IA Write Up Due - Thursday May 24

On Thursday May 24th, your data collection and processing / conclusion and evaluation components of the IA are due.  You must bring a printed copy of this to class.  Be sure to look at the information on www.i-biology.net

Leaf Disk Assay

If you've been wondering what we've been doing since the last post, we've still been working on the leaf disk assay.  Below is the student progress chart.  Each "X" represents one trial and each trial can take between 15 and 25 minutes to run, depending on how long it takes the leaf disks to sink.

The 0% solution will be just the soap and water solution, without any sodium bicarbonate.  This serves as the control.  Remember to also record qualitative observations!!

Floating Leaf Disk Assay

In addition to the procedure in the post below, here are some notes:

Add 2.5g of Sodium Bicarbonate (not 3cm)

The independent variable you decided on is to vary the concentration of sodium bicarbonate in solution:

2% (0.15g)
4%
6%
8%
1%

To ensure the 'freshness' of the leaves, we will use ivy from the wall behind the science labs.

Design IA #2 - Enzymes

Below is a table with those of you who know what enzyme, IV, DV and type of measurement you will be using for your IA.   If over the weekend you decided to change your design, please let me know.

Name	Enzyme	I.V.	D.V.	Measured with
Gabri	Lactase	Δ pH	Δ temp.	Temp. probe
Sebastian	Salivary amylase	Δ pH	Time of Rxn
Aleksa	Peroxidase	Δ pH	Δ temp	Temp probe
Sofia	Pepsin	Δ pH	Δ temp	Temp probe
Csilla	Amylase	[enzyme]	Δ temp	Temp probe
Thais	Lactase
Lud	Salivary Amylase	[enzyme]	Δ in [sugar]	Glucose meter
Zoe	Pectinase	Δ pH	Volume of juice	cm3
Dani	Lactase	Δ pH	Δ temp.	Temp. probe

If your name is not listed or if your information is incomplete, get going!

Remember to have a sample data table in your design as well as a place to record qualitative observations / data as well.

Enzymes Design IA

On May 4th you will have a Design IA due.  This is only the design component, you will NOT need to actually do this IA.  Since you don't need to actually conduct this investigation, a shortage of equipment will not be a limiting factor for your experiment.

You will design an experiment that specifically addresses this statement:

Investigate a factor that may effect enzyme activity.

Go here to see a list of common enzymes in the human body.  Recall the factors that affect enzyme activity (temperature, pH, substrate concentration).  You will need to research your enzyme and include appropriate background information.  Make sure you cite these sources!!!!

The blue and green book reminds you that time should NEVER be an independent variable (pg. 5).

Your experiment can NOT be the same as anyone else's in the course.

E period - you will have class time on Monday and Wednesday to work on this.

H period - you will have class time on Tuesday and Wednesday to work on this.

Lastly, please, please, please remember that this is one aspect of your IB grade that YOU have complete control over!

Internal Assessment Write Up

Today we discussed what you need to do to earn "complete" scores for your Internal Assessment.

As you write your IA make sure that you are referencing the IB Biology Guide for Internal Assessment.

Below are a list of links that will help you with your IA.

Data Collection & Processing from I-Biology

Conclusion & Evaluation from I-Biology

IB Bio Excel Stat Book - download an excel workbook with a flow chart to help you determine how to process your data.

IBO Website with samples of Complete & Partial graphs and tables. - see what it takes to have earn a complete.  The difference is in the details.

Errors for consideration in your conclusion & evaluation

How to determine a confidence interval for your data

IA practice

Today students had the opportunity to practice their design before officially beginning their IA next week.    Many of you realized that you needed to change your procedure, use smaller quantities or just by chance chose the optimal time for your experiment to run.

Below are link to the manuals for the Vernier Probes you might have chosen for this experiment.  These manuals also include the actual uncertainties for the equipment as established by Vernier.

Gas Pressure sensor
pH sensor
Temperature sensor

For Monday (or Tuesday) set a goal for your self.  You have four hours of class time to complete this experiment, so manage your time wisely.

Enzymes HL Topic 7 and SL Option C

Today (or tomorrow for H period) we continued learning about enzymes.  By the end of this class students were able to:

State that metabolic pathways consist of chains and cycles of enzyme- catalysed reactions.

Describe the induced-fit model.

Explain that enzymes lower the activation energy of the chemical reactions that they catalyse.

Below are the animations we used in class.

Blood clot formation is an example of a metabolic pathway.

Click here for an animation demonstrating a biochemical pathway.

Click here for the induced fit model animation.

Below is a great tutorial on energy and enzymes, click the picture to link to the tutorial.

Homework: A final reminder that your Design IA is due tomorrow in class.  You must submit a printed copy. 

Enzymes Internal Assessment

Today we spent half the period discussing your first official Internal Assessment and the remaining half of the class reviewing your test on Topics 3.1-3.5 and 7.1-7.4.

