Bio Concept 1 Flashcards
List the features common to all lifeforms
- Made of common set of chemical compounds (carbs, fatty acids, nucleic acids & amino acids)
- Made of cells
- Use environmental molecules to create new molecules
- Take energy in from environment
- Regulate internal environment
- Contain genetic info for development, maintenance, function and reproduction
- Use universal molecular code to build proteins
- Exist in populations that evolve over time
List the benefits and costs of viruses.
Benefits:
Asexual reproduction
Contain genetic information
Population evolves over time
Costs:
Dependent on host for reproduction
Not comprised of cells
What forces created life on earth? Explain different hypotheses for life formation on Earth.
The primordial ‘soup’ of early earth was a reducing environment, which facilitated organic molecule formation, such as DNA bases.
Extra-terrestrial – life was brought to earth from another planet or comet.
Discuss how Stromatolites (often referred to as “living fossils”) provide evidence for the beginning of life on Earth.
Because water is trapped between the limestone layers, which also traps any organisms within the water, causing them to become encased and fossilized. These organisms can then be dated, which examples in Greenland were, and found to be around 3.7 billion years old, giving strong evidence for when life arose on earth.
List the properties of water which are critical to the chemistry of life.
Water molecules are able to interact with each other through hydrogen bonding (very strong intermolecular force)
Water has high specific heat (4.186J g^-1 degrees C^-1)
Has a high melting and boiling point (0 and 100 degrees respectively)
High heat of vaporization
Cohesion (H+ bonding between H2O molecules)
Adhesion (attraction of water to other molecules)
Explain how the structure of water supports life for each of the following properties of water:
* Cohesion of water molecules
* Moderation of temperature
* Floating of ice
* The solvent of life
Cohesion: allows for processes such as water flow from the roots of a tree to the leaves without using any energy (passive process)
Moderation of temperature: Evaporation has a cooling effect on the environment, as lots of heat from the sun is absorbed by the oceans, keeping the earth and land cool.
a strong lattice with hydrogen bonds, but has gaps within it, meaning solid water is less dense than liquid water, which is why ice floats. If ice was not like this, then bodies of water would freeze from the bottom up, killing anything that lived inside it.
Solvent of life: Can have both hydrophobic and hydrophilic reactions (also can act as a weak acid or weak base)
Above is an image of the major elements of organic molecules. Discuss why are they called major elements?
They are referred to as major elements because of both the amount found within the body, and the essential functions they carry out.
Carbon is the basic building block of life. Explain why.
Because it is capable of forming multiple covalent bond types simultaneously (4 single bonds, or 2 single and 1 double, or 2 double bonds or 1 single and 1 triple bond).
