L1: Water, carbon and functional groups. Flashcards
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.
What are structural isomers?
Isomers that differ in covalent arrangement of their atoms. # of possible isomers increases as C skeleton size increases. Structural isomers have the same chemical formula but a different shape causing different properties.
What are geometric isomers?
Isomers which share the same covalent partnerships but differ their spatial arrangements. Results from the fact that double bonds wont allow the atoms they join to rotate freely about the axis of the bond. Same chemcial formualr, subtle differences between isomers affect their biological activity.
What are isomers
Each of two or more compounds with the same formula but a different arrangement of atoms in the molecule and different properties.
What are functional groups?
Specific groupings of atoms within molecules that have their own characteristic properties
What are the improtance of functional groups?
Contritbute to molecular diversity by giving a molecule unique properties (physical and chemical). Ex. estradoil vs testosterone
How are functional groups formed
Atoms are bonded together on one end of a molecule giving it unique properties
How are functional gorups bonded
Usually a ionic/polar compound to a hydrogrem chain
What are ionic and polar molecules attracted to
Ionic/polar molecs are attarcated to other ionic/polar molecules (like attracts like)
What do polar molecules influence
Force of attarction between molecules, therefor nessessary in chemical reactions to form new bonds
Give an example of a polar molecule
Adding OH- to ethonical makes it soluable in the cytosol of the cell and can be used as fuel
Why are functional groups important?
1) Creation of ionic and polar compoinds
2) Ability to bond or release protons (H+) to compounds then acidic or basic
How can bonding and releasing H+ protons make groups more basic or acidic
Accidity is based of amoutn of H in compound. When a carboxyl group (-COOH) releases a H proton, it becomes an acid (-COO-). When NH2 gains a H proton, it becomes a base (NH3).
Name the five main functional groups.
1) Hydroxyl
2) Carbonyl)
3) Carbonxyl
4) Amino
5) Phosphate
What is the structure of Hydroxyl and what is it found in?
Structure: -OH
Found in: Carbohydrates, simple sugars, glycogen, cellulose, starch, glucose
What are properties of hydroxyl
Hydroxyl is really polar (easily dissolved in H20), and turns into alchohol (their specific names usually end with “ol”. Polar as a result of electrons spending more time near oxygen
Examples of hyroxyl
Ethonal, butanol, decanol
What is the structure of carbonyl and what is it found in
Structure: Carbon single bonded to 2 R and double bonded to an oxygen
Found in: Lipids, fats (triglycerides, steriods)
Structures of carbonyl
Keytones: if the carbonyl group is within a carbon skeleton
Aldehydes: if the carbonyl group is at the end of the carbond skeleton
Examples of carbonyl
Acetone (the simplest keytone)
Propanal (an aldehyde)
What is the structure of animo and where is it found?
Structure: N single bonded to two O
Found in: protiens (muscle fibres, enzymes)
Properties of amino
High pH making things basic
Examples of amino
Amino acids, protines, urea, uric acid
Structure of carboxyl and where it is found
Structure: C double bonded to an O and single bonded to an OH
Properties of carboxyl
Has acidic properties beacause the covalent bond between oxygen and hydrogen is so polar
Examples of carboxyl
Lemon, wine, pepsi, coke
Structure of phosphate and where it is found
Structure, P single bonded to two O anions, single bonded to one O and double bonded to one O
Found in: DNA, ATP, RNA, GTP
Properties of phosphate
Has the potential to react with water, releasing energy. Creates the molecule in cell membranes
Examples of phosphate
DNA, RNA, cellular respiration
