1.1 the fundamental chemistry of life Flashcards
matter is made up of
atoms
what are elements?
pure substances
what are organic compounds?
compounds that contain carbon (may also have H and O)
living things are mostly made up of (list percentage)
CHON - 96%
living things also contain (4%)
Chlorine, calcium, phosphorus, potassium, Sulphur, sodium, magnesium
trace elements are: (<0.1%)
iodine and iron
atoms are composed of:
protons neutrons and electrons
what determines the type of element?
protons
T or F? atoms are neutral
T
What is atomic mass?
weight of protons and neutrons
What is an isotope?
form of an element with same # of protons but different # of neutrons
T or F? Isotopes behave the same in a reaction
T
Radioisotopes
unstable isotope that decays, giving off radiation - transforms into an atom of another element
Example of a radioisotope
14C is unstable - one neutron splits into an electron + proton - decays into 14N
Radioactive decay
occurs at a steady and
measurable rate
Anion
negative ion
Use of radioactive decay
used to determine the
age of rocks and fossils
Radioactive tracers
radioisotopes used
to trace the path of atoms throughout the body
Cation
positive ion
Covalent Bonds
atoms SHARE valence
electrons
Ionic Bond
between two
oppositely charged atoms/molecules
Electronegativity
measure
of an atom’s attraction to shared
electrons
High electronegativity
strong attraction of e-
Low electronegativity
weak attraction of e-
Polar Covalent Bond
unequal sharing of electrons
Are polar molecules water soluble?
generally yes
Are non-polar molecules soluble in water?
generally not
water soluble
Intermolecular forces
Forces of attraction between molecules
3 types of intermolecular forces
Hydrogen bonds, dipole-dipole, van der waal forces
Hydrogen bonds
attractive force between slightly positive hydrogen atoms and a slightly
negative atom in another molecule
Dipole - Dipole
attractive force between
slightly positive atoms (not hydrogen) and a slightly
negative atom in another molecule
van der Waal Forces
very weak attractions between two molecules, or parts of molecules when they are close together
how do van der waal forces form
Form from the momentary
attractions of electrons to nuclei
of other molecules
True or false: Smaller molecules have larger
forces of attraction than larger
molecules
F
4 Main common biological reactions:
Dehydration synthesis, hydrolysis, neutralization, redox
Dehydration Reaction (Condensation reaction):
Join 2 molecules by removing water - takes energy to make complex structures (one molecule loses H, the other loses -OH)
Hydrolysis
splitting a larger molecule apart by adding water - gives off energy (adds -OH to one molecule and H to the other)
Neutralization Reaction
a reaction in which
an acid + base combine to create a salt +
water
Redox reaction
an electron transfer reaction
Reduction
gaining of electrons
Oxidation
loss of electrons
