IB Biology A111 - The Origin of Life Lecture Notes

A set of vocabulary flashcards covering key concepts from the biology unit on the origin of life.

Cell Theory

1. all living things are made of cells,

2. cells are the basic unit of life

3. all cells come from pre-existing cells.

Abiogenesis

The creation of life from non-living material.

Panspermia

life arrived on Earth via comet or meteorites

Spontaneous Generation

life from non-living material, disproven by Pasteur's experiments.

Nutrient broth experiment

Pasteur's experiment, shows life does not form from non-living material.

Miller-Urey Experiment

experiment showed organic molecules can be created from inorganic compounds under prebiotic Earth conditions.

Vesicles

Water droplets enclosed in a membrane, formed from phospholipids, bilayer of cell membrane

Ribozyme

RNA enzyme that catalyzes a chemical reaction

Endosymbiosis

larger prokaryotes respire through endocytosis, lead to the making of mitochondria and chloroplasts.

Viruses

Nonliving, not in stable state, nongrowing, not made of cells, cannot replicate

Obligate Intracellular Parasites

must infect host cells to reproduce and survive.

Capsid

protein outer coat surrounding the genetic material of a virus.

Enveloped Virus

has an outer lipid membrane, from the host cell during budding

Non-enveloped Virus

A virus without a lipid bilayer

Prokaryotic Cells

Cells without a membrane-bound nucleus, decomposers, can cause disease

cell wall

protects cell, maintains shape, made of peptidoglycan

Microscope Types

Different instruments used to magnify specimens: Light microscopes, Electron Microscope such as Transmission and Scanning Electron Microscopes.

High and low resolution

100x, 400x

Catalysis

to give control over when reactions occur

Self-Assembly

carbon compounds

Compartmentalization

a membrane must develop to enclose cell contents

Self-Replication

molecules make copies of themselves

Budding

process where enveloped viruses leave a host cell

Types of Microscopes

TEM and SEM

Cell Membrane Function

Determines what can enter the cell

Pilus Function

exchange of genetic material during reproduction

Capsule Role

Protects bacterium

Ribosome Size in Prokaryotes

Prokaryotic 70S

Mesosome Function

respiration and DNA replication

Nucleus

holds cell's genetic material and controls cellular activities

Mitochondria

The powerhouse of the cell, supplies energy for cellular functions

Ribosomes

synthesize proteins

Golgi Apparatus

packages proteins and lipids

Lysosomes

break down waste materials

Thermal vents

life began from ancient underwater vents

Chloroplasts

plant cells, for photosynthesis

Cytoplasm

jelly-like substance, holds organelles in place

Plasma Membrane

composed of a lipid bilayer, regulating entry and exit

Centrioles

involved in cell division and the formation of spindle fibers, animal cell’s only

Cytoskeleton

protein filaments and tubules, provide structural support

Vacuoles

sacs that store nutrients, waste products, and water; larger in plant cells.

Smooth Endoplasmic Reticulum (Smooth ER)

involved in lipid and steroid production

Rough Endoplasmic Reticulum (Rough ER)

studded with ribosomes, synthesizes and processes protein

Nucleolus

dense region in nucleus where ribosomes are made

Chlorophyll

located in chloroplasts captures light energy for photosynthesis

Tidal Pools

life arose in tidal poos on primeval Earth

Required Developments for the origin of cell

catalysis, self-assembly, compartmentalization, self-replication

2 domains of prokaryotes

Archaebacteria, Eubacteria

Shape of bacteria

Bacillus, Coccus, Spirilla