BIO1011 Week 4: Building Life - Evolution of Complex Cells

These flashcards cover key vocabulary terms related to the study of eukaryotic and prokaryotic cells, their origins, and cellular structures as discussed in Week 4 of BIO1011.

Endomembrane System

A network of membranes within the cell, including the nuclear envelope, endoplasmic reticulum, Golgi apparatus, lysosomes, and plasma membrane, that compartmentalizes cell functions.

Endosymbiosis

A theory proposing that eukaryotic cells originated from prokaryotic organisms via symbiotic relationships. This process suggests that certain organelles, such as mitochondria and chloroplasts, were once free-living prokaryotes that entered into a mutually beneficial relationship with ancestral eukaryotic cells.

FECA (First Eukaryotic Common Ancestor)

The earliest common ancestor of all eukaryotic cells.

It is characterized by having complex cellular structures, such as a defined nucleus and membrane-bound organelles, which differentiate eukaryotes from prokaryotes.

LECA (Last Eukaryotic Common Ancestor)

The most recent ancestor of all current eukaryotic cells.

LECA is a critical concept in evolutionary biology as it serves as the lineage from which all modern eukaryotes have diverged, including animals, plants, fungi, and protists.

Compartmentalisation

The division of a cell into separate compartments, each with specific functions, to increase efficiency.

Mitochondria

Mitochondria are double-membrane-bound organelles often referred to as the 'powerhouses of the cell' due to their essential role in energy production through the process of aerobic respiration.

Mitochondria generate adenosine triphosphate (ATP), the primary energy currency of the cell.

Their structure is specialised, featuring an outer membrane that contains porins for molecule passage and an inner membrane that is highly folded into cristae to increase surface area for reactions.

Additionally, mitochondria possess their own circular DNA (mtDNA) and ribosomes, indicating a unique evolutionary history linked to the endosymbiotic theory,

Chloroplast

Organelles found in plant cells that conduct photosynthesis, which converts light energy into chemical energy stored in glucose.

These double-membrane-bound organelles contain chlorophyll, the green pigment responsible for capturing sunlight

The structure of chloroplasts includes an outer membrane, an inner membrane, and an intricate system of thylakoid membranes stacked into structures called grana, which are suspended in a fluid matrix known as the stroma.

Cyanobacteria

Photosynthetic bacteria believed to be ancestors of chloroplasts through endosymbiosis.