The Cell Theory:
The Cell Theory states that all living things are made up of cells and that all cells come from pre-existing cells. It also states that the cell is the basic unit of life - structures and functions.
The cell is a remarkable phenomenon that is the foundation of all life forms. This blog will examine the cell with particular focus on its internal structure.
Let's examine the basic structures that are common amongst both plant and animal cells:
In terms of function, the nucleus serves as the control center for the cell; it is where the genetic information is stored. In the form of chromosomes, DNA strands are condensed around proteins. Further,the nucleus also contains nucleoli which are responsible for producing ribosomes, which will be discussed later in this blog.
Rough endoplasmic reticulum is covered with ribosomes. It aids in synthesizing proteins, adds carbohydrates to proteins to create glycoproteins and produces new membranes.
Smooth endoplasmic reticulum is responsible for synthesizing lipids, metabolizing carbohydrates, detoxification and calcium ion storage.
In terms of function, the ribosomes role is to synthesize proteins.
A cell's golgi apparatus is responsible for the modification of proteins, the carbohydrates added to proteins and phospholipids. It is also involved in the synthesis of phospholipids as well as sorting and releasing products in vesicles.
It is involved in digestion, storage, waste disposal, water balance, cell growth and protection.
It contains enzymes that can transfer hydrogen atoms to oxygen producing hydrogen peroxide which is then converted to water by yet another enzyme.
This organelle plays a key role in cellular respiration, which we will learn about in a future blog post.
Cell wall - This outer layer of plant cells enable them to maintain their shape and serves as a method of protection. Further, it is made mostly of cellulose.
Chloroplast - this photosynthetic organelle can convert solar energy into potential chemical energy which plants and animals rely on to thrive. We will explore this process in a future blog.
In animal cells ONLY:
Lysosome - Lysosomes are known as the cell's 'clean up crew'. They are responsible for digestion. Macromolecules are hydrolyzed within them.
Centrosome - This is a region within the cell where the cells microtubules are initiated. It contains a pair of centrioles and plays a key role in the division of animal cells.
Flagella - This structure is only found in some animal cells. It allows for motility of certain cells. Sperm cells would be an example.