Astrobiology and the Search for Extra Terrestrial Life
The University of Edinburgh
Lecture Summary: The Structure of Life
The Structure of Life: Building Blocks
The fundamental elements that make up most of the compounds from which life is constructed:
- Carbon
- Hydrogen
- Nitrogen
- Oxygen
- Phosphorus
- Sulphur
Other elements:
- Iron
→ Red blood cells
- Calcium
→ Forms phosphate structures that are part of all skeletons
Example: Glycine
- An amino acid
- Made up of 2 carbon atoms, nitrogen,
some hydrogen and oxygen
→ Also conforms to the idea of
CHNOPS
- Carbon is the backbone of the molecule
About Amino Acids
- Amino acids linked in a long chain makes up a protein
- Can bind to other chains
- Can fold up in particular shapes
- Forms the complex diversity of complex molecules that make up life
- Amino acids are essential as building blocks for constructing the proteins in our cells
, Life needs other molecules as well, like sugars and water.
About Sugar
- Has ring-like structure called adenine
- Fine carbons form the ring around an
oxygen atom
- Various other atoms attach to that ring of
carbon atoms
- Can be strung together to create long,
complex chains of sugars
→ This is how we end up with complex
carbohydrates in our food
About Adenine
- Can be transformed by adding a reverse sugar structure to make adenosine
About Adenosine
- Can add phosphorus and oxygen atoms
- Oxygen atoms gives phosphate molecules as phosphate groups
- This creates adenosine triphosphate
About Adenosine Triphosphate
- Forms a component of deoxyribonucleic acid (DNA) IF strung together with other
molecules
These biosynthesis reactions occur within the cells of all organisms on Earth.
Water
- Water is the solvent in which these chemical reactions can occur
→ We need a liquid in order for molecules to move around
We refer to life on Earth as being carbon-based and water-based because the molecules
from which humans are constructed have carbon as their backbone, and water is required
in order for the necessary chemical reactions to occur within our cells.
The University of Edinburgh
Lecture Summary: The Structure of Life
The Structure of Life: Building Blocks
The fundamental elements that make up most of the compounds from which life is constructed:
- Carbon
- Hydrogen
- Nitrogen
- Oxygen
- Phosphorus
- Sulphur
Other elements:
- Iron
→ Red blood cells
- Calcium
→ Forms phosphate structures that are part of all skeletons
Example: Glycine
- An amino acid
- Made up of 2 carbon atoms, nitrogen,
some hydrogen and oxygen
→ Also conforms to the idea of
CHNOPS
- Carbon is the backbone of the molecule
About Amino Acids
- Amino acids linked in a long chain makes up a protein
- Can bind to other chains
- Can fold up in particular shapes
- Forms the complex diversity of complex molecules that make up life
- Amino acids are essential as building blocks for constructing the proteins in our cells
, Life needs other molecules as well, like sugars and water.
About Sugar
- Has ring-like structure called adenine
- Fine carbons form the ring around an
oxygen atom
- Various other atoms attach to that ring of
carbon atoms
- Can be strung together to create long,
complex chains of sugars
→ This is how we end up with complex
carbohydrates in our food
About Adenine
- Can be transformed by adding a reverse sugar structure to make adenosine
About Adenosine
- Can add phosphorus and oxygen atoms
- Oxygen atoms gives phosphate molecules as phosphate groups
- This creates adenosine triphosphate
About Adenosine Triphosphate
- Forms a component of deoxyribonucleic acid (DNA) IF strung together with other
molecules
These biosynthesis reactions occur within the cells of all organisms on Earth.
Water
- Water is the solvent in which these chemical reactions can occur
→ We need a liquid in order for molecules to move around
We refer to life on Earth as being carbon-based and water-based because the molecules
from which humans are constructed have carbon as their backbone, and water is required
in order for the necessary chemical reactions to occur within our cells.
