1. Topic 2 – Molecular Biology
Explaining life’s mysteries through chemistry……
Or at least trying to.
Topics to be covered:
Metabolism
Water
Carbohydrates/Lipids
Proteins
Enzymes
Major Lab:
Investigation of the activity of enzymes

2. Molecular Biology came about because of the need for humans to distinguish “living” material from “non-living” material
So naturally, they set out to make urine in a lab…….
Vitalism – the belief that living organisms and non-living organisms have different properties
Called the “vitalistic element”, this was believed to distinguish living from non-living matter
This theory was disproved by a chemist – Friedrich Woehler.
He synthesized artificial urea by mixing cyanic acid and ammonium.
This discovery was the first time an organic substance was made from inorganic material

4. The Periodic Table of Elements!
Parts we care about are highlighted in green.
These elements are often used in the construction of Organic Compounds
Organic compounds are found in living organisms and contain carbon.
15 Minute Inquiry – Research one of the elements found in living systems and determine the following: -Structure (Draw it)
-Number of bonds it can form
-Uses in living systems
-Example of a compound found in the human body containing your element.
Compile your information on a whiteboard and turn in once done.

10. Carbon as the basis of all life – Why?
How many bonds can it form with other molecules?
What types of bonds is it going to form most of the time?

11. Carbon as the basis of all life – Why?
How many bonds can it form with other molecules?
4 – Due to a Carbon having only 4 electrons in its outer shell.
What types of bonds is it going to form most of the time?
Covalent – Due to the fact that Carbon is a non-metal, that will be interacting with other non-metals
Why is this ideal for biological systems?

12. Carbon as the basis of all life – Why?
How many bonds can it form with other molecules?
4 – Due to a Carbon having only 4 electrons in its outer shell.
What types of bonds is it going to form most of the time?
Covalent – Due to the fact that Carbon is a non-metal, that will be interacting with other non-metals
Why is this ideal for biological systems?
-Being able to make 4 bonds provides the most potential for diverse molecule structure, and thus, the highest potential for diverse biological components.
-Covalent bonds are strong when they need to be – long term security of molecule structure.

13. Carbohydrates Lipids Nucleic Acids
Organic compounds are constantly being changed within biological systems!
…..You all probably know this as Metabolism
Metabolism is the constant building and breaking down of carbon compounds to form the 4 major types of Organic Compounds:
Proteins
Carbohydrates Lipids Nucleic Acids

14. Drawing organic compounds for IB
Easy starting steps:
Draw the carbon atoms in each molecule.
Add the oxygen (O) or hydroxide (OH).
Add the nitrogen (N), if it is an amino acid.
Fill in the bonds in each atom with hydrogen(H) to make each atom stable
TRY IT WITH THE STRUCTURES BELOW!
Amino Acid
Saturated Fatty Acid
Monomer structures you need to know for IB

15. Monosaccharide Drawing Practice
Ways to know if a compound is Organic or Inorganic:
Organic compounds contain carbon always.
There is always at least one C-H bond in an organic molecule
Monosaccharide Drawing Practice
Look up the molecular structures of the three types of monosaccharides:
alpha-glucose
beta-glucose
ribose
And perform the following:
Draw each, using the proper method.
Look for unique features between each of the molecules, and circle them on your sheet.
Unique characteristics
Drawing
Title
Set up your sheet to look like this

16. AB A + B A + B AB Two major types of metabolic reactions – Catabolism
Anabolism
- the breaking down of complex organic compounds, resulting in simpler compounds
-the building up of organic compounds from
simpler compounds, resulting in more complex compounds
AB A + B
A + B AB
The reaction that performs anabolic action in the human body is called Condensation
The reaction that performs catabolic action in the human body is called Hydrolysis.

17. Condensation reactions make bonds. Hydrolysis bonds break these bonds.
Watch these three animations and make a
generalization about the processes:
function, reactants, products, role of water

23. Modelling Exercise – Showing Condensation and Hydrolysis
Work with a group to design an effective model of a monomer, dimer, and polymer. Using the materials provided, design a mini sketch, that will display the relationship between Condensation and Hydrolysis as the essential reactions for life to occur.
Organic Compounds to choose from –
Carbohydrates
Lipids
Proteins
You must have a separate color for each element, and be able to explain the following –
Where water is used
Where the components for water come from
Name of Monomers
Name of Dimer