ALMA D'ARTE

Alma d' Arte Biology


  • Home
  • Assignments
  • Syllabus
  • Resources

9/9/2019

Ancient Organisms

0 Comments

Read Now
 

How do we know how old things are?


Radiometric Dating: The use of radioactive isotopes as a
                                     measure for determining the age of a rock or fossil


Radioactive isotope: an unstable form of an element that decays
                                     into another element by radiation, that is, by
                                     emitting energetic particles


Half-Life: the amount of time it takes for one half of a substance to decay

Uranium-238: has a half life of 4.5 billion years

Potassium-40: has a half life of 1.3 billion years

Stromatolites: are about 3.5 billion years old, calcareous mound built up
                          of layers of lime-secreting cyanobacteria and trapped
                          sediment, found in Precambrian rocks as the earliest known
                          fossils, and still being formed in lagoons in Australasia.

Prokaryotes: about 3.5 billion years ago, a microscopic single-celled 
                        organism that has neither a distinct nucleus with a
                        membrane nor other specialized organelles.


Prokaryotes include the bacteria and cyanobacteria.
​

Picture
  • Unicellular organism who lacks membrane bound organelles
  • DNA not in a nucleus, it just floats around in cytoplasm
  • much smaller than eukaryotic cells
  • a prokaryote is about the size of a mitochondria in a eukaryote 
  • single DNA loops

Bacteria and Archaea are prokaryotes, the two domains of prokaryotic life.

​

Types of Bacteria


  • Cyanobacteria are a phylum of bacteria that obtain their energy through photosynthesis and are the only photosynthetic prokaryotes able to produce oxygen.

  • Round bacteria are referred to as cocci (singular: coccus),
    • an example is Streptococcus
 
  • ​Cylindrical, capsule-shaped bacteria are named bacilli (singular: bacillus),
    • bacteria that make yogurt: Lactobacillus bulgaricus 
​
  • Spiral bacteria are called spirilla (singular: spirillum)
    • ​Lyme disease and syphillis are caused by this type of bacteria​​

Picture

  • Flagella: whip-like appendages used to move around, like arms

  • Pili: short, hair-like appendages extending from the surface, used to stick to surfaces

  • Capsule: sticky coating, used to stick to surfaces

Cyanobacteria in Fossils



https://www.smithsonianmag.com
​
Picture

https://sciencestruck.com/what-are-stromatolites-how-do-they-form


Pathogenic Bacteria?


Some but not all bacteria are pathogens: a disease causing agent

Some bacteria are purely beneficial and help with symbiosis: the relationship in which two different organisms live together, often interdependently. 

Nitrogen Fixation:


  • Converting atmospheric nitrogen into a form that plants can use to grow
    • ​Two types of bacteria do this job: non-symbiotic bacteria in the soil and symbiotic bacteria that live in the roots of plants.
    • Bacteria in the genera Clostridium and Azotobacter are non-symbiotic nitrogen-fixing bacteria.
    • The genus Rhizobium are symbiotic bacteria.
​
Picture

Cell Division in Bacteria is Called Binary Fission


Picture
https://simple.wikipedia.org/wiki/Binary_fission

Archaea


The other domain of prokaryotic life, tend to live in extreme environments

Grouped according to where they live (pg 371):
​
  • Halophiles: live in very salty places
  • Hyperthermophile: extremely high temperatures (80 to 100 Celcius), (176 to 212 Fahrenheitt) ​
Picture

​Archaea in hydrothermal vents:


The sea floor is an anaerobic environment, no oxygen


  • Serpentinization: H2, hydrogen is formed when mantle rock is exposed to seawater, the rock columns that are formed as gases emerge from the earth's crust in hydrothermal chimneys
​
  • Methanogens: archaea that produce methane as a by-product of converting energy from carbon dioxde, using hydrogen H2 as an energy source
  
  • Anaerobic Archaea: eat methane

​

The beginnings of life in hydrothermal vent



The heated fluids rise back to the surface through openings in the seafloor. Hydrothermal fluid temperatures can reach 400°C (750°F) or more, but they do not boil under the extreme pressure of the deep ocean.

As they pour out of a vent, the fluids encounter cold, oxygenated seawater, causing another, more rapid series of chemical reactions to occur. Sulfur and other materials precipitate, or come out of solution, to form metal-rich towers and deposits of minerals on the seafloor. 
​

https://www.whoi.edu/know-your-ocean/ocean-topics/seafloor
​

Deep Sea Research Affects Engineering today:

https://www.reuters.com/article/us-norway-deep-sea-minerals/

https://www.theguardian.com/environment/2010/aug/31/greenland-greenpeace-arctic-oil-rig


Life in Hydrothermal Vents



Endosymbiotic Theory 


Evolutionary theory of the origin of eukaryotic cells from prokaryotic organisms.

