WEEK3 Flashcards
Macromolecules (25 cards)
What is a non-polar covalent bond?
Bonds formed between two non-metals with the same electronegativity value
what is a polar covalent bond?
bonds formed between elements with different electronegativity value, resulting in an electric dipole
what is an ionic bond?
when two atoms are so unequal in their attraction for valence electrons that the more electronegative atom strips an electron completely away from its partner
How are weak bonds important in biology?
many large biomolecules are held in their functional form by weak bonds
What are Van der Waals forces
these are attractions between molecules not caused by covalent bonds or ionic bonds, but rather by tiny fluctuations in the electron clouds surrounding the atom and molecules.
What are the types of Van der Waals forces?
-Dipole-Dipole Forces
-Hydrogen Bonding
-London Dispersion Force
What are London Dispersion forces?
London dispersion forces are caused by fluctuations in charge. sometimes electrons are concentrated more to one side of an atom or molecule, resulting in a temporary imbalance in charge, causing brief attractions.
Dipole-Dipole moment:
Some molecules have a permanent imbalance in charge, with one side being partially negative and the other side being partially positive, these are called dipole molecules. when they get together they attract.
What are hydrogen bonds?
when a hydrogen atom is covalently bonded to an electronegative atom, the hydrogen atom has a partial positive charge causing it to attract to nearby electronegative atoms. These bonds are relatively weak but are critical in stabilizing the structure of proteins, nucleic acids and macromolecules
What are some importance of Van der Waals forces?
-solubility
-biology and biochemistry
-Adhesion and cohesion
In the 1950s, two scientists recreated the conditions of early Earth and discovered that organic molecules formed spontaneously. What are the names of these scientists and what is the name of their experiment.
Stanley Miller and Harold Urey. Miller-Urey Experiment
What makes the water molecule polar?
The unequal sharing of charge and its V-like shape
How are water molecules held together?
Hydrogen Bonds
The extraordinary properties of water are emergent properties resulting from?
Hydrogen bonding
What are the four emergent properties of water that contribute to earths suitability for life?
- Cohesive/adhesive behavior
- ability to moderate temperature
- expansion upon freezing
- versatility as a solvent
What is the difference between cohesion and adhesion?
Cohesion- Water - water
Adhesion- water- other substances
what is surface tension?
it is the measure of how hard it is to stretch or break the surface of a liquid.
Pure water has a neutral pH of 7. where concentration of H+ equals that of OH-. Describe acidic and basic conditions.
Acidic conditions- Higher H+ conc.
Basic conditions- Higher OH- conc.
What is a buffer?
A system in dynamic equilibrium that maintains the pH of its surrounding.
What is an example of a buffer system?
Bicarbonate (HCO3-) in blood plasma resists changes in pH by absorbing or releasing H+ ions
How does Carbon enter the biosphere?
Through the action of photosynthetic plants that convert atmospheric carbon (CO2) into molecules of life, which is then taken in by plant-eating animals.
the four valence electrons of carbon can covalently bond to:
Oxygen, hydrogen, nitrogen,
What are functional groups?
components of biological molecules that are most commonly involved in chemical reactions
What are the 7 most important groups in biological processes?
- hydroxyl
- carbonyl
- carboxyl
- amino
- sulfhydryl
- phosphate
- methyl group
