cell structure and function

Cell Theory

States that all living organisms are composed of cells, which are the smallest functioning units of life and arise from pre-existing cells.

Prokaryotes

Simple cells lacking a nuclear membrane, membrane-bound organelles, and with a basic internal structure; typically unicellular.

Eukaryotes

Cells with a nucleus, membrane-bound organelles, complex internal structure, and can be multicellular; appeared around 1 billion years ago.

Membrane-bound Organelles

Small compartments within cells surrounded by a membrane, aiding in protection and efficient task execution, commonly found in eukaryotes.

Importance of Small Cells

Cells are small to maximize their surface area to volume ratio for efficient diffusion of substances in and out of the cell.

High SA:V Ratio

Enables rapid diffusion of substances in and out of cells, crucial for cell survival and function.

Unique Plant Cell Organelles

Chloroplasts, cell wall, and large vacuole.

Unique Animal Cell Organelles

Lysosomes and flagella.

Types of Organelles

Various structures within cells with specific functions such as plasma membrane, cell wall, cytoplasm, nucleus, rough ER, smooth ER, Golgi apparatus, mitochondria, chloroplasts, lysosomes, vacuoles, and flagella.

Origin of Mitochondria

Mitochondria likely originated from prokaryotic cells that were engulfed by eukaryotic cells, forming a symbiotic relationship for energy production.

Fluid Mosaic Model

Describes cell membrane structure as a fluid phospholipid bilayer with embedded proteins and molecules, allowing flexibility and selective permeability.