Inside the Cell

Our bodies are made of cells. Understanding the biology of the cell, its structure and its functions is the first step in understanding how our muscles work and what it means to have a pathogenic mutation in the FKRP gene and be diagnosed with LGMD2I. A lot of information about cell biology is already available on the internet (see “More Information”). What we believe is most important for you to know is the following.

Four main types of molecules make a cell

All of the cells of our body are identical in their basic structure and in the way they function.

Cells use 4 types of molecules: ¹Nucleic acids, ²proteins, ³carbohydrates (sometimes confused with sugars), ⁴lipids (sometimes confused with fats).

1. Nucleic acids: These molecules store information and guide the activity or fate of other molecules.
2. Proteins: Proteins represent the cell’s labor force, with specialized proteins for each of the thousands of processes occurring in the cells. Because proteins build the other three types of molecules, creating the right set of proteins is the cell’s priority.  Proteins can be used to build structure like the myofibril, rod-like structures that fill the muscle cells and allow them to change size.
3. Carbohydrates: Two main roles, one of which is to provide energy to the cell. The other role is to give new attributes to the proteins they are attached to. A specific protein without its specific carbohydrate will not perform its specific function.
4. Lipids: They are most famous for being the structural components of cell membranes and of the membranes of organelles inside the cells. They are also used to store energy and send signals inside the cells and between cells.

More Information:

• NIH Seer Training Module: Introduction to the Human Body
• NIH Inside the Cell: Chapter 2: Cells 101: Business Basics
• Basic Biology: Molecules of Life
• Biology4kids.com: Cells are the Starting Point