Biology - Cells

Prokaryotic Cells

Simple, unicellular organisms without a nucleus or membrane-bound organelles.

Eukaryotic Cells

Complex cells with a nucleus and membrane-bound organelles, can be unicellular or multicellular.

Bacteria

Prokaryotic cells that lack a nucleus and have a simple structure.

Animal Cells

Eukaryotic cells that lack a cell wall and chloroplasts, have a flexible plasma membrane.

Plant Cells

Eukaryotic cells with a rigid cell wall, chloroplasts for photosynthesis, and a central vacuole.

Cytosol

The fluid component of the cytoplasm where metabolic reactions occur, found in all cell types.

Cytoplasm

The entire contents within the plasma membrane excluding the nucleus, found in all cell types.

Nucleus

The organelle that contains genetic material (DNA) and controls cell activities, found in eukaryotic cells.

Ribosome

The site of protein synthesis, found in both prokaryotic and eukaryotic cells.

Rough Endoplasmic Reticulum

A network of membranes with ribosomes that synthesizes proteins, found in eukaryotic cells.

Smooth Endoplasmic Reticulum

A network of membranes without ribosomes that synthesizes lipids, found in eukaryotic cells.

Golgi Apparatus

The organelle that modifies, sorts, and packages proteins and lipids for secretion or use, found in eukaryotic cells.

Lysosome

An organelle containing digestive enzymes to break down waste, found in eukaryotic cells.

Mitochondria

The powerhouse of the cell that produces ATP through cellular respiration, found in eukaryotic cells.

Cell Wall

A rigid outer layer providing structure and protection, found in plant cells and some prokaryotes.

Chloroplast

The organelle that conducts photosynthesis, converting light energy into chemical energy, found in plant cells.

Plasma Membrane

A phospholipid bilayer that surrounds the cell, controlling the movement of substances in and out.

Central Vacuole

A large storage organelle in plant cells that maintains turgor pressure and stores nutrients.

Cilia/Flagella

Hair-like structures that aid in cell movement, found in some eukaryotic and prokaryotic cells.

Plasma Membrane Structure

Composed of a phospholipid bilayer with embedded proteins, cholesterol, and carbohydrates.

Movement of Material

The plasma membrane regulates the entry and exit of substances through passive and active transport.

Communication with Cells

The plasma membrane contains receptors that allow cells to communicate and respond to signals.

Maintenance of Fluidity

The plasma membrane's lipid composition and cholesterol content help maintain its fluidity.

Diffusion

The passive movement of molecules from an area of higher concentration to an area of lower concentration.

Concentration Gradient

The difference in concentration of a substance across a space, affecting molecular movement.

Permeable

A membrane that allows all substances to pass through freely.

Semi-permeable

A membrane that allows certain substances to pass while restricting others.

Passive Transport

The movement of substances across a membrane without energy input, including osmosis and diffusion.

Osmosis

The diffusion of water across a semi-permeable membrane from an area of low solute concentration to high.

Facilitated Diffusion

The process of passive transport of molecules across a membrane via specific proteins.

Active Transport

The movement of substances against their concentration gradient, requiring energy (ATP).

Exocytosis

The process of expelling materials from the cell via vesicles, necessary for secretion and waste removal.

Endocytosis

The process of taking in materials by engulfing them in a vesicle, necessary for nutrient uptake and cell signaling.