Biology Lab Exam #1

To find absorbance

(A420/time (sec))*1000 Time sec ex: 25*60+ sec

Match the following terms based on this week's experiments: Question Selected Match 1. The enzyme is 2. The substrate is 3. The product which you will measure via spectrophotometry is 4. The colorless product is

1. ORTHO 2. 3. ONPG (ortho-nitrophenyl B- galactoside) 4. GALACTOSE

Select the appropriate pipette to use for each of the following volumes. 1. 874 µL 2. 57 µL 3. 340 µL 4. 15 µL

1. P1000 2. P200 3. P1000 4. P20

1. Be able to calculate oxygen consumed over time 2. Be able to calculate oxygen consumed per hour

1. Take the first value from the last value 2. Take the value that you got and create a proportion table

Match the following experiment components to their role in the experiment. 1. Dry beans 2. soaked beans 3. Respirometer 4. Water bath

1. control 2. experimental sample 3. tool to measure the consumption of gas 4. keeps samples at a constant temperature

If you have a sugar with a molecular weight of 190 g/mol, how many grams would you need to add to 115 mL of water to create a 78 mM solution?

1.7043

Which milk would have the most or least color change to blue?

1:10 dilution because there is more in there other than the others

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

1:10 means 1 initial solution & 9 parts H2O 1:100 means 1 initial solution to 99 pure water 1:1000 means 1 initial solution to 999 pure water

You have a stock solution that is 116 mg/mL and you need 10 mL of a working solution that is 56 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.

4.83

Molar Weight

A measure of mass

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

A portion of a larger whole

What happens to enzyme activity when you have low, medium, or high substrate concentration?

A reaction will increase or decrease depending on whatever the substrates are doing

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

Absorbance BSA concentration

Which of the following statements about cellular respiration are TRUE?

Anaerobic respiration produces fewer ATP than aerobic respiration.

How do we know that the spinach disk were doing photosynthesis?

As photosynthesis proceeds, oxygen accumulates in the air spaces of the spongy mesophyll. The leaf becomes buoyant and floats. While this is going on, the leaf is also carrying out cellular respiration.

At what point will a reaction plateau? What does it mean when a reaction is saturated?

At high substrate concentration, the reaction rate reaches a plateau as the enzyme active sites become saturated with substrate (ES complex), and no free enzyme to bind the added substrate.

What lights are bets or worst for photosynthesis?

Blue light works the best Green light works the least

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 happens in a lysis reaction?

Breaking down of a cell

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

Breaks open cells by disrupting the cell membrane.

What calculation is needed to make stock solution?

C1V1=C2V2

Which are required for photosynthesis to occur?

Carbon dioxide Sunlight Water

Which microorganism will be used in this week's experiments?

Chlamydomonas

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

Color

Which of the following materials from this week's lab require special safety consideration (be more careful with them than normal!)?

DCMU Sodium azide

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.

Enzymes bind substrates, which fit into a spot called the active site. The enzyme then catalyzes a biochemical reaction, speeding up the rate at which the reaction takes place.

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

Escherichia coli

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].

Experiment 1 this week will examine the effect which substrate concentration has on enzyme activity. Experiment 2 will instead vary enzyme concentration. Both experiments will utilize the spectrophotometer to measure changes in absorbance.

What is the difference between lactose, galactose, and glucose? Which does E. Coli prefer?

Galactose is a single molecular form of sugar that's found in milk Lactose is what forms when galactose combines with glucose and becomes a disaccharide E. Coli prefers glucose

Place the movement of electrons in order through the light reactions of photosynthesis, from the molecule that is split to generate them to the molecule that will act as the final electron acceptor.

H20 photosystem 2 electron transport chain Photosystem 1 NADP+

In spectrophotometry, [1] is the fraction of light that passes through the sample while [2] is the fraction of light that does not pass through the sample.

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

When do yeast respire and when do they undergo fermentation?

In the presence of oxygen, yeast undergo aerobic respiration and convert carbohydrates (sugar source) into carbon dioxide and water. In the absence of oxygen, yeasts undergo fermentation and convert carbohydrates into carbon dioxide

Why is chlorophyll a important?

It's directly involved in the conversion of light energy to chemical energy

What light colors were the controls in the photosynthesis lab? Which was the positive and negative?

Light & dark the positive was the light the dark was the negative

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

NADH and ATP

Photosynthesis uses, releases, and produces different molecules. Use/release/production of which of the following causes the floating spinach disks measured in the photosynthesis and wavelength experiment?

