Chapter 1 – Cell Biology
Cells are just like little people. They eat, drink, excrete, etc. Review the
general structure of the cells, their parts and their functions. We (or “EU)
are eukaryotic cells that have a nucleus which not only holds our genetic
material, but the nucleus also creates proteins and allows the cell to
replicate.
DNA holds our unique genetic code in the nucleus and RNA (there are
several types but in general) it is important as the transfer shuttle to make
protein in the cytosol of the cell. Those proteins then create many of the
structures of the body.
• DNA
o Basic structure and the bases in DNA
• RNA bases
o Basic structure and the bases in RNA
There are many other important organelles in the cytoplasm. Know them
and their basic functions. Also, the cell membrane is what helps cells to
interact with other cells and also to maintain the integrity of the inside of
the cell. There must be a balance of electrolytes such as sodium (Na) and
potassium (K) inside and outside of cells, as well as fluids, etc. The cell
membrane has several structures that allow it to interact with its
environment and also to monitor what allows things in and out. Know
these structures.
Cells metabolize material just as we do. They break structures down, aka
catabolism, and they build structures up, aka anabolism (such as anabolic
steroids). Cells use ATP for energy. ATP is created in mitochondria aka the
, power house of the cell. ATP is stored energy ready to be used when we
need it.
• Metabolism – catabolism and anabolism
ATP is created by a very complex process called the Citric acid cycle, aka the
Kreb’s cycle. When oxygen and glucose are present, there is a lot of ATP
created in cells in the mitochondria. Oxygen and glucose are sent to the
mitochondria and create ATP via the Citric acid cycle. Glycolysis is the first
step of this process (occurs outside the mitochondria) , then oxidative
phosphorylation (which occurs in the mitochondria) creates a lot of ATP
through very complex processes.
ATP can be created with lipids (aka fats) in the Citric acid cycle but creates
about half the ATP, and protein can be used to create ATP in the Citric acid
cycle, but this means we will break down the structures of the body. This is
where wasting and anorexia shows up, as we use our muscle and body
proteins for energy.
If there is no oxygen, we can still create energy, but it creates very little
(anaerobic glycolysis) and its byproduct is lactic acid. This is why sprinting
causes painful muscles the next day. The muscles squeeze so hard, they
have no oxygen, and we deposit lactic acid.
Substances move in and out of cells either passively or actively. The main
difference is active uses energy, aka ATP!
• Active transport
• Solutions in the body are made up of Solute and Solvent o Made up
of solute which are the substances in the solution. Examples of
solute in our bodies are fats, proteins, salt, potassium etc.
o Also made up of solvent, which is the fluid. In our bodies
water is the solvent
• Diffusion