General Approach to Biomolecule Types in BIS2A
Before you start
If necessary please review the Design Challenge module to review the Design Challenge rubric.
Some context and motivation
In BIS2A, we are concerned primarily with developing a functional understanding of a biological cell. In the context of a design problem, we might say that we want to solve the problem of building a cell. If we break this big task down into smaller problems, or alternatively, ask what types of things do we need to understand in order to do this, it would be reasonable to conclude that understanding what the cell is made of would be important. That said, it isn't sufficient to appreciate WHAT the cell is made of. We also need to understand the PROPERTIES of the materials that make up the cell. This requires us to dig into a little bit of chemistry—the science of the "stuff" (matter) that makes up the world we know.
This prospect of talking about molecular chemistry and thermodynamics makes some students of biology apprehensive. Hopefully, however, we will show that many of the vast number of biological processes that we care about arise directly from the chemical properties of the "stuff" that makes up life and that developing a functional understanding of some basic chemical concepts can be tremendously useful in thinking about how to solve problems in medicine, energy, and environment by attacking them at their core.
Importance of chemical composition
As a student in BIS2A, you will be asked to classify macromolecules into groups by looking at their chemical composition and, based on this composition, also infer some of the properties they might have. For example, carbohydrates typically have multiple hydroxyl groups. Hydroxyl groups are polar functional groups capable of forming hydrogen bonds. Therefore, some of the biologically relevant properties of various carbohydrates can be understood at some level by a balance between how they may tend to form hydrogen bonds with water, themselves or other molecules.
Linking structure to function
Each macromolecule plays a specific role in the overall functioning of a cell. The chemical properties and structure of a macromolecule will be directly related to its function. For example, the structure of a phospholipid can be broken down into two groups, a hydrophilic head group and a hydrophobic tail group. Each of these groups plays a role in not only the assembly of the cell membrane but also in the selectivity of substances that can/cannot cross the membrane.