Module 1.2: Water - Properties, solubility, protein folding, pH Flashcards
PROPERTIES
Water is essential for life how?
OBJECTIVE 6
- Important biochemical reactions occur in aqu. env. in cell / body.
- Critical determinant in structure and function of biopolymers: proteins, protein folding, nucleic acids, phospholipids
PROPERTIES
4 Key Components
OBJECTIVE 6
- Water is chemically “sticky”
- Excellent solvent because its polar
- Moderates temperature
- Ice (solid water) floats
PROPERTIES
Water’s properties explained by:
OBJECTIVE 6
Water is POLAR and produces partial charges.
PROPERTIES
Cohesion
OBJECTIVE 5
Water molecules form hydrogen bonds with each other.
PROPERTIES
Adhesion
OBJECTIVE 5
Polarity allws water to attract other polar molecules.
PROPERTIES
Water’s stickiness is important for living creatures:
OBJECTIVE 6
Cohesion and adhesion allow the movement of water through the
vascular tissue of plants.
SOLUBILITY
Water is an excellent solvent for:
OBJECTIVE 6
CHARGED and POLAR substances
* Charged and polar protein parts
* Small alcohols
* Carbohydrates
SOLUBILITY
Water is a poor solvent for:
OBJECTIVE 6
NONPOLAR substances
* Non-polar gases
* Aromatic groups
* Long hydrocarbon chains
SOLUBILITY
Electrolytes
OBJECTIVE 6
Dissociated ions of ionic compounds in a solution.
* Essential for proper cellular function
SOLUBILITY
Large molecules (like proteins) solubility
If ionic and polar regions are present, can be soluble in water.
* Makes cellular biochemistry possible
PROTEIN FOLDING
Water and protein folding
OBJECTIVE 6
In an aqueous solution, macromolecules fold to protect the hydrophobic residues from interacting directly with water.
PROTEIN FOLDING
Location of polar and non-polar groups in protein folding
- Polar groups out
- Non-polar groups in
PROPERTIES
How does water moderate temperature?
OBJECTIVE 6
Hydrogen bonds stablize molecule.
* Changes of temperature require lots of energy.
* High Specific Heat Capacity
PROPERTIES
Specific Heat Capacity
Amount of energy that needs to be put into 1g of a compound or substance in order to increase its temperature by 1 degree.
PROPERTIES
Heat of Vaporization
OBJECTIVE 6
Quantity of heat that a liquid must absorb for 1g to be converted from liquid to gaseous state.
PROPERTIES
Evaporative Cooling
Evaporation of water causes remaining surface to cool.
PROPERTIES
Global Conveyer Belt Model
Ocean currents moderate global climate.
* Warm equatorial surface waters move north and sinks.
* Cold & deep high salinity currents return to surface and is warmed by solar radiation.
PROPERTIES
Solid Water floats because:
Hydrogen bonds help solid water float.
* Air pockets form between hydrogen bonds when stable
pH
Acids
OBJECTIVE 7
Molecules that can split apart in water and release hydrogen ions (H+).
pH
Bases
OBJECTIVE 7
Molecules that split apart in water and release hydroxide ions (OH-).
pH
Buffers
OBJECTIVE 7
Substances that resist extreme changes in pH.
* Take up excess hydrogen or hydroxide ions