That prokaryotes ate a mitochondria and kept it around, some ate a chloroplast and became plants (pg. 391)


Endosymbiotic theory deals with the origins of mitochondria and chloroplasts, two eukaryotic organelles that have bacteria characteristics. Mitochondria and chloroplasts are believed to have developed from symbiotic bacteria, specifically alpha-proteobacteria and cyanobacteria, respectively.
​
Picture

​Mitochondria: an organelle found in large numbers in most cells, in which the biochemical processes of respiration and energy production occur. It has a double membrane, the inner layer being folded inward to form layers (cristae).

Makes 
ATP

Mitochondria origin: The endosymbiotic hypothesis for the origin of mitochondria (and chloroplasts) suggests that mitochondria are descended from specialized bacteria (probably purple nonsulfur bacteria) that somehow survived endocytosis by another species of prokaryote or some other cell type, and became incorporated into the cytoplasm.

SO Mitochondria and Chloroplasts were bacteria billions of years ago.

They have their own DNA 


Mitochondria and chloroplasts have striking similarities to bacteria cells.
  • They have their own DNA, which is separate from the DNA found in the nucleus of the cell.
  • And both organelles use their DNA to produce many proteins and enzymes required for their function.

Mitochondrial DNA (mtDNA or mDNA): is the DNA located in mitochondria, cellular organelles within eukaryotic cells that convert chemical energy from food into a form that cells can use, adenosine triphosphate (ATP).

Mitochondrial DNA is double-stranded like cellular DNA in prokaryotes. However it is circular and similar in size and structure to the single DNA loops found in prokaryotes like bacteria.
Mitochondria and Chloroplasts can no longer live outside the eukaryotic cell, and cells cannot live without mitochondria or chloroplasts because that is how they get ATP.

Over millions of years of evolution, mitochondria and chloroplasts have become more specialized and today they cannot live outside the cell.

They are now interdependent/codependent  


Cells would only be able to obtain energy from anaerobic respiration (in the absence of oxygen)

So mitochondria helped get archaea out of the hydrothermal vents

Evidence obtained so far indicates that the Bacteria and Archaea diverged from a common ancestor about 
3.7 billion years ago, and somewhat later the Archaea diverged from the lineage that would become the Eukarya.
​
  • Evidence was found by comparing nucleic acid sequences to discover the evolutionary relationships among microorganisms.
  • The more alike the rRNA sequences were between two microbes, the more recently they shared an ancestor.
  • Read more: 
  • http://www.biologyreference.com/ArBi/Archaea.html#ixzz5cZWeYzkr

Around 2 billion years ago, archaea and bacteria found a way to share genes or merge some of their material and a third kingdom of life, eukaryotes, was born.

Mitochondria know both aerobic and anaerobic respiration: When oxygen is present, the mitochondria will undergo aerobic respiration which leads to the Krebs cycle.
  • However, if oxygen is not present, fermentation of the pyruvate molecule will occur.

Eukaryote


  • An organism consisting of a cell or cells in which the genetic material is DNA in the form of chromosomes contained within a distinct nucleus.
  • Eukaryotes include all living organisms other than the eubacteria and archaebacteria.
​
Picture

Bacterial Behavior



How we Get Cobalt for RECHARGEABLE Batteries Now



​https://www.theguardian.com/global-development

Other Options:

https://www.azomining.com/Article.aspx?ArticleID=1438


Look out for cobalt free items


Graphene Solar Panels

​Support companies that want Graphene: 

https://www.graphene-info.com/graphene-investing

Picture
https://biovolttechblog.com/2018/05/04/graphene-the-future-is-here/
​


Learning about Exremeophiles can help us get clues about life on other planets


https://www.cnet.com/news/water-found-at-potentially-habitable-planet-possible-this-is-a-water-world/

Share

0 Comments



Leave a Reply.

Details

    Author: Jazmin Gannon

    A place to grow

    Archives

    April 2021
    March 2021
    February 2021
    January 2021
    December 2020
    November 2020
    October 2020
    September 2020
    August 2020
    July 2020
    May 2020
    April 2020
    March 2020
    February 2020
    January 2020
    December 2019
    November 2019
    October 2019
    September 2019
    August 2019
    July 2019
    May 2019
    April 2019
    March 2019
    February 2019
    January 2019
    December 2018
    November 2018
    October 2018
    September 2018
    August 2018
    July 2015

    Categories

    All

    RSS Feed

Powered by Create your own unique website with customizable templates.
  • Home
  • Assignments
  • Syllabus
  • Resources