Chapter 2 - Chemistry Flashcards
Ion
- formed by gaining or losing electrons
- anion is a negative ion that has gained one or more electrons
- cation is a positive ion that has lost one or more electrons
Basic Atomic Structure
- nucleus contains protons(+) and neutrons(no charge)
- nucleus is surrounded by electrons(-) and shells
- outermost electrons are involved in chemical reactions
Anion
- when one or more electrons are gained
- charge becomes negative (-)
Cation
- when one or more electrons are lost
Covalent Bond
- sharing of a pair of electrons by two atoms
- very strong bond
- chemical bond
Electronegativity
- attraction of an atom for electrons
- the more electronegative an atom, the greater the pull it’s nucleus exerts on electrons
Nonpolar Covalent Bonds
- when electrons are shared equally between two atoms
- hydrophobic
- happens when atoms have similar electronegativities
- no poles exist
Polar Covalent Bonds
- when there is an unequal sharing of electrons between two atoms
- partial + and partial - charge within the molecule
- can be slightly weaker than normal covalent bonds
- most important are Hydrogen + another atom bonding
- very “sticky”
Ionic Bonds
- formed from the electrostatic attraction of cations and anions ( + and - attract each other)
- no electron is shared
- salts
- not as strong as covalent bonds
- can be broken by polar solvents (water)
Hydrogen Bonds
- polar covalent bonds
- made between a hydrogen and a partial negative center
- generally with O or N
- much weaker than covalent bonds
- hold rungs of DNA ladder together, so they need to be weak enough to be broken apart for replication
pH
- measure of hydrogen potential of a substance
- water is neutral, so the neutral pH is 7
- less than 7 = acidic because there is more H+
- more than 7 = alkaline/basic because there is less H+
Synthesis Reaction
- formation of larger, more complex molecules
- endothermic (heat requiring) and endergonic (energy requiring)
- anabolic (building up)
- common type is dehydration synthesis
- all synthesis reactions in the body together called anabolism
Metabolism
all reactions in the body
Anabolism
- building up reactions
reactant + reactant = product
Catabolism
- breaking reactions
reactant = product + product
Decomposition Reaction
- break bonds with larger molecules to form smaller ones
- reactant = product + product
- exothermic (heat releasing) and exergonic ( energy producing)
- catabolic (breaking down)
- ex. hydrolysis
Dehydration Synthesis
- synthesis reaction / anabolic
- opposite of hydrolysis
H-smallmolecule - smallmolecule-OH —> LARGEmolecule-OH + H20
^energy
Hydrolysis
- decomposition reaction / catabolism
- opposite of dehydration synthesis
HLARGEmoleculeOH + H20 —> HsmlmoleculeOH - HsmlmoleculeOH
!energy leaves
Lipid
- hydrophobic
- fats, phospholipids, waxes, steroids