Matter
Anything that takes up space and has mass
Mass
The amount of matter a substance contains; weight is the force of gravity acting on mass
What are the three forms of matter?
solid, liquid, gas
What are the four Major Elements?
Oxygen (O), Carbon (C), Hydrogen (H) and Nitrogen (N)
Function of (O)?
Used to generate ATP (Adenosine Triphospate)
Function of (C)?
Forms chains and rings of all organic molecules; proteins and nucleic acids (DNA and RNA)
Function of (H)?
Ionized form (H+) makes fluids more acidic
Function of (N)?
Component of all proteins and nucleic acids
___ are positively charged atoms, and are located in the nucleus
Protons
___ are atoms that have no charge, in the nucleus.
Neutrons
___ are negatively charged atoms, that forms a cloud outside the nucleus.
Electrons
Only ___ electrons can be in the first shell.
2
How many electrons can be in the second shell?
8
How many electrons can be in the third shell?
18
The ___ is the number of protons in an atom.
Atomic number
The atomic number is also the ___.
number of electrons
What is the mass number?
The number of protons and neutrons in an atom.
What are isotopes?
Different atoms of the same element with the same number of protons, but different number of neutrons, thus different mass number.
Why are radioactive isotopes unstable?
Their nuclei decay to make a simpler form and as they decay they emit radiation.
___ of an element is the average mass of all its various isotopes of the various types.
The atomic mass/weight
What is an ion?
An atom that has a positive or negative charge after giving or gaining an electron.
What is a free radical?
An atom or group of atoms with an unpaired electron in the outermost valence shell.
How do free radicals become stable?
By giving or taking another electron.
What is a compound?
Molecules that contain two or more different kinds of elements.
Chemical bonds are when ___.
the atoms of a molecule are held together by forces of attraction.
What determines the likelihood of an atom forming a chemical bond with another atom?
The number of electrons in its valence shell.
Describe the Octet Rule
Atoms that have incomplete outer shells tend to combine with each other in chemical reactions to make a chemically stable arrangement of eight valence electrons.
What are ionic bonds?
When atoms lose or gain one or more electrons and holds ions of opposite charge (opposites attract).
___ and negatively charged ions are attracted to one another.
Positively
___ are positively charged ions that gave away one or more electrons (donors).
Cations
Who are the receivers in a bond?
Anions; negatively charged ions that receive one or more electrons from another atom.
What kind of bond is formed when the electrons are being shared between two or more atoms?
Covalent bond
What is a triple covalent bond?
When three pairs of electrons are being shared.
What is a nonpolar covalent bond?
The equal sharing of electrons, one doesn't attract more strongly than the other and the number shared is the same.
Polar covalent bonds are ___.
when atoms are sharing electrons unequally, one atom attracts more strongly than the other.
Hydrogen bonds are when ___.
two other atoms associate with a (H) atom.
What kind of bond gives water considerable surface tension?
Hydrogen bond
Why can't hydrogen bonds bind atoms together?
They only serve as links between molecules.
What kind of bond is this?
Polar covalent bond.
What kind of bond is this?
Nonpolar covalent bond
When do chemical reactions occur?
When new bonds are formed and old bonds break.
Reactants are the
starting substances of a chemical reaction.
Products are the
ending substances.
___ is when the total mass of the reactants and the products stay the same before and after a reaction. They only have different chemical properties because they've been rearranged.
Law of conservation of mass
___ is energy stored in matter due to its position.
Potential energy
A person ready to jump down some steps is an example of?
Potential energy
What is kinetic energy?
Energy in motion
A person jumping down some steps is an example of?
Kinetic energy
What is chemical energy?
It is a form of potential energy that is stored in the bonds of molecules and compounds.
The law of conservation of energy is when?
The amount of energy at the beginning and end of a chemical reaction is the same.
Energy can't be...?
created or destroyed, but it can be altered to be something else.
Describe exergonic reactions
When a product has more energy before it was broken.
When do exergonic reaction occur?
Catabolism
Describe endergonic reactions
When a product absorbs more energy than they release.
