bio

Cell Theory

All living things are made of cells; Cells are the basic units of structure and function in living organisms; All cells come from pre-existing cells.

Matthias Schleiden

Scientist who stated that all plants are made of cells (1838).

Theodor Schwann

Scientist who expanded the idea of cell theory to include all animals being made of cells (1839).

Rudolf Virchow

Scientist who concluded that all cells arise from pre-existing cells, completing the cell theory (1855).

Prokaryotic Cells

Simpler, unicellular organisms with no nucleus, smaller size, and contain bacteria and archaea.

Eukaryotic Cells

Complex multicellular organisms with a nucleus and membrane-bound organelles, including animals, plants, fungi, and protists.

Animal Cells vs. Plant Cells

Animal cells lack a cell wall and chloroplasts, while plant cells have both and are typically rectangular with large central vacuoles.

Essential components of eukaryotic cells

Mitochondria, cell membrane, nucleus, cytoplasm, nucleolus, ribosome, vacuole/vesicle, Golgi body, cytoskeleton, lysosome, endoplasmic reticulum.

Endosymbiotic Theory

Theory suggesting that chloroplasts and mitochondria originated from ancient bacteria engulfed by primitive eukaryotic cells.

Fluid Mosaic Model

Model describing the structure of the cell membrane, composed of a phospholipid bilayer, proteins, cholesterol, and carbohydrates.

Passive Transport

The movement of materials across a cell membrane without the use of energy, usually down the concentration gradient.

Active Transport

The movement of materials against a concentration gradient, requiring energy.

Osmosis

Movement of water across a cell membrane from low to high solute concentration, aiming to balance water levels.

Hypotonic Solution

Solution with lower solute concentration outside the cell; water enters the cell, possibly causing it to swell or burst.

Hypertonic Solution

Solution with higher solute concentration outside the cell; water leaves the cell, causing it to shrink.

Isotonic Solution

Solution with equal solute concentration inside and outside the cell; water moves equally in both directions.

Impact on Animal Cells in Hypotonic Solution

Animal cells swell and may burst due to water influx.

Impact on Plant Cells in Hypotonic Solution

Plant cells become turgid due to water entering, which is generally beneficial.

Impact on Animal Cells in Hypertonic Solution

Animal cells shrink (crenation) due to water leaving.

Impact on Plant Cells in Hypertonic Solution

Plant cells undergo plasmolysis as water exits, leading to wilting.

Exocytosis

Process that moves materials out of the cell via vesicles fusing with the cell membrane.

Endocytosis

Process that brings materials into the cell by engulfing external substances to form vesicles.