PLANT CELL
What is a Plant Cell?
A plant cell is the basic structural and functional unit of plants.It is eukaryotic, meaning it has a true nucleus and membrane-bound organelles.Plant cells are unique because they can photosynthesize and have a rigid cell wall.
🧱 1. Cell Wall
Outermost layer of the plant cell
Made mainly of cellulose
Rigid and non-living
Functions
Gives shape and support
Protects the cell from damage
Prevents the cell from bursting due to excess water (turgidity)
🌊 2. Plasma (Cell) Membrane
Thin, living membrane just inside the cell wall
Selectively permeable
Functions
Controls movement of substances in and out
Maintains internal balance (homeostasis)
💧 3. Cytoplasm
Jelly-like fluid inside the cell
Contains enzymes and organelles
Functions
Site of many metabolic reactions
Helps in transport of materials inside the cell
🧠 4. Nucleus
Large, round structure
Surrounded by a nuclear membrane
Contains DNA (genes)
Functions
Controls all cell activities
Stores hereditary information
Helps in cell division
🟢 5. Chloroplast (Only in Plant Cells)
Green, oval-shaped organelle
Contains chlorophyll
Functions
Site of photosynthesis
Converts sunlight → chemical energy (glucose)
Internal Structure
Grana – stacks of thylakoids (light reaction)
Stroma – fluid part (dark reaction)
🧃 6. Vacuole (Large Central Vacuole)
Occupies up to 90% of the cell
Filled with cell sap
Functions
Stores water, salts, sugars, and wastes
Maintains turgor pressure
Helps cell stay firm and upright
🏭 7. Mitochondria
Known as the powerhouse of the cell
Bean-shaped with inner folds (cristae)
Functions
Site of cellular respiration
Produces ATP (energy)
📦 8. Endoplasmic Reticulum (ER)
Rough ER
Has ribosomes
Protein synthesis
Smooth ER
No ribosomes
Lipid synthesis and detoxification
⚙️ 9. Golgi Apparatus
Stack of flattened sacs
Functions
Modifies, packages, and transports proteins
Secretion of substances
🔹 10. Ribosomes
Very small, non-membranous
Free or attached to ER
Function
Protein synthesis
🧬 11. Plastids (Only in Plants)
Types:
Chloroplast – photosynthesis
Leucoplast – storage (starch, fats, proteins)
Chromoplast – pigments (fruits, flowers)