Essential Idea
Living organisms control their composition by a complex web of chemical reactions.
Essential Idea
Molecular biology explains living processes in terms of the chemical substances involved.
Carbon atoms can form four covalent bonds allowing a diversity of stable compounds to exist.
Life is based on carbon compounds including carbohydrates, lipids, proteins and nucleic acids.
Metabolism is the web of all the enzyme-catalysed reactions in a cell or organism.
Anabolism is the synthesis of complex molecules from simpler molecules including the formation of macromolecules from monomers by condensation reactions.
Catabolism is the breakdown of complex molecules into simpler molecules including the hydrolysis of macromolecules into monomers.
Applications
Urea as an example of a compound that is produced by living organisms but can also be artificially synthesized.
Skills
Drawing molecular diagrams of glucose, ribose, a saturated fatty acid and a generalized amino acid (VIDEO).
Identification of biochemicals such as sugars, lipids or amino acids from molecular diagrams.
Guidance
Only the ring forms of D-ribose, alpha–D-glucose and beta-D-glucose are expected in drawings.
Sugars include monosaccharides and disaccharides.
Only one saturated fat is expected and its specific name is not necessary.
The variable radical of amino acids can be shown as R. The structure of individual R-groups does not need to be memorized.
Students should be able to recognize from molecular diagrams that triglycerides, phospholipids and steroids are lipids. Drawings of steroids are not expected.
Proteins or parts of polypeptides should be recognized from molecular diagrams showing amino acids linked by peptide bonds.
Key Vocabulary
Chemical Bonding
Covalent
Ionic
Carbon Compounds
Metabolism
Catabolism
Anabolism
Textbook Reading and/or Activities
Click HERE for a pdf of chapter 2.
Challenge Yourself (p.55)
ToK (p.55)
Challenge Yourself (p.61-62)
Exercises (p.62-63)
Notes
A detailed set of notes, prepared by Bob Smullen, examining all of the IB learning expectations.
A detailed set of notes, created by Chris Paine, examining all of the IB learning expectations.
A series of questions, created by Chris Paine, to help check your understanding of the IB learning expectations. This is VERY GOOD practice.
A detailed set of notes, prepared by Jacob Cedarbaum, examining all of the IB learning expectations.
A series of questions, prepared by Jacob Cedarbaum, to help check your understanding of the IB learning expectations. This is VERY GOOD practice. Answers.
The following sets of notes are provided to help you refresh your understanding of the basics of chemistry.
Learning Activities
"Why Carbon is a Tramp" by Crash Course (12:32)
This video discusses the properties of carbon and why those properties make it such a versatile atom; an atom upon which life has evolved.
This simulation, prepared by PhET, will help you better understand how polarity influences the interaction between two atoms as well as an entire molecule.
Supplemental Readings
The Metabolic Process
The following is a short read (1 page) from Education Portal. You can choose to pay (booo) to watch the complete video or take the quiz but reading the page will probably be helpful enough. We will see these concepts again as we continue with this Topic.