Prof White Flashcards
What problem was caused by Cyanobacteria beginning to photosynthesise?
An oxygen crisis where there was large amounts of O2, creating a problem for anaerobic life.
Name the 7 requirements for life.
Liquid water, energy source, building blocks, biosynthetic pathways, separation from environment, genetic code & natural selection.
Name 4 key steps towards life.
Formation of monomers, synthesis of polymers, self replicators & evolution + selection.
What is the suggestion of the abiotic synthesis of complex organic molecules by lightning-atmosphere reactions in hydrothermal systems?
The Miller-Urey hypothesis
What is the “Hot Sulfur” theory?
The theory that life first evolved deep in the ocean at high temperatures, potentially as thermophiles in black smokers.
How does RNA solve the DNA and protein paradox?
RNA can both store information and act as a catalyst.
What were the advantages of proteins taking over catalysis from ribozymes?
Proteins have more functional groups, are more stable and act as better catalysts.
Which enzyme was required to catalyse the evolution of RNA into U-DNA?
Ribonuclease reductase (RNR)
Which enzyme was required to catalyse the evolution of U-DNA into T-DNA?
Thydimylate synthase
What is LUCA?
Last Universal Cellular Ancestor
2 massive transfer events from bacteria to eukaryotes lead to the evolution of which organelles?
Chlorplast and Mitochondrian.
What 2 behaviours cause increased spread of bacteria?
Antibiotic overuse & global travel.
Which genes are essential?
Genes for glycolysis, ATP synthesis, DNA replication, transcription, translation and other unknown functions.
Halophiles and methanogens are examples of what type of archea?
Euryarchea
Acidophiles are examples of what type of archea?
Crenarchea
Name an enzyme which existed in LUCA and exists similarly in all domains of life.
RNA polymerase
What endosymbiosis event is proposed to have kick started the eukarya?
The capture of a proteobacterium which became the mitochondrion.
Which group of archea can live without oxygen?
Methanogens
What conditions do halophiles live in?
Saturated salt.
Which group of archea are essential in carbon and nitrogen cycles?
Thaumarchea
What conditions do hyperthemophiles live in?
High temperatures.
What are the results when the ‘Miller experiment’ is tested?
Many key building blocks are produced, included 17/20 amino acids.
Which theory suggests life came from outer space, most likely Mars?
Panspermia
Which theory suggests life came from early earth with only building blocks and energy sources?
Darwin’s ‘Warm little pond’
Which forms of life use RNA and U-DNA?
Some viruses
Why are eukarya thought to have arisen from the TACK superphylum?
Many eukaryal proteins (ribosomal, actin, etc) are found in TACK family members.
What makes archael membranes unique?
The use of isoprene chains, L-glycerol and ether linkage.
Why is methanogenesis so important?
It allows animals to generate energy from very low energy food.
What gives halophiles their red colour?
The bacteriorhodopsin in their membranes.
What is the internal pH of acidophiles?
6
