Lecture 1: Intro to Cell Biology Flashcards
What is cell biology?
the study of cellular structure, function and behaviours of cells
How are eukaryotes classed as chimeras?
They share an ancestor that loosed a bacteria, endosymbiont that evolved into modern mitochondria.
Additional bacterial and eukaryotic cell endosymbionts evolved into modern chloroplasts/plastids.
What is the Archezoa hypothesis?
Has 2 phases.
- Suggests a plasma membrane of an ancient prokaryotic cell invaginated and gave rise to a first set of endomembrane, nucleus and RER.
- Involved one cell eating another one (phagocytosis)
- one group of alpha-proteobacteria got engulfed and became the now known mitochondria
How is DNA stored in the mitochondria?
Circular chromosome where there are ~16000base pairs which encode a small collection of genes.
The 12S gene is the homologue of a small subunit rRNA gene
What did a primary plastid evolve into?
Modern chloroplast
Are nucleus and RER of endo- or exogenous origin?
Endogenous
Are mitochondria and chloroplasts of endo- or exogenous origin?
Exogenous
What do all cells have?
plasma membrane
What does the plasma membrane do?
Separates internal and external environments, enclosing the cell content. It allows different concentrations of substances to be obtained.
What are internal membranes in eukaryotes called?
Endomembranes
What do endomembranes do?
Allow separate compartments (organelles) to have different constituents and functions.
What are the major components of cellular membranes?
Lipid bilayer with proteins scattered throughout.
Give some functions of the plasma membrane
Immediate communication with the environment and other cells.
Barriers functions - regulates molecules going in and out of the cell.
Cell growth - is able to change shape