O2

How are the processes of photosynthesis and cellular respiration interconnected?

Photosynthesis makes the glucose that is used in cellular respiration to make ATP. The glucose is then turned back into carbon dioxide, which is used in photosynthesis.

Photosynthesis results in the production of [b], which is the primary energy source in cells. The byproduct of photosynthesis is [a].

Photosynthesis results in the production of glucose, which is the primary energy source in cells. The byproduct of photosynthesis is oxygen.

Why did we need to remove air trapped in the spinach?

So that the spinach did not float and it lost all of its oxygen

What are the two poisons in the chalmydomyas experiment?

Sodium azide DCMU

Which of the following statements about the Chlamydomonas experiment are TRUE?

Sodium azide is a metabolic poison inhibits the mitochondrial electron transport chain. Movement of Chlamydomonas will be used to test the effect of metabolic poisons.

How is sodium azide different from DCMU

Sodium azide is different from DCMU because with sodium azide it inhibits the mitochondrial electron transport chain and stops it. The DCMU It blocks the plastoquinone binding site of photosystem II, disallowing the electron flow from photosystem II to plastoquinone

In the wavelength and photosynthesis experiment, what is the purpose of the beaker left in the dark?

The beaker in the dark is a control because it has all the experiment components but photosynthesis should not occur without light.

Which statement correctly 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.

The [x] is used when pulling the desired volume into the tip. The [y] is used to dispense the full volume out of the tip.

The first stop is used when pulling the desired volume into the tip. The second stop is used to dispense the full volume out of the tip.

What was sodium bicarbonate used for in the spinach disk experiment?

The function of the sodium bicarbonate in this experiment, was providing carbon dioxide for photosynthesis to occur.

How does cold, room, and hot temperatures affect the rate of cellular respiration?

The increase in temperature enhances the rate of cellular respiration. ... It means reactions speed up and rate of cellular respiration increases. When temperature decreases, in order to conserve energy, cellular processes slow.

Which poison affected the chalmydomas movement? Why does this poison affect it better than the other?

The poison that affected the chalmydomas movement the beat was the DCMU. This poison worked better because it is not a toxic material used to stop oxygen

What was the purpose of the garbanzo bean experiment?

The purpose of this lab was to determine the amount of oxygen consumed by different types of beans

What happens to product formation when you have low medium or high enzyme concentration?

The reaction will increase or decrease along with whatever the enzymes are doing

What's the difference between stock solution and working solution?

The stock solution is the DMSO solution in which your primers are shipped. Working solutions are any dilutions that are made using the stock, generally into aqueous solution.

Why do we use a standard curve?

They are used to determine the value of an unknown quantity from one that is more easily measured

Why is it important to equilibriate your beans to the correct experimental temperature?

To make sure that all of the material is collected so the experiment is not ruined

What is sodium carbonate used for?

To stop the reaction of ONPG after it turned the color of a post note

How did we use the color of ONPG to measure our results in the enzyme experiment?

We put it in a spectrophotometer and used the color according to the wavelength

Select the wavelengths that will be tested for their effect on photosynthesis.

White light Green light Red light Blue light

How was the rate of cellular respiration measured in the third lab?

With a respirometer

Which microorganism will be used in the fermentation experiments?

Yeast

How do you pick which dilution to use? How is this important?

You pick it off of deciding how much portion you need to add to what you already have like what parts to what

Standard Curve

a graph where properties of known samples are plotted

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. increase b. molecules c. kinetic

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.

cellular respiration by measuring O2 (oxygen) consumption. Meanwhile, any CO2 (carbon dioxide) produced by the cells will react with KOH (potassium hydroxide) to form non-gaseous molecules.

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

cellular respiration is an overarching term that includes all processes living organisms use to produce ATP.

Why is chlorophyll b important?

central role is to expand the absorption spectrum of organisms.

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)

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

instrument to measure and deliver very small volumes with high accuracy and precision

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

measure the amount of light that passes/ does not pass through a same

What are serial dilutions?

method of obtaining a dilute concentration from a highly concentrated one

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

the tubes which hold sample inside the spectrophotometer

How does potassium hydroxide participate in the cellular respiration experiment?

was used to alter the equilibrium. KOH removed the carbon dioxide and oxygen was used by cellular respiration thus decreasing the gas in the respirometer.

Why does the milk need to be diluted?

with proper amount of water is the common way to reduce the level of fats in milk...