So when is the test date for the topic 3 test?

Hi folks,

just a reminder that we will write the test for Topic 3 during next Wednesdays lesson (19th February). This lesson is compulsory for both SL and HL students as you all have to write the test on this day.

SL students you do not need to attend Mondays lesson (17th Feb) as we will be continuing with  additional higher level content on this day.

Remember, to be successful you will need to prepare. I suggest that you look first at the IB Syllabus statements for topic 3 (I posted the whole syllabus on my first Blog post), the relevant chapters in your text books, and the blog posts. Please note also that in this test I will assume that you know fully the content and ideas covered in Topics one and two.

PS I have posted the mark scheme for the practice questions on my last post. Use the past paper questions and the mark scheme to check your understanding


Respiration is NOT breathing!! Sorry to shout but you need to learn this fact.

Well this constitutes humour from Leonard!

downloaded from our friends at

With this kind of charm it is no wonder that Leonard gets to date Penny. If the attractiveness of your boyfriend/girlfriend were based upon your understanding of cellular respiration, what would your partner look like? (yes I know this is very shallow but how many of you would be dating someone who looks like this?)Taken from 10feb2014

Taken from 10feb2014


If you want to really understand Respiration then check out the relevant chapter in your text book, and THIS Slideshare and learn it!

Time for Enzymes

In todays lesson we will use THIS Slideshare from Stephen Taylor to understand the lock and key hypothesis and the induced fit hypothesis.

We will look at THIS animation and use it to investigate the effect of changing the temperature on the rate of an enzyme controlled reaction. We will collect data and present it as a DCP lab. The lab will be graded according to the IB Data Collection and Processing rubric. The IB rubric can be found in the IB sylabus and the modified rubrics which I introduced to you previously can be found here Modified IB Rubrics

Deoxyribosenucleic acid – this is such an important molecule, but do you know why?

Want to know why DNA is important, watch this little video for an introduction.


Now it’s time to study DNA, not just another biological molecule! Well actually it is, but it is very important. It is the molecule that is shared (with just very small variation) by every living organism on the planet – well all the ones we know about anyway. As the instrument of heredity it is well worthy of our study, together with how it replicates itself everytime that you grow a new cell. Now before you start to panic that it is going to be really complicated, ask yourself this question – ‘How complicated can DNA replication actually be if it occurs trillions of times in your  body with very few errors’? While it does seem complicated (especially with the language that we use), DNA is actually a very simple code.

We will shortly  extract DNA from  bananas. If you want to impress your friends and family by doing it at home, here is a delightful video showing you how to extract DNA from strawberries.

First we will look at DNA structure, check out

Then even more presentations from Mr. Taylor – this man is a veritible human dynamo when it comes to IB Bio presentations:

DNA structure

DNA replication

If after the last two lessons you are still struggling to get to grips with DNA replication then check out these summary notes. Can you use them to complete the activity from last class (re-arranging the key words)? DNA replication notes. AHL

Protein synthesis core

Protein synthesis HL

and finally here is a really useful powerpoint produced by Mrs. DickinsonProtein-Synthesis-AHL

Edit This

Anyone need a hand?


Several people have spoken to me about the slideshare we are using to learn about biological molecules, and are struggling to use it effectively. (It’s ok, different resources work for different people).  I am also aware that the SL students are still missing a text book. To help I have some supplementary notes that cover the same information which I have posted here for you Organic Compounds Notes if you dont like the slideshare. Thanks to Gretchen Kitchener for this.

While I am at it here are a few notes that support the additional higher level information you need to know about proteins.Additional HL notes about proteins.  and slide share if you are aiming for a level 6 or 7 I do recommend this slideshare(Topic 7.5), OR you can look at this powerpoint from Mrs. Nadine Dickinson which has the same information (but without polar molecules).Proteins AHL. We will look at these in more detail later – though if the HL students want to get ahead then ……..

In class today I will set you a homework on biological molecules, if you lose the printed version you can access it HERE

You are what you eat, but what do you eat? An investigation into food testing


There are so many questions that we need to be able to answer in this first section, some of which are given below:-

  • Can you distinguish between organic and inorganic compounds?
  • Can you identify carbohydrates, lipids and proteins from diagrams?
  • Can you explain the role of condensation and hydrolysis reactions between amino acids and polypeptides, between mono, di and polysaccharides, and between fatty acids, glycerol and triglycerides?
  • Can you compare the use of carbohydrates and lipids in energy storage?

To get the ball rolling we are going to start off with an investigation into foods by performing some food testing. In this practical Lab-Comparison-of-chemical-composition-of-food you will learn how to test everyday foods for Starch, Reducing sugars, proteins and lipids. This investigation will be another opportunity to practice writing conclusions and evaluations; I am looking forward to seeing which of you are reflective learners, will you learn from your previous mistakes? Look back at your first attempt at writing a conclusion and evaluation. Look also at this exemplar, for Conclusion and evaluation tips Draft Exemplar sa to vol lab, or in windows 2003 format here Draft Exemplar sa to vol lab

Once we have performed the lab we will use another slideshare from Stephen Taylor to learn about the Carbohydrates, Lipids and Proteins

While working through the slideshare some students told me about the following web site This site gives you access to ‘flash card’ type resources for a myriad of subjects, not just Biology. Just search within the site IB Biology (or any other subject that you want) and then find relevant resources. For a content heavy section like Biochemistry this could be very useful. Thanks to the students concerned for bringing it