Transcript AP Biology Labs

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.
Enzyme Action: Testing Catalase Activity
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.
Potato Osmolarity Lab
Purpose: Observe the process of
osmosis and diffusion of sucrose
within a potato slice, and
determine the molarity of sucrose
in the solutions.
Diffusion - molecules
intermingle
Osmosis - movement of
solvent molecules through a
semipermeable membrane
solvent
molecules
move into a region
of higher solute
concentration
Potato Osmolarity Lab
Setup:
● 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.
Potato Osmolarity Lab
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.
pGLO Gene Lab
Purpose: 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
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
●
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.
importantly, to be able to
identify and quantify phenotypes
that are conditioned by a single
gene and understand how
Mendelian traits are inherited.
Fast Plant Lab
Setup:
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 Lab
Results:
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).
Animal Behavior
● 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 choicechamber.
● 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.
Chromatography Lab
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
FRQ Questions
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.