Chapter 2: Life Chemistry and Energy Flashcards
atom
smallest unit of matter that defines chemical elements
nucleus
Dense and positively charged
electrons
negatively charged
negligible mass
protons
positively charged
mass of 1
neutrons
no charge
mass of 1
element
oure substance
just one kind of atom
True or false: like charges attract
false, they repel
opposite charges attract
dalton
unit of measure
mass of a proton
What are the six major elements in organisms?
Hydrogen (H) Nitrogen (N) Sulfur (S) Phosphorous (P) Carbon (C) Oxygen (O) CHNOPS
atomic number
number of protons in an atom
unique to each element
mass number
neutrons and protons
Bohr Model
largely empty space
central nucleus
electrons orbit
electron shells
electrons in orbit
molecules
atoms bonded together
octet rule
atoms like to form stable molecules so that have 8 elections in their outermost shells so they can be super happy
chemical bond
attractive force that links two atoms together in a molecule
Ionic bonds
form when atoms gain or lose one or more electrons to achieve stability
covalent bonds
atoms share electrons
strong
Hydrogen bonds
weaker
SUPER IMPORTANT IN BIO
#proteins #water #literallyeverythingever
Functional Groups
groups of atoms that give important properties to biological molecules
Ion
electrically charged particle that froms when an atom gains or loses one or more electrons
Cations (CatIons)
positively charged ions
think Na+
Anions (AnIons)
negatively charged ions
Think Cl-
Ionic bonds
form as a result of the electrical attraction between ions bearing opposite charges
Salts
products of ionic bonds
Are ionic bonds typically strong in living systems?
Nope, they are typically weak (they are in solutions)
generally water
and salts dissolve in water
Covalent Bond
two atoms attain stable electron numbers in their outermost shells by sharing one or more pairs of electrons
single bond
sharing of a single pair of electrons
double bond
involves the sharing of four electrons, two pairs
Triple bonds
rare
six shared electrons
like the gold standard of bonds
electronegativity
the attractive force that an atomic nucleus exerts on electrons in a covalent bond
nonpolar covalent bonds
atoms have very similar electronegativities
share electrons equally
Polar covalent bond
unequal electron sharing
drawn to more electronegative nucleus
hydrogen bond
Hydrogen + really electronegative molecule
weaker than covalent
heat capacity
how much heat needs to be added for a temperature change
Heat of vaporization
the heat required to change from liquid to gaseous state
Cohesion
capacity to resist coming apart when placed under tension
Hydrophilic
water loving
polar
Hydrophobic
water hating
nonpolar
hydrocarbon molecules
Macromolecules
large molecules
formed by covalent linkages of smaller molecules
polymers
most biological molecules constructed by the covalent bongin of smaller monomers (except lipids like to be different and do their own thing)
Condensation
removal of water links monomers
hydrolysis
water breaks polymer into monomers
Carbohydrates
large group of molecules that all have similar atomic compositions but differ in sixe, chemical properties, and biological functions
general forumla Cn(H2O)n
Important roles of Carbohydrates
source of stored energy that can be released in a form usable by organisms
used to transport stored energy
function as structural molecules
recognition or signaling molecules
Lipids
hydrocarbons
insoluble in water
nonpolar covalent
Important roles of lipids
store energy in C-C and C-H bonds
structural roles in cell membrane sand on body surfaces
thermal insulation
nucleotide
consists of three components: a nitrogen-containing base, a pentose sugar
DNA
deoxyribonucleic acid
RNA
ribonucleic acid
Catalysts
substances that speed up reactions without themselves being permanently altered
increases rate of reaction
CAN NOT MAKE REACTIONS OCCUR
enzymes
proteins
biological catalysts
Transition state
reactive mode caused by an input of energy
Activation energy
the energy required to make a reaction happen
Active site
where molecules bind to
Enzyme-substrate complex (ES)
binding of a substrate to the active site of an enzyme produces this
competitive inhibitor
competes with substrate for the active site
noncompetitive inhibitor
binds to an enzyme at a site distinct from active site
Allosteric Regulation
non-substrate molecule binds or modifies a site other than the active site of an enzyme
Anabolic Reactions
link simple molecules to form more complex
capture energy
endergonic
endothermic
Catabolic Reactions
break down complex molecules into simple
release energy
exergonic
exothermic
First law of thermodynamics
energy is neither created nor destroyed
second law of thermodynamics
disorder tends to increase
chaos is a ladder
