A2.1 HL Origin of Cells

Prebiotic

a type of dietary fiber that feeds the beneficial gut bacteria, supporting digestive health

Organic compound

chemical compounds that contain carbon atoms bonded to hydrogen, often along with other elements like oxygen, nitrogen, and sulfur, forming the basis of all living organisms.

Spontaneous Generation

the outdated and disproven theory that life can arise spontaneously from non-living matter, such as the idea that maggots could emerge from rotting meats.

LUCA (Last Universal Common Ancestor)

the most recent common ancestor of all living organization from which the 3 domains of life

Domains

the highest taxonomic rank in biological classification, grouping all life forms into 3 categories

Eubacteria

simply known as bacteria, are a large group of single-celled organisms that have a simple cell structure without a nucleus, characterized by a rigid cell wall.

Archaea

are a group of single-celled microorganisms that are similar to bacteria but have distinct genetic and biochemical characteristics. They often thrive in extreme environments, such as hot springs, salt lakes, and deep-sea hydrothermal vents.

Eukarya

includes all organisms with complex cells containing a nucleus and other membrane - bound organelles, such as animals, plants, fungi, and protists.

Evolution

the process by which species change over time through genetic variation and natural selection.

Amphipathic

refers to a molecule that has both hydrophilic (water-loving) and hydrophobic (water-fearing) parts.

Hydrophilic (water-loving)

describes molecules or parts of molecules that are attracted to and can interact well with water. These substances dissolve in water.

Hydrophobic (water-fearing)

describes molecules or parts of molecules that repel water and do not mix well with it. These substances usually do not dissolve together in water.

Vesicle

A small, membrane-bound sac in a cell that transports and stores substances.

Ribozyme

an RNA molecule that acts as a catalyst for chemical reactions.

Hydrothermal vent

a fissure on the ocean floor that emits hot, mineral-rich water.

Thermophiles

organisms that thrive in extremely hot environments, often above 45 degree C.

Cyanobacteria

a group of photosynthetic bacteria that can produce their own food using sunlight and release oxygen as a byproduct, often found in water and soil environments.