Chapter 2: Molecules of Life Flashcards
3 parts of an atom
potion +, electron -, neutron
Isotopes
atoms of the same element with a different # of neutrons
Ions
charged atoms
loss of election +
gain of electron -
Electronegativity
ability for atoms to attract to each other. electrons closer to the nucleus have less energy
molecule
groups of 2 or more atoms
chemical bond
any form of attraction between atoms
Covalent bond
chemical bond formed by shared pair of electrons
Ionic bond
attraction of 2 atoms b/c of opposite charges
polar and non polar covalent bonds
polar: bonds do not share electrons equally
non polar: Electronegativity between atoms very similar; do not mix well with water, good for body
2 uses of chemical bonds
build/break down bonds, hold/release energy
polar
molecule w/ + and - parts
solvent
liquid capable of dissolving a substance
hydrophobic effect
exclusion of polar and non polar molecules
ex) oil on top of water
Hydrogen bond
an interaction between a hydrogen atom and an electro negative atom
3 properties of water from hydrogen bonds
Water expands and becomes less dense when it freezes, cohesion, regulates body temperature
What is pH?
Measure of the proton concentration H+
Isomers
molecules that have the same chemical formula but different structures
proteins
key structural and functional molecules that do the work of the cell, provide support, and catalyze chemical reactions
nucleic acids
polymer of nucleotides that encodes and transmits genetic information
carbohydrates
organic molecule that provides energy for metabolism and forms the starting point for all other organic molecules
lipid
organic molecule that stores energy, acts as a signaling molecule, and makes up the cell membrane
polymers
complex molecule made up of repeated similar units covalently bonded
amino acids
-structure
building block of proteins
-central carbon, hydrogen atom, carboxyl group, amino group, and r group (side chain)
sugar
saccaride; simplest form of carbohydrate
fatty acid
triglycerol
long chain of carbon attached to a carboxyl group used for storage, 3 fatty acid chains attached to glycerol
functional group
groups of one or more atoms that give certain properties of their own regardless of what they are attached to.
Functional group examples
amino (-NH2)
carboxyl (-COOH)
hydroxyl (-OH)
methyl (-CH3) non polar
enzymes
proteins that function as catalysts for chemical reactions
R group
determine identity of the amino acid
peptide bond
covalent bond that links two AA’s (releases H2O)
pyrimidine
single ringed bases:
C-cytosine
T-thymine
U-uracil
purine
bases w/ double ring structures
G-guanine
A-adenine
phosphodiester bond
bond that forms when two nucleotides bond together covalently; phosphate to sugar
glycosidic bond
covalently bonds 2 monosaccharides together; releases H2O
Lipids
share a property not a structure, hydrophobic; very little oxygen
saturated and unsaturated fats
saturated: max number of hydrogen atoms on carbon chain; fatty acids that contain all single bonds
unsaturated: fatty acid chain with one or more double bonds
phospholipid
makes up cell membrane
Building blocks of life
water vapor, methane, ammonia, hydrogen gas
