Chemical Foundations Part 1 Flashcards
Covenant Bonds
High dissociation energy
Number of bonds depends on atom size and electron distribution
Delocalized Covenant Bonds
More than one pattern
electrons are not associated with any of the molecules
Bonds between two non-metals
Covalent– sharing of electrons
Bonds between metal and non metal
Ionic –transfer of electrons
What happens in Ionic Bond?
Metal losses electron to positively charged and nonmetal accepts electron to be negatively charged
How is Bond Geometry Determined?
by type of bonds and by number of electron shared
*no rotation around double bonds
What are different types of covenant Bonds?
Singe Double Tripple Polar Nonpolar
Polar bonds
unequal electron sharing *determined by electronegativity
permanent dipole
partialy +
Partialy-
Nonpolar Bonds
equal electron sharing
Define dipole
magnetic field between + and - charged poles separated by distance
Define polar covalent
unequal sharing of electrons (Partialy ionic )
Nonpolar covenant
equal sharing of electrons
Where do noncovenant bonds come into play?
they help with folding of proteins and nucleic acids
plasma membrane
Explain common functional groups
Hydroxyl --alcohol Acyl--- tryglycerol Carbonyl--ketone Carboxyl ---carboxylic acid Sulfhydryl---thiol Amino--- amines Phosphate Pyrophosphate
What is a Phosphoanhydride bond and whys it so high in energy?
its composed of nitrogenous purine Nadine , ribose sugar and there phosphate sugars
they are high in energy because when they are broken a tremendous amount of energy is released
Properties of water
high melting point high boiling point highly cohesive easily dissolves polar and charged molecules permanent dipole
why life is based on carbon?
carbon is very abundant
key component of all known life on earth
along with nitrogen and oxygen
18% in body
unique because can form four different bonds with other elements
Does water affect Ionic bonds?
Yes, bonds are very strong with the absence of water
water causes partial neutralization of charges
explain Van der Walls interactions
Attractive forces due to fluctuation of electron around atoms (between molecules of the same substance)
TRANSIENT-partial charges
dipoles
distance dependent
weak
NOT AFFECTED BY WATER
important for interactions of non polar substances in water
Can non polar molecules participate in hydrogen bonding?
No, caged by water molecules
Covenant Bonds in DNA
sugars phosphate bonds with nitrogenous bases
Noncovalent forces in DNA
Hydrogen bonds between nitrogenous bases hydrophobic effect van der walls interactions in single and double DNA electric repulsion
Molecular Complementaire
lock and key
mediated by non covenant forces between molecules
what is Stereochemistry?
three dimensional arrangement of a molecule
Explain Configurational Isomers
Cannot be interconverted without breaking a bond Double bonds chiral center optical isomers rotate plain polarized different biological activity
Explain Conformational isomers
CAN be interconverted by just rotation
What are the types of Stereoisomers?
Enantiomers–mirror images
Diastereomers non mirror images
Strong acid/base
Complete dissociation/protonation
Weak acid/base
incomplete dissociation/protonation
