Do Plant and Animal Cells Have Cytoplasm?

Both plant and animal cells contain cytoplasm, the gel-like material that fills the space between the cell membrane and the nucleus. This is one of the features the two cell types share without exception. But while both kingdoms check the same box on a biology worksheet, their cytoplasm is not identical. The organelles suspended in it, the way it moves, and even how it splits during cell division differ in ways that reflect over a billion years of evolutionary divergence.

What Cytoplasm Actually Is

Cytoplasm is everything inside the cell membrane except the nucleus. That includes the cytosol, which is the liquid portion, along with all the organelles, protein complexes, and filament networks floating or anchored within it. Scientists once called the whole living interior of a cell “protoplasm,” a term that dominated biology for over a century before being replaced by more precise language as researchers began distinguishing between the nucleus and the surrounding material.¹

The cytosol itself is mostly water, but it is far from an empty solution. It is packed with dissolved ions, small molecules, and an enormous concentration of proteins and RNA. Researchers have compared it to a crowded party in a house full of furniture, in contrast to the common mental image of molecules bouncing around in open space.² That crowding matters because it changes how molecules find each other, how fast reactions happen, and how signals travel from one end of a cell to the other.

The Organelles That Make Plant and Animal Cytoplasm Different

The core set of organelles is largely the same in both cell types. Both have mitochondria for energy production, an endoplasmic reticulum for protein processing, ribosomes for building proteins, and a Golgi apparatus for packaging and shipping molecules. But each kingdom has structures the other lacks, and those differences shape what the cytoplasm looks like under a microscope and what it can do.

The most obvious difference is chloroplasts. Plant cells contain these organelles, which carry out photosynthesis, while animal cells do not.³ Plant cells also have a large central vacuole that can occupy most of the cell’s volume, pushing the rest of the cytoplasm into a thin layer against the cell wall. Animal cells have smaller vacuoles, if any. Meanwhile, animal cells contain centrioles, structures involved in organizing cell division, and prominent lysosomes for breaking down waste. A systematic comparison of these organelles shows that while the core machinery is conserved, specialized structures like chloroplasts and large vacuoles in plants versus centrioles and lysosomes in animals reflect distinct evolutionary paths.⁴

The Golgi apparatus itself also behaves differently. In animal cells, the Golgi tends to sit near the nucleus as a single, interconnected ribbon-like structure. In plant cells, it is scattered throughout the cytoplasm as many smaller, independent stacks. Differences extend to how the Golgi replicates during cell division, how it anchors itself within the cytoplasm, and how it handles secretion.⁵

The Cytoskeleton Running Through It

Suspended within the cytoplasm of animal cells is a cytoskeleton made of three main filament types: actin filaments, microtubules, and intermediate filaments. Together they handle an impressive range of jobs, from maintaining cell shape to enabling cell division, internal transport, and movement. This network is highly dynamic, reorganizing itself within minutes in response to signals from inside or outside the cell.⁶ Detailed imaging has shown that the actin portion of this network extends throughout the cytoplasm, forming an interconnected three-dimensional mesh that links structures at the cell surface to those deep inside.⁷

Plant cells also have actin filaments and microtubules, but they lack the intermediate filaments found in animal cells. They compensate in part with their rigid cell wall, which provides much of the structural support that intermediate filaments supply in animal cells. The plant cytoskeleton is heavily involved in guiding the deposition of new cell wall material and in directing the flow of cytoplasm, a process that becomes especially dramatic in large plant cells.

Cytoplasmic Streaming in Plants

One of the most visually striking things about plant cytoplasm is that it moves. In large plant cells, the cytoplasm flows in a continuous circuit around the inside of the cell, a phenomenon called cytoplasmic streaming. You can watch it happen under a basic light microscope in cells like those of the aquatic plant Elodea: chloroplasts and other organelles travel along well-defined paths as if riding a slow conveyor belt.

The driving force behind this movement is well understood. Myosin motor proteins, attached to organelles, walk along tracks of actin filaments anchored near the cell’s outer edge. As these motor-coated organelles move, they drag the surrounding cytoplasm along with them.⁸ The result is a bulk flow that distributes nutrients, chemical signals, and organelles throughout cells that can be far too large for diffusion alone to handle the job. Some plant cells are centimeters long, and without streaming, a molecule released at one end would take an impractically long time to reach the other.

Animal cells don’t typically show this kind of large-scale cytoplasmic streaming, mainly because they tend to be much smaller. Diffusion and active transport along cytoskeletal tracks handle intracellular distribution without needing a bulk flow of the entire cytoplasm.

