Chemical Basis Of Life Flashcards
Most abundant atoms in human body
H>O>C
Electrons sharing equally vs unequally and their probable atoms
Equally = non-polar covalent bond
*C,H
Unequally = polar covalent bond
*O,N,S
NonCovalent Bond
1- Ionic
2- HB
3- Hydropholic attraction
4- Van der Waals
Ionic bonds in water
Ionic bonds in crystals are quite strong but in water: ions become surrounded by water and inhibit oppositely charged ions from approaching one another
Ionic bonds in DNA
Positively charged groups on surface of a protein AND negatively charged phosphate atoms
Ionic bonds in the cell is weak due to water but in core of a protein (no water) bonds are more stronger
HB
Hydrogen Bonds
Hydrogen is covalently bonded to one atom in order to be hydrogen bonded (covalently) to another
Their strength is additive
Hydrophobic Interactions
-Desire of hydrophobic molecule to NOT INTERACT with water
-Not energetically favorable
-Non-polar molecules aggregate to reduce exposure to water
Van der Waals
-Weak attraction between uncharged molecules
-Optimal Van der Waals is not the closest
Non-covalent Interaction at room temperature
Due to weak interaction (low energy) continually formed and reformed at room temperature
Water Functions
1-75% of a cell weight
2- Polar molecule
3- All three atoms can form hydrogen bonds
4- Each water molecule can form maximum 4 HBs
5- Most of molecules in the cell are polar so can form HB with water
6- Water will form HBs with other water molecules surrounding non-polar molecules
7- Water Hydrophobic effect will minimize water molecules surrounding and increase water entropy
8- High boiling point
9- High heat of vaporization
10- High specific heat
Metabolic reactions efficiency
About 50%
Biochemicals
Produced by living organisms
Most of the dry weight of organisms
Carbon
Cholesterol
Various arrangements of carbon atoms
Ester
Carboxylic acid
Alcohol
