L1: Water, carbon and functional groups. Flashcards
(52 cards)
What is hydrogen bonding?
An intermolecular force seen in biological organisms. H is bonded with N, O, or F and must include at least 1 H. The + dipole formed by hydrogen attarcts the - dipole of the other molecule.
Why does water have special properties?
Hydrogen bonds take a lot of energy to make, hense why water has special properties.
“Inter” vs “Intra”
Inter = in between
Intrea = within
What are the four properties of water?
1) Density
2) Cohesion and Adhesion
3) Heat Capacity
4) Solubility
Density - When is water most dense?
Water is the only substance on the planet known to be less dense as a solid than a liquid.
Density - Why is ice less dense than water?
When the molec bonds together and freezes, there is air between the molecules and air has a lower density than water.
Density - Why is it benifical for ice to be less dense than water?
All life forms started from the water. If ice was more dense, as it would freeze it would sink in lakes and crush all living organisms, causing no life on the planet.
Density - What tempeture is water most dense at?
4 degrees C
Cohesion and Adhesion - What is cohesion?
Water molecules sticking together. Ex. Like linking arms with the person beside you
Cohesion and Adhesion - What is adhesion?
Water sticking to other polar substances. Ex. Linking arms with the perosn beside you and touching the wall.
Cohesion and Adhesion - How are plants benifited?
By water staying together (cohesion), plants can drag water up the stems of their structure.
Cohesion and Adhesion - What is a real world application?
Cohesion and adhesion account to why plane crashes into the water are fatal. The water bonds together making the plane hititng water simular to hitting concreate.
Heat Capacity - what kind of heat capacity does water have?
Due to its strong polarity of the molecule, it takes alot of heat to seperate intermolecular bonds. Water has the capacity to absorb lots of energy (why Mr. Wang wet his hand before setting it on fire - water absorbed heat).
Solubility - how soluable is water?
Water is considered the universal substance as it is has a high soluability. Water disolves ionic and polar compounds by “surronding”/interacting with ions or molecules - this is due to waters polarity.
Solubility - hydrophillic vs hydrophobic.
Hydrophillic (water loivng) - compounds that interact with water (polar molec and ions)
Hydrophobic (water fearing) - compounts that dont interat with water (non-polar molecules - such as fat)
Solubility - can cells have hydrophillic and hydrophobic compoents?
YES. Many biologically acitve molecules have hydrophillic and hydrophobic compnents. Phosphilipid’s found in cell membranes have hydrophillic heads and two hydrophobic tails.
What makes an acid?
If [H3O2+] > [OH-], then solutions are acidic (low pH).
What makes a base?
If [H3O2+] < [OH-], then solutions are basic (high pH).
What makes somethign neutral?
If [H3O2+] = [OH-], then solutions are neutral (pH 7).
Examples of acids, bases, and neutral substances
Acid - Coffee, lemon juice, vinegar
Base - soap, bleach, baking soda
Neutral - Distilled water
What is the backbone of biochemistry?
Carbon
What are hydrocarbons?
C & H bonded together (non-polar)
Explain uses of carbon
Graphite (in pencils) is pure carbon. Anything carbon based can form diamonds.
Explain the structure and behaviors of carbon.
Carbon has 4 valence e-, allowing for 4 covalent bonds and can branch in a variety of directions. Carbon can make rings, branches or chains, and single, double, or tripple bonds. Carbon commonly bonds with H, N, O, S and P.
