Introduction

All cells (Eukaryotes and Prokaryotes) share four common components: 1) a plasma membrane, an outer covering that separates the cell’s interior from its surrounding environment; 2) cytoplasm, consisting of a jelly-like cytosol within the cell in which the other cellular components are suspended; 3) DNA, the cell’s genetic material; and 4) ribosomes, which synthesize proteins.

This section will examine the cytoplasm.

Learning

Cytoplasm

Inside the plasma membrane there is a thick, usually colorless solution. This substance pushes against the plasma membrane and helps give the cell its shape. It does not have any structure itself, but it is organized. There is a protein scaffold located in the cytoplasm called the cytoskeleton that gives the cell its structure.

In eukaryotic cells the organelles are suspended in the cytoplasm. The cytoplasm located around the organelles is referred to as the cytosol. This is a waterier form of the cytoplasm.

There are many other organic molecules located in the cytosol as most of the cell’s metabolic processes occur in this region of the cell. Some of the organic molecules found in the cytoplasm are glucose, other sugars, polysaccharides, amino acids, nucleic acids, and fatty acids. In addition, there are dissolved ions such as sodium, potassium, and calcium.

Prokaryotic cells also have cytoplasm, located inside the plasma membrane. They do not have organelles but have ribosomes located in the cytoplasm.

This is an artist’s rendering of the cytosol, showing microtubules (light blue), actin filaments, both part of the cytoskeleton (dark blue), ribosomes (yellow and purple), soluble proteins (light blue), kinesin (red), small molecules (white) and RNA (pink). This representation shows that the cytoplasm is packed with many necessary components that allows the cell to function.

Cytoplasm Studies

Researchers in Germany in 2016 discovered that cells when they are deprived of nutrients can appear to become dormant. The study showed that nutrient deprivation leads to the cell shut down metabolic activities. When the cell does not have the necessary nutrients, pH shifts and energy levels drop significantly. The cytoplasm then changes form and enters a more solid state. The cells appear to be dead. The researchers believe this is a protection mechanism to save the organelles. When nutrients are introduced back, the cells recover and continue to divide and function.

Summary

• The cytoplasm is a thick, usually colorless solution that fills each cell and is enclosed by the cell membrane.
• It helps to give the cell its shape
• In eukaryotic cells the organelles are suspended in the cytoplasm
• The cytoplasm located around the organelles is referred to as the cytosol (waterier).
• Other things found in the cytoplasm include biological molecules and dissolved ions.
• Prokaryotic cells also have cytoplasm.

Sources:

“Components of Prokaryotic Cells.” By OpenStax Biology 2e. Retrieved from: https://openstax.org/books/biology-2e/pages/4-2-prokaryotic-cells Licensed under: CC-By: Attribution

Wakim, S., & Grewal, M. (2019, May 19). Cytoplasm and Cytoskeleton. Retrieved June 3, 2021, from https://bio.libretexts.org/@go/page/22465

“Cytoplasm and Cytoskeleton” by Suzanne Wakim & Mandeep Grewal, LibreTexts is licensed under CC BY-SA .

Wakim, S., & Grewal, M. (2020, May 13). Cytoplasm and Cytoskeleton. Retrieved June 3, 2021, from https://bio.libretexts.org/@go/page/30624