transport chain Glycolysis Krebs/citric acid cycle Oxidation of pyruvate

1. Glycolysis 2. Oxidation of pyruvate 3. Krebs/citric acid cycle 4. Electron transport chain

Place the steps of measuring a sample's absorbance in order from 1-5.

1.Set wavelength on spectrophotometer. 2. Wipe the cuvette containing the blank and insert it into the spectrophotometer. 3. Adjust absorbance/transmittance dials till the readings are 0. (Then remove cuvette.) 4. Wipe the cuvette containing the sample and insert it into the spectrophotometer. 5. Record absorbance reading.

You have a stock solution that is 110 mg/mL and you need 10 mL of a working solution that is 68 mg/mL. What volume of stock solution will you need to dilute to have 10 mL of working solution at the above concentration? State your answer to two decimals and do not include units in your answer.

6.18 (68 mg/mL / 110mg/mL = 0.618 * 10 mL = 6.18 mL)

Select the appropriate pipette to use for each of the following volumes. 874 microliters 57 microliters 340 microliters 15 microliters

874 microliters = P1000 57 microliters = P200 340 microliters = P1000 15 microliters = P20

If you have a sugar with a molecular weight of 309 g/mol, how many grams would you need to add to 127 mL of water to create a 248 mM solution?

9.73 (0.248 * 0.127 = 0.031496 * 309 = 9.73)

Which of the following statements about cellular respiration are TRUE?

Anaerobic respiration produces fewer ATP than aerobic respiration.

Which of these statements are good examples of following lab safety protocols?

Asking the TA if you can step outside to get a drink of water.

For the experiment measuring concentrations of BSA using spectrophotometry, the blank will include which of the following?

Bradford Reagent NaCl

Which of these reagents binds to protein to create a color change that you can measure?

Bradford reagent

What is the purpose of lysis buffer in the experimental reactions?

Breaks open cells by disrupting the cell membrane.

When you arrive at lab, which of the following do you need to be wearing?

Close-toed shoes

Which bacteria is the source of the enzyme used in this week's experiments?

Escherichia coli

During the process of glycolysis, the potential chemical energy released by the breakdown of glucose is stored as

NADH and ATP

Which microorganism will be used in the fermentation experiments?

Yeast

In general, a slight increase in temperature will [a] the rate of cellular respiration. This is most directly due to [b] increasing in [c] conditions.

[a] = accelerate [b] = enzyme activity [c] = warmer

[a] is an overarching term that includes all processes living organisms use to produce [b].

[a] = cellular respiration [b] = ATP

This week's experiment will examine cellular respiration by measuring [x] consumption. Meanwhile, any [y] produced by the cells will react with KOH (potassium hydroxide) to form non-gaseous molecules.

[x] = O2 (oxygen) [y] = CO2 (carbon dioxide)

Experiment 1 this week will examine the effect which substrate [a] has on enzyme [b]. Experiment 2 will instead vary [c] concentration. Both experiments will utilize the [d] to measure changes in [e].

a. concentration b. activity c. spectrophotometer d. absorbance

Enzymes bind [a], which fit into a spot called the [b]. The enzyme then [c] a biochemical reaction, [d] the rate at which the reaction takes place.

a. substrates b. active site c. catalyzes d. speeding up

Ortho-nitrophenol production can be measured with a spectrophotometer due to which of the following characteristics?

color

The _____ is used when puling the desired volume into the tip. The _____ is used to dispense the full volume out of the tip.

first stop second stop