What are the three main parts of the cell theory?

Question

List the five parts common to all cells.
What are the cell structures where proteins are made?
What is the role of DNA?
What is the cell nucleus?
What is the main difference between prokaryotic and eukaryotic cells?
Give an example of a prokaryotic cell.
Define organelle.
What is the advantage of having organelles?

Answer 1

Three Main Parts of the Cell Theory:

1. All living organisms are composed of one or more cells.
2. The cell is the basic unit of life.
3. All cells arise from pre-existing cells.

Five Parts Common to All Cells:

1. Cell membrane – a protective barrier that surrounds the cell.
2. Cytoplasm – the jelly-like substance inside the cell where organelles are suspended.
3. Ribosomes – the structures where protein synthesis occurs.
4. Genetic material (DNA) – hereditary material that contains the instructions for the cell's function and reproduction.
5. Cytoskeleton – a network of fibers that helps maintain the cell's shape and aids in movement.

Cell Structures Where Proteins Are Made:

• Ribosomes: These are the primary sites of protein synthesis. Ribosomes can be found floating freely in the cytoplasm or attached to the endoplasmic reticulum (ER), forming rough ER.

Role of DNA:

• DNA (Deoxyribonucleic Acid) carries the genetic instructions necessary for the growth, development, functioning, and reproduction of all known living organisms. It contains the sequence of nucleotides that determine the synthesis of proteins by encoding the messages that dictate what the cell should do.

What is the Cell Nucleus?

• The cell nucleus is a membrane-bound organelle that contains the cell's genetic material (DNA). It acts as the control center of the cell, regulating gene expression and overseeing cellular activities such as growth, metabolism, and reproduction.

Main Difference Between Prokaryotic and Eukaryotic Cells:

• The primary difference is that prokaryotic cells do not have a membrane-bound nucleus or other membrane-bound organelles, while eukaryotic cells do. Eukaryotic cells are typically larger and more complex than prokaryotic cells.

Example of a Prokaryotic Cell:

• Bacteria (e.g., Escherichia coli or Staphylococcus aureus) are common examples of prokaryotic cells.

Define Organelle:

• An organelle is a specialized subunit within a cell that has a specific function, often enclosed within its own membrane. Organelles perform various tasks that contribute to the cell's overall function, such as energy production, protein synthesis, and waste management.

Advantage of Having Organelles:

• The main advantage of having organelles is that they allow for compartmentalization within the cell, enabling different biochemical processes to occur simultaneously and efficiently in separate locations. This organization helps optimize cellular functions, enhances metabolism, and protects sensitive processes from interference.