Activation energy is the ___.
collision energy needed to break chemical bonds.
What are some factors that can influence the chance of a collision?
Temperature and concentration
What are catalysts?
Chemical compounds that speed up reactions by lowering the activation energy needed for one to occur.
Does a catalyst alter the potential energy of the reactants and products?
No, it only lowers the amount of energy needed for a reaction.
What is a synthesis reaction?
Reactions that combine to form new and larger molecules; they are anabolic.
A catabolic/decomposition reaction occurs when ___.
a molecule is broken down into smaller parts.
What is an exchange reaction?
It is when an atom(s) is replaced by another atom.
What is a reversible reaction?
When products can revert back to the reactants.
What do inorganic compounds lack?
Carbon
Organic compounds always have ___.
Carbon and hydrogen, and usually have oxygen.
What type of bond do organic compounds always have?
Covalent
Water is an ___.
inorganic compound
Substances with polarity ___.
dissolve in water because they are hydrophilic
Nonpolar substances are ___.
hydrophobic
What does hydrolysis do?
It breaks larger molecules into simpler ones by adding a water molecule.
What type of reaction is hydrolysis?
Decomposition
What does dehydration synthesis do?
It makes new bonds by removing a molecule of water.
Where is water found in the body?
Wherever friction needs to be reduced or eliminated (joints, bones).
A ___ is a combo of elements or compounds that are physically blended together but not chemically bound.
mixture
A solution is ___.
a solute being dissolved in the solvent
What is a colloid?
A mixture that has large enough particles in it to scatter light. Usually transparent.
What is an example of a colloid?
Milk
Suspensions are ___.
heterogeneous mixtures that will have one material suspended, but will eventually settle at the bottom.
Oxidation-Reduction is the ___.
transfer of electrons between atoms and molecules.
Acids
Ionize into one or more (H+) ions and one or more anions. (H+ and Cl-)
Bases
Dissociates into one more hydroxide ions (OH-) and one or more cations. (K+ and OH-)
Salts
Dissociates into cations or anions, neither (H+) or (OH-). Formed when acids and bases react with each other. (K+ and Cl-)
What does the pH scale measure?
The acidity and alkalinity of a solution.
>7 on the pH scale indicate what?
The acidity of a solution
<7 on the pH scale indicate what?
The alkalinity of a solution
What does a buffer system do?
To convert strong acids into weaker acids or bases.
The carbonic and acid-bicarbonate is ___.
an important buffer system in our body.
___ is a chain of carbon atoms in an organic molecule.
Carbon skeleton
What are monomers?
Identical or similar small building-block molecules (macromolecules).
When many monomers are covalently bonded to each other, what does it form?
Polymer
What is an isomer?
They are molecules that have the same molecular formula but have different structures.
Carbohydrates can be divided into three major groups (based on their sizes):
Monosaccharides, disaccharides, polysaccharides
How are disaccharides formed?
Formed from two monosaccharides by dehydration synthesis.
Sucrose = glucose + fructose, is an example of what?
Hydrolysis of a disaccharide
How do lipids become soluble?
By combining with proteins and forming lipoproteins.
What are the functions of proteins? (Name at least one)
They give structure to the body, regulate processes, provide protection, help muscle contractions, transport substances and serve as enzymes.
What creates proteins?
Amino acids
Enzymes are ___.
catalysts of a living cell
___ forms the genetic code inside each cell and regulates most of the activity that takes place in out cells.
DNA
___ relays info from the genes in the cell's nucleus to guide each cell's assembly from amino acids into proteins.
RNA
Adenine (A), Thymine (T), Cytosine (C), Guanine (G) and Uracil (U) are called ___.
Nitrogenous bases
How is DNA copied?
It is self-replicating
How is RNA copied?
Made by DNA as a blueprint
What types of RNA are there?
Messenger (mRNA) and transfer (tRNA)
What does ATP stand for?
Adenosine Triphosphate
Name at least one function of ATP
Muscle contractions, chromosome movement during cell division, cytoplasmic movement within the cells, membrane transport processes and synthesis reactions