The Surprising Physics of Cytoplasm

If you think of cytoplasm as a thin liquid, the reality is more interesting. Cytoplasm behaves as a viscoelastic material, meaning it acts partly like a liquid and partly like a gel depending on how quickly you push on it. Studies probing the interior of living cells have found that for objects larger than about a micron, the cytoplasm flows like a fluid at longer timescales but resists deformation like an elastic solid at shorter ones.⁹

Work using tiny fluorescent probes inside living cells has confirmed this pattern across multiple cell types. At low frequencies, the viscous component dominates: push gently and slowly, and the cytoplasm flows. But at higher frequencies, an elastic component kicks in.¹⁰ More recent measurements spanning a very broad frequency range have found that the cytoplasm’s mechanical response follows a consistent pattern that holds up even when researchers disrupt the cytoskeleton with drugs, suggesting the behavior is an inherent property of the crowded cytoplasmic fluid itself rather than just the filament network.¹¹

This physical behavior matters because it affects everything from how organelles move through the cell to how mechanical forces are transmitted during processes like cell division or migration. The cytoplasm isn’t just a passive container; its mechanical properties help organize and regulate what happens inside the cell.

Glycolysis and Metabolic Work in the Cytoplasm

Both plant and animal cells carry out glycolysis, the foundational metabolic pathway that breaks down glucose, in their cytoplasm. Glycolysis does not require any organelle; its enzymes are dissolved directly in the cytosol. The pathway converts glucose into pyruvate while generating a small amount of energy that the cell can use immediately. It also produces the chemical building blocks that feed into mitochondria for further energy extraction or get redirected into pathways that make amino acids, lipids, and other molecules the cell needs.¹²

This shared feature is a good reminder that the basic metabolic machinery of life operates in the cytoplasm regardless of which kingdom a cell belongs to. The downstream details differ: plant cells can also fix carbon from carbon dioxide through photosynthesis in their chloroplasts, and the products of that process eventually cycle through the same cytoplasmic pathways. But the cytoplasm as a metabolic workbench is universal.

How Plant and Animal Cells Divide Their Cytoplasm

When a cell divides, it has to split not just its DNA but also its cytoplasm into two daughter cells. This step, called cytokinesis, is where plant and animal cells diverge dramatically. Animal cells pinch inward: a ring of actin and myosin proteins assembles at the cell equator and contracts like a drawstring, squeezing the cytoplasm in two. Plant cells cannot do this because they are enclosed in a rigid cell wall. Instead, they build a new wall from the inside out, assembling a structure called the cell plate from vesicles that bud off the Golgi apparatus and fuse together at the center of the cell, gradually expanding outward until they reach the existing cell wall.¹³¹⁴

The outcome is the same: two cells, each with its own cytoplasm and complement of organelles. But the mechanics are almost opposite. Animal cytokinesis works from the outside in; plant cytokinesis works from the inside out. Both strategies have to distribute the cytoplasmic contents fairly evenly, ensuring each daughter cell gets enough mitochondria, ribosomes, and other machinery to survive.

Cytoplasmic Inheritance

Not all genetic information lives in the nucleus. Mitochondria carry their own small genomes, and in plant cells, chloroplasts do too. Because these organelles sit in the cytoplasm, they are inherited through a different set of rules than nuclear genes. When an egg cell is fertilized, the sperm contributes almost no cytoplasm, so the mitochondria (and, in plants, chloroplasts) come overwhelmingly from the maternal parent. This pattern is called uniparental inheritance, and it is one of the distinctive features of cytoplasmic genetics.¹⁵

In plants, this gets more complicated because there are two separate cytoplasmic genomes to track: the mitochondrial genome and the plastid genome. Which parent passes them on can vary between species, and the organelles also undergo a process called vegetative segregation, where their genomes sort randomly as the organelles divide within a growing cell. The practical consequence is that siblings from the same cross can end up with different ratios of cytoplasmic gene variants, something that doesn’t happen with nuclear genes and their predictable patterns.

