Difference Between Plant Cell and Animal Cell — Complete Guide

The main differences are: Plant cells have a cell wall (made of cellulose) — animal cells do not. Plant cells have chloroplasts for photosynthesis — animal cells do not. Plant cells have a large central vacuole — animal cells have small, multiple vacuoles. Animal cells have centrosomes/centrioles — plant cells generally do not. Plant cells have a fixed rectangular shape; animal cells are irregular. These differences reflect the different lifestyles — plants are stationary and photosynthesise; animals move and eat.

The cell wall of plant cells is made primarily of cellulose — a polysaccharide (complex carbohydrate) composed of glucose units. It is a rigid structure outside the cell membrane. Functions: provides structural support; gives the plant cell its fixed shape; allows high turgor pressure (turgidity); protects the cell. Animal cells have NO cell wall — just the flexible cell membrane. (Note: Fungi have cell walls made of chitin; bacteria have cell walls made of peptidoglycan — these are different from cellulose.)

Plant cells have chloroplasts because plants are autotrophs — they make their own food through photosynthesis using sunlight, water, and CO₂. Chloroplasts contain chlorophyll (the green pigment that absorbs light) and the enzymes needed for photosynthesis. Animal cells do not have chloroplasts because animals are heterotrophs — they cannot make their own food and must consume plants or other organisms for energy. Since animal cells don't photosynthesise, they have no need for chloroplasts.

The central vacuole is a large membrane-bound compartment in plant cells that can occupy up to 90% of the cell's volume. It is filled with cell sap (water, dissolved salts, sugars, and waste products). Functions: Maintains turgidity (firmness) of the cell through turgor pressure — this is what keeps non-woody plants upright. Stores nutrients and waste products. Creates cell sap pressure that pushes the cytoplasm and nucleus to the periphery. Animal cells have no large central vacuole — they have small, temporary vacuoles.

Centrioles are cylindrical structures found in the centrosome of animal cells. Their role: During cell division (mitosis), centrioles form the mitotic spindle — a structure of protein fibres that attach to chromosomes and pull them to opposite poles of the cell, ensuring each daughter cell receives the correct number of chromosomes. Plant cells (higher plants) generally lack centrioles but can still form spindle fibres through alternative mechanisms. The presence of centrioles in animal cells and their absence in plant cells is an important difference.

Plant cells store energy primarily as starch — a polysaccharide made of glucose units, stored in amyloplasts (a type of leucoplast). This is why potatoes, wheat, and rice are starchy. Animal cells store energy as glycogen — also a polysaccharide made of glucose units, stored mainly in liver and muscle cells. Both starch and glycogen are made from glucose, but they have different branching structures. When energy is needed, both are broken back down into glucose.

Plastids are membrane-bound organelles found ONLY in plant cells (and algae). Types: Chloroplasts — contain chlorophyll, carry out photosynthesis, give plants their green colour. Chromoplasts — contain coloured pigments (carotenoids, xanthophylls), give red, orange, and yellow colour to fruits and flowers. Leucoplasts — colourless plastids for storage: amyloplasts store starch; elaioplasts store oils; proteinoplasts store proteins. Animal cells have no plastids of any kind.

Cytokinesis is the division of the cytoplasm after nuclear division (mitosis). In plant cells: A cell plate forms in the middle of the cell. Vesicles from the Golgi apparatus fuse to form the plate, which grows outward to the cell wall. The cell plate eventually becomes the new cell wall separating the two daughter cells. In animal cells: A cleavage furrow forms — the cell membrane is pinched inward by a contractile ring of actin filaments, eventually dividing the cell in two. The difference reflects the plant cell's rigid wall (can't be pinched) vs. animal cell's flexible membrane.