AP Biology Labs

Natalie Pierre, Ugonna Ogbonna, Savannah Brown

Enzyme action: Testing Catalase Activity

Background: Enzymes speed up or increase chemical reactions by lowering the activation energy ( the energy required to start a reaction). The substrate, which are the starting materials, have many ways of displaying chemical changes such as:

★ change in color/odor, production of a gas, temperature change, precipitation and radiation.

Enzymes have the role of making it easier for substrates to form products. As a result, less energy is required for the reaction.

Enzymes are folded large protein molecules. Enzyme’s optimum condition is determined by environmental changes.

★ Purpose: In this experiment, the goal was to see the effect of pH on enzyme activity and concentration.

Enzyme Action: Testing Catalase Activity

Set Up: ❖ Three test tubes containing pH

4, 7 and 10 will have enzymes inside them.

❖ The rate of enzymes is being recorded through the Lab Quest App during the beginning and end of the reaction. The Lab Quest App will display the pressure readings for 60 seconds.

❖ The Lab Quest App will show how the enzyme’s activity was affected by comparing the beginning and end of the enzyme.

Enzyme Action: Testing Catalase Activity

Conclusion: As a result, the enzyme’s activity is highest at pH 10 and lowest at pH 4. The enzyme activity gradually increases from pH 4 to 10. ★ But at low pH values,

the protein may denature or change its structure. This could affect the enzyme’s ability to recognize a substrate or it may alter its polarity within a cell.

Enzyme Action: Testing Catalase Activity

Purpose: Observe the process of osmosis and diffusion of sucrose within a potato slice, and determine the molarity of sucrose in the solutions.

Potato Osmolarity Lab

Osmosis - movement of solvent molecules through a semipermeable membrane

solvent molecules

move into a region

of higher soluteconcentration

Diffusion - molecules intermingle

Potato Osmolarity LabSetup:● The weight of the sliced

potatoes are taken before being put into the sugar solutions.

● The sugar solutions have different molarities, but the same amount solution, in order to observe the change of the potatoes’ mass in different concentrations.

● The potatoes are then submerged into the solutions and left to set.

● The weight of the potatoes are then taken again, in order to calculate the percent change.

Results:Hypertonic - higher solute concentration and a lower water potential; water will move into the hypertonic solution through the membrane. Hypotonic - solution has a lower solute concentration and a higher water potential; water will move down its concentration gradient into the other solution. Isotonic - solutions have equal water potential.

Potato Osmolarity Lab

pGLO Gene LabPurpose: To learn about bacterial transformation. You are inserting a plasmid into the DNA of a bacteria -such as e.coli. The bacteria will produce a glow in the dark effect because it integrates this plasmid into its genetics. A certain promoter is needed to turn the expression gene on (arabinose or ARA.), which will show that it is the only culture to grow fluorescent E. coli.

➔ The setup: 4 agar plates will be labeled. The normal plates will be labeled with LB and LB/amp. The other two plates are the Transformed plates and are labeled with LB/amp and LB/amp/ara.

● LB - Food for the bacteria

● amp - kills the bacteria

● Transformed - picked up the plasmid and are resistant to ampicillin

● ara - sugar that activates the GFP

pGLO Gene Lab

(continued) In the end, the results if done correctly should be that the agar plate with LB/amp/ara is glowing.

Fast Plant Lab

Purpose:

To learn how to plant,

grow, and maintain plants. Most

importantly, to be able to

identify and quantify

phenotypes that are

conditioned by a single gene

and understand how Mendelian

traits are inherited.

● Mendelian inheritance, a child receiving a dominant allele from either parent will have the dominant form of the trait.

● Only those that received the recessive allele from both parents present with the recessive phenotype.

Fast Plant LabSetup:

Label each of the cells in the foam chamber.

Place wicks in each chamber, with the tip of the wick

halfway out. Then fill each chamber half was with

soil, press lightly to pack the soil. Place three

fertilizer pellets in each chamber. however avoid

packing the chambers with too much soil. Finish off

packing the chambers with soil and make a shallow

depression, plant 2-3 seeds into the depression and

cover it with soil. Water each chamber with a

watering pipette until the water drips from the wick.

Fast Plant LabResults:

If hairiness is inherited through the combined effect of

many different genes, it’s expected that by repeatedly

selecting the hairiest parents for next generations the number

of genes influencing hairiness in the population would

increase.

To investigate variation and selection, first record the

number of hairs for the experimental group of parent plants.

Then compare the initial data with the number of hairs

counted on the next generation (offspring).

● In this lab, we are seeing how beetles respond to their environment. One factor that could play to this is orientation. The two types of categories of orientation are taxis and kinesis. In kinesis there is undirected movement, so it is random. However, taxis is different, the movement is more complex and is the result to different kinds of stimulus

● This lab requires for the group to create their own setup and create conflicting environments for the beetle to choose as soon as it is placed in a choice-chamber.

● For example, groups may choose a wet environment versus a dry environment, or an environment with an alcohol base versus an environment with hand sanitizer, etc.

Animal Behavior

Background: Chromatography is a technique for separating and identifying pigment from plant’s leaves. The solvent moves up the paper by capillary action. As the solvent moves up the paper, pigments are carried along at a different rate. ➔ Pigments may display

chlorophyll b or a with colors ranging from blue-green and orange-red.

Chromatography Lab

Purpose: Separate the plant’s pigment and find the distance between the plant’s pigment and the solvent. Also calculate the pigment and solvent ratio.

Set Up: Two beakers will contain 2 cm of solvent in each and a piece of filter paper with extracted pigment from a plant’s leaf. Cover the beaker and wait until the solvent has traveled to 1 cm from the top of the filter paper. Measure and record the distance of the pigment.

Chromatography Lab

Results:The solubility, size of particles, and their attractiveness to the paper are all involved in the separation. The different plant pigments by chromatography and showed how to calculate Rf values and explained their importance. There are 4-5 main pigments present in plants ranging from green to yellow in color

Chromatography Lab

In corn (Zea mays), purple kernels (R) are dominant to yellow kernels (r). Cobs from the offspring of a cross between a purple plant and yellow plant were used in a lab. A student counts 329 purple and 299 yellow kernels on one cob.Calculate the chi-squared value for the null hypothesis that the purple parent was heterozygous for purple kernels. Give your answer to the nearest tenth.

FRQ Questions

EXPLANATION:A cross between a heterozygous purple corn plant (Rr) and a yellow corn plant (rr) would yield offspring that display a 1:1 ratio between purple and yellow kernels. Of the 628 kernels, it would be expected that 314 would be purple and 314 would be yellow. The chi-square value is calculated below. The acceptable answer for this question should be 1.4.

FRQ Questions