Life is composed of…
matter
Matter is anything that
occupies space and has mass
Common Elements of Living Organisms
C,O,H,N (carbon, oxygen, hydrogen, nitrogen)
Atom
the smallest unit of matter that retains all chemical properties of an element
The nucleus contains…
protons and neutrons
The more neutrons and protons in the center of the atom…
the closer electrons are to the nucleus, which means they can be given away easier
Subatomic particles are _____, _______, and ________
protons, neutrons, and electrons
The mass of an electron is…
1/1800 amu
Atomic number
number of protons
Atomic mass =
Protons + neutrons
Isotopes
same number of protons, but neutrons vary
Radioisotopes
unstable isotopes that emit neutrons, protons, and electrons
Atoms with a neutral charge have the same number of…
protons and electrons
Electrons exist on the shells…
closest to the nucleus
Octet rule
when the first two outer shells are filled, each have 8 electrons
The closer the electrons are to the nucleus…
the stronger the pull is
The lower the atomic number…
the lower the pull; more likely to form bonds with other atoms
Electron orbitals helps us to…
predict where an electron might be at any given time
The stronger the pull…
the more organized the movements of electrons
Chemical reactions are
changes in distribution of electrons between atoms
1 mol of a substance is the amount whose mass in _____ equals its molecular mass in _______.
grams; amu
In covalent bonds, electrons are ________
shared
In ionic bonds, atoms _____ or _____ electrons
lose; gain
Metals ______ electrons to achieve the octet rule
lose
Nonmetals _______ electrons to achieve the octet rule
gain
Gaining an electron gives a more _____ charge
negative
Losing an electron gives a more ______ charge
positive
What consist of anions and cations held together by ionic bonds?
salts
Salt is a _____, but NOT a _________
compound; molecule
Covalent bonds in which there is unequal sharing of the electrons are called _______.
polar bonds
Covalent bonds in which there is equal sharing of the electrons are called _______.
non-polar bonds
Both bond type and molecular shape determine if a molecule is ____ or _____.
polar; nonpolar
Weak attractions between two or more molecules in close proximity due to changes in electron density are called _______.
Vand der Waals interactions
Weaker bonds between a proton in one atom, and an electronegative atom in the other are called _________.
hydrogen bonds
Water makes up ______ of the human body
60% - 70%
The most critical molecule for life on earth is…
water
In water, oxygen has the slightly _____ charge
negative
In water, hydrogen has the slightly ______ charge
positive
In liquid water hydrogen bonds are constantly _____, _____, and _______.
made, broken, and remade
In _______, water is heated, kinetic energy increases, causing hydrogen bonds to break + water molecules escape as gas
gas
In _______ temperature is lowered and crystalline structure is maintained.
solid water
Hydrogen bonding makes ice _______ dense than liquid water, which is why it floats in water
less
______ and ______ molecules can dissolve in water
Ions; Polar
Water is a ________
universal solvent
Compounds dissolved or mixed in with the water are called _____.
solutes
Water molecules at the liquid-gas interface stick together due to hydrogen bonding (an attraction between water molecules and other water molecules) is called ______.
cohesion
Surface tension is caused by _______.
cohesion
An attraction between water molecules and other molecules is called ________.
adhesion
Capillary actions is caused by ________.
adhesion
Solutions with high H+ concentration are ______.
acidic
Solutions with high OH- concentration are _______.
alkaline (basic)
Acidic solutions are more likely to _____ protons
donate
Alkaline solutions are more likely to ______ protons
accept
Normal human pH is _______
7.4
Carbon is a key component of ________.
macromolecules (proteins, carbohydrate, lipids and nucleic acids)
Each carbon has ____ electrons in the outer shell and forms _____ covalent bonds to fill the outer shell
This allows it to achieve the octet rule
four; four
Carbon is the _______ for macromolecules
backbone
Hydrocarbons are
hydrogen and carbon
Covalent bonds in hydrocarbons store _______
energy
When hydrocarbons are burned, energy is ________.
released
When carbon forms single bonds with other atoms, it’s shape is…
tetrahedral
When two carbon atoms form a double bond, it’s shape is…
planar, or flat
Single bonds ______ able to rotate
are
Double bonds _______ able to rotate, they are locked in place
are NOT
An important hydrocarbon ring used in some amino acids, cholesterol and its derivatives is called ________.
benzene
________ have different covalent arrangement of atoms
Structural isomers
________ have a different arrangement of atoms around a double bond
Geometric isomers
________ are mirror images
Enantiomers
Trans configuration carbons are on the _____ sides of double bond
opposite
Cis configuration carbons are on the _____ side of double bond
same
Fatty acids with double bond are _______
unsaturated
Fatty acids with no double bonds are _______
saturated
Functional groups interact with each other via ____ ______
hydrogen bonds
Name the functional group
Hydroxyl; Polar
Name the functional group
Methyl; nonpolar
Name the functional group
Carbonyl; Polar
Name the functional group
Carboxyl; Ionizes to release H+ into solution, which is why they are acidic
Name the functional group
Amino; Accepts H+ to form NH₃+, which is why they are basic
Name the functional group
Phosphate; Ionizes to release H+ into solution, considered acidic
Sulfhydryl
Polar
The type of bond in DNA is _________
hydrogen