Cell structure Biology

Prokaryotic cell

Single-celled organism without a nucleus.

Eukaryotic cell

Organism with membrane-bound organelles and nucleus.

HeLa cells

Immortal cell line used in medical research.

Endosymbiotic theory

Mitochondria and chloroplasts originated from bacteria.

Active transport

Movement of molecules against concentration gradient, requiring energy.

Passive transport

Movement of molecules down concentration gradient, no energy needed.

Concentration gradient

Difference in concentration of a substance across space.

Osmosis

Diffusion of water across a selectively permeable membrane.

Aquaporin

Channel protein facilitating water transport in cells.

Transport protein

Protein that helps move substances across cell membranes.

Phagocytosis

Process of engulfing large particles or cells.

Hypotonic solution

Solution with lower solute concentration compared to cell.

Hypertonic solution

Solution with higher solute concentration compared to cell.

Isotonic solution

Solution with equal solute concentration to cell.

Central vacuole

Large organelle in plant cells for storage and support.

Ribosome

Molecular machine synthesizing proteins from amino acids.

Cell membrane

Phospholipid bilayer controlling entry and exit of substances.

Cell wall

Rigid outer layer providing structure to plant cells.

Cytoplasm

Gel-like substance where cellular processes occur.

Mitochondria

Organelles generating ATP through cellular respiration.

Chloroplast

Organelles in plant cells converting sunlight to energy.

Nucleus

Membrane-bound organelle containing genetic material.

Specialized cells

Cells adapted for specific functions in multicellular organisms.

Simple diffusion

Movement of small molecules directly through the membrane.

Facilitated diffusion

Transport of molecules via specific channel or carrier proteins.

Endocytosis

Process of taking substances into the cell via vesicles.

Exocytosis

Process of expelling substances from the cell via vesicles.

Plant cells in solution

Plant cells maintain rigid pressure in hypotonic solutions.

Animal cells in solution

Animal cells may burst in hypotonic solutions.

Solute

Substance dissolved in a solvent to form a solution.

Solvent

Substance that dissolves a solute, forming a solution.

Cholesterol

Essential fatty substance in cells for hormone production, vitamin D, and cell membrane integrity.