How Cells Communicate Through Cytoplasm

Cytoplasm does not exist in isolation. In living tissues, cells need to exchange signals and small molecules with their neighbors, and the routes they use differ between plants and animals. Plant cells are connected by plasmodesmata, tiny channels that thread through the cell wall and directly link the cytoplasm of adjacent cells. These channels allow molecules to pass between cells and play key roles in regulating plant development and differentiation. Animal cells, lacking a rigid wall, use structures called gap junctions for short-range communication and tunneling nanotubes for longer-range exchanges.¹⁶

The existence of plasmodesmata means that in a plant tissue, the cytoplasm of many cells can be functionally continuous, forming a shared network called the symplast. This is quite different from animal tissues, where each cell’s cytoplasm is more self-contained, with communication happening through small molecules that pass through gap junction channels or through signaling molecules secreted and received at the cell surface. Live-cell imaging of plant tissues has demonstrated this connectivity directly: fluorescent dyes confined to the cytoplasm of live cells remain contained within cells that have closed their plasmodesmata but spread to neighbors through open ones.¹⁷

Stress Granules and Phase Separation

One of the more surprising discoveries of recent years is that the cytoplasm can spontaneously organize itself without membranes. Under stress conditions like heat shock, viral infection, or nutrient deprivation, proteins and RNA molecules in the cytoplasm can separate out of the surrounding fluid and form dense droplets, much the way oil separates from vinegar. This process, called liquid-liquid phase separation, produces structures known as stress granules in both plant and animal cells.¹⁸

Stress granules are temporary holding areas for messenger RNA molecules that the cell has stopped translating while it deals with a crisis. When the stress passes, the granules dissolve and the mRNAs re-enter the normal translation machinery. This is an elegant example of how the physical chemistry of cytoplasm, specifically its crowded, concentrated nature, enables a form of organization that doesn’t require building a new membrane-bound compartment from scratch. Viruses can hijack this same process, and when phase separation goes wrong, it has been linked to neurodegenerative diseases where protein aggregates accumulate in the cytoplasm and refuse to dissolve.

pH Balance in the Cytoplasm

The cytoplasm’s chemical environment is tightly regulated, and pH is one of the most critical parameters. Most cells maintain their cytoplasmic pH within a narrow range, roughly 7.0 to 7.4, through a combination of ion pumps, chemical buffers, and metabolic reactions that consume or produce hydrogen ions. When this regulation breaks down, the consequences are severe.

Plant cells under low-oxygen conditions illustrate this vividly. When roots are flooded and oxygen becomes scarce, cells switch from aerobic metabolism to fermentation, which generates acid. The cytoplasm acidifies by roughly half a pH unit as an early response to oxygen deprivation. If the plant is tolerant of low oxygen, this lower pH can stabilize for a while. But in less tolerant species, the pH continues to drop as the cell’s energy supply fails, eventually destroying the cell’s ability to maintain the chemical gradients across its membranes, which leads to cell death.¹⁹ Animal cells face analogous challenges during oxygen deprivation, such as during a heart attack or stroke, where cytoplasmic acidification contributes to tissue damage.

Watching Cytoplasm in Real Time

Much of what we know about cytoplasm in living cells comes from fluorescence imaging techniques that let researchers tag specific molecules with glowing proteins and watch them in action. Fluorescent protein tags and live-cell dyes provide tools to investigate virtually any cellular process under the microscope.²⁰ One striking application involves engineering cells to express one color of fluorescent protein in the nucleus and a different color in the cytoplasm. This dual-color approach lets researchers watch the cytoplasm and nucleus simultaneously, tracking changes in cell shape, the ratio of nuclear to cytoplasmic volume, and the dynamics of cell division in real time.²¹

These imaging tools have been applied to both plant and animal cells. In plant research, fluorescent dyes that stay confined to the cytoplasm of living cells have been used to track cell death in real time during fungal infection, revealing how the integrity of the cytoplasm degrades as a pathogen spreads from cell to cell.¹⁷ The progression is visible: a healthy cell shows dye restricted to the thin cytoplasmic layer around the vacuole, a dying cell shows the dye spreading as the vacuole collapses, and a dead cell loses fluorescence entirely. Being able to watch these transitions has transformed the study of cytoplasm from a static, stained-slide discipline into one where scientists can see the living material behave.

What About Prokaryotes

The question in the title specifies plant and animal cells, but it is worth noting that bacteria and archaea also have cytoplasm. In fact, every known living cell does. The difference is that prokaryotic cells lack a membrane-bound nucleus, so their DNA floats freely in the cytoplasm alongside everything else. Their cytoplasm also appears to lack the elaborate cytoskeletal network found in eukaryotic cells.²² This doesn’t mean prokaryotic cytoplasm is structurally featureless; bacteria have filament-forming proteins that help with cell shape and division, but they are organized differently and are far simpler than the actin-microtubule-intermediate filament system of animal cells or the actin-microtubule system of plants.

The universality of cytoplasm across all domains of life underscores how fundamental it is. It isn’t a quirk of eukaryotic cell design. It is the medium in which life’s chemistry happens, and every cell on Earth relies on it.