Learning Outcomes
i. Define cytoplasm and describe its chemical nature.
ii. Explain the metabolic roles of the cytoplasm.
iii. Describe the critical functions performed by the cytoplasm in the cell.
i. Definition and chemical nature of cytoplasm: The cytoplasm is the gel-like substance that fills the cell between the plasma membrane and the nucleus. It is made up of water, dissolved molecules, and organelles. The main components of the cytoplasm are:
Water: Water is the major component of the cytoplasm, making up about 70% of its volume.
Dissolved molecules: The cytoplasm contains a variety of dissolved molecules, including ions, sugars, amino acids, and proteins. These molecules are essential for cellular metabolism and function.
Organelles: Organelles are specialized structures that carry out specific functions in the cell. The cytoplasm contains a variety of organelles, including the mitochondria, ribosomes, and Golgi apparatus.
ii. Metabolic roles of the cytoplasm: The cytoplasm is the site of many metabolic reactions. Metabolism is the sum of all the chemical reactions that occur in a cell. These reactions include:
Glycolysis: Glycolysis is the process of breaking down glucose to produce ATP, the energy currency of the cell.
Kreb's cycle: The Krebs cycle is a series of chemical reactions that further break down glucose and other molecules to produce ATP.
Oxidative phosphorylation: Oxidative phosphorylation is the process of using oxygen to produce ATP from NADH and FADH2, two molecules that are produced during glycolysis and the Krebs cycle.
Protein synthesis: Protein synthesis is the process of building proteins from amino acids.
Lipid metabolism: Lipid metabolism is the process of breaking down and building lipids, such as fats and oils.
Carbohydrate metabolism: Carbohydrate metabolism is the process of breaking down and building carbohydrates, such as sugars and starch.
iii. Critical functions performed by the cytoplasm: In addition to its metabolic roles, the cytoplasm also performs a number of other critical functions in the cell, including:
Support and structure: The cytoplasm provides support and structure for the cell. It also helps to maintain the cell's shape.
Transport: The cytoplasm transports molecules throughout the cell. This includes transporting molecules from the cell membrane to the organelles and from the organelles to the cell membrane.
Communication: The cytoplasm is involved in cell communication. It allows molecules to pass between different parts of the cell and between different cells.
Cell division: The cytoplasm is involved in cell division. It helps to separate the chromosomes during mitosis and meiosis.
The cytoplasm is a vital part of the cell. It provides support and structure for the cell, transports molecules throughout the cell, is involved in cell communication, and plays a role in cell division. The cytoplasm is also the site of many metabolic reactions, including glycolysis, the Krebs cycle, oxidative phosphorylation, protein synthesis, lipid metabolism, and carbohydrate metabolism.
