THE CHEMICAL BASIS OF LIFE Flashcards
study of matter
including:
- * Structure of atoms
* Basic