You will be investigating the decomposition of hydrogen peroxide by catalase.  

On Wednesday March 7th, you must submit a completed Design for this experiment.  Essentially this Design would be suitable for submission to the IB.  You will have Friday March 9th to play in class and tweak your design.  You will be graded on the Design that you submit on March 7th and this will be the last grade you have before midterms.

Your Design should have:

A Title

Research Question & Background Information

Null Hypothesis (Ho) and Alternative Hypothesis (Ha)

Table that lists the Independent & Dependent Variables, as well as Controls.

Materials (with uncertainties)

Photograph of experimental set up ** You do not need to include this at this time, however you do need to identify a space for it in your paper. ** You do not need to include a protocol diagram.

Method (listed in steps).

A data table

A couple of things to keep in mind: 

* Your lab design can not be identical to another student (even if they are in a different period).

* If you research information on this topic, you must cite it in your Design.  This includes information contained in the Background section.

* As you are designing the experiment be mindful of how you will collect the data, since you will actually be doing this experiment.

* Internal Assessments count for almost 25% of your overall IB grade.  Since unlike a test, you know exactly what your Internal Assessment will cover, you should take the extra time to make it perfect.

* Refer to the rubric you received for the Osmosis Design Lab for more details on the requirements.

Enzymes

Yesterday and today we started our work on Enzymes.  Today we finished 3.6 (core).  You all have the pink calendar for the next four weeks so that you can see where we are going and when you will have time to work on your internal assessment.

Today we used the simulation below to look at the effects of manipulating temperature, pH and substrate concentration on enzyme activity.

Tomorrow we will be talking about what enzymes you can use for the experiment as well as the equipment that is available.

Osmosis Design Practice

Yesterday and today students had the opportunity to 'play' in the lab using their experimental designs.  Here are some of the things they learned:

It's nearly impossible to transfer yogurt into dialysis tubing.

"Place half of the potato in water" is a completely unacceptable statement in a procedure.

Knowing what equipment is available will making writing a procedure much easier.

Measure in grams, not in "pinches" or "teaspoons."

After you've had a chance to 'play' it's OK and sometimes advisable to completely change your procedure.

Be Specific!
Be Specific!
Be Specific!

Tomorrow you will have class time to continue working on your designs.  The final design, following the guidelines you were given in class (at the back of the packet and have been emailed) will be due on Monday or Tuesday, depending on when your class meets.  You MUST have a printed copy of this assignment.

Experimental Design

Today we talked about experimental design and students were given the pages from the Syllabus that specifically address what assistance they can and can not receive from me.

After reviewing independent and dependent variables, we learned about the 5 x 5 model of experimental design.  Below is a sample 5 x 5 design for an experiment examining the effect of salt concentrations on the growth of bean seeds. 

On Monday or Tuesday of next week you will be carrying out this experiment. You will also have class on Wednesday to do this experiment as well.

You must come to class with the following information TYPED:  Refer to the pack you received in class today for the details of each section.

Planning (a):
         Question
         Hypothesis
         Variable chart


Planning (b):
        Protocol Diagram
        Procedure


Raw Data Table

Osmosis & Diffusion

Today we reviewed osmosis, diffusion and facilitated diffusion.  To see animations of each of these types of molecular movement check out these links:  osmosis, diffusion or facilitated diffusion

from: http://www.glogster.com/media/5/32/61/40/32614024.jpg

Tomorrow we will be talking about experimental design.  You will need to design an experiment that addresses the ONE of following questions:

How do different concentrations of a specific solution affect the rate of osmosis in potatoes?

OR:

How do different concentrations of a specific solution diffuse across a semi permeable membrane?

You have been emailed a series of documents (which you will also receive in class) that help you to plan out your experiment.

When you come to class tomorrow you need to have:

A hypothesis
Identified the independent variable
Identified the dependent variable
A list of things that you will need to control in this experiment

I can not emphasize this point enough:
You must complete this on your own.  You may do any research you like (CITE YOUR SOURCES!), however you can NOT work with a partner!

Practice IA for the data from Academic Travel

Yesterday afternoon we met with Mr. Merritt for an hour to recap our data from academic travel (see the data from Italy below).  He talked to us about the sampling method that his father, Dr. R. Merritt, has created over the past three decades!  Click on the picture to make it larger.

Today students worked on writing Aspects 2 & 3 of the conclusion and evaluation section of an Internal Assessment.

Students were also divided up into groups for their stream presentations on Friday.  Below are the groups.

E period:
Topic 1: Aleksa, Albert
Topic 2: Csilla, Thais, Angelika
Topic 3: Gabri, Lucia, Carlos
Topic 4: Sofia, Sebastian, Tselmeg

H period:
Topic 1: Zoe, Juan, Daniela
Topic 3: Alessandra, Juliana, Nicolo
Topic 4: Tim, Ignacio, Lud