Mitochondria Flashcards
What types of lifeforms combined via endosymbiosis to eventually give rise to mitochondria?
free-living aerobic heterotrophic prokaryotic bacteria was engulfed by an anaerobic archaea
Mitochondria are often ___ like organelles located in the cells of almost all _______
rod, eukaryotes
What is one eukaryote that does not have mitochondria?
monocercomonoides
Why do people believe mitochondria originated from bacteria?
The little amount of DNA they contains is most likely bacterial DNA
What does sequencing of numerous mitochondrial DNA confirm?
- All mitochondria originated from the integration of a eubacterial ancestor into a host cell related to asgard archaea
- The transition to permanent organelles entailed a massive number of evolutionary changes
- The above changes occurred incrementally as the endosymbiont and the host became integrated
What is symbiosis?
A typically advantageous interaction between two different organisms living in close physical association
How is the archaea and bacteria merging symbiotic?
The archaea was anaerobe. By combining with aerobic bacteria, it can do respiration
Bacteria gained protection by living inside archaea
Describe how the DNA of the bacteria and archaea merged gradually over time
Each prokaryote has its own set of DNA (a genome). The bacteria’s genome remains
separate (curved blue line) from the archaea’s genome (curved purple line). The bacteria
continued to replicate within the host cell. Over time, during errors of replication or
perhaps when the bacteria lyses and loses its membrane separation from the host, genetic
material becomes separated and merges with the host cell genome. Eventually, the host
genome becomes a mixture of both genomes, and it ultimately becomes enclosed in an
endomembrane, a membrane within the cell that creates a separate compartment. This
compartment eventually evolves into a nucleus.
What are the 4 benefits of the bacteria merging into the archaea?
- Extra energy allowed archaea to focus on other things, like membrane bound organelles and a nuclear envelope
- Specialized functionality for each organelle
- Mitochondrial division occurred, merging some of it’s DNA into the eukaryotic cell
- Evolution of the nucleus
What are nuclear pores? What do they do?
They are tiny pores in the nuclear envelope. They selectively permit certain macromolecules to enter and leave the nucleus, including RNA
Why are eukaryotic cells able to more intricately regulate protein production?
The separation of the DNA from the protein synthesis
How to prokaryotic cells multiply?
Binary fission process, since they don’t have a nucleus. It’s fast and hard to control, which is problematic when a cell forms part of a larger organism
What happens when cell replication coordination fails in a multicellular organism?
cancer
Cellular respiration gives around __ ATP per glucose molecule while fermentation gives _ ATP
30, 2
What is an autotroph and heterotroph?
Autotroph: Organism that makes complex org compounds using carbon from substances such as CO2. generally uses light or inorganic chemical reactions
Heterotroph: Organism that cannot produce its own food and consumes autotrophs
What’s the 2nd law of thermodynamics?
In a closed system of reactions, entropy increases. Energy is always lost as heat in a reaction
What prevents the universe to disintegrate?
Influx of energy from the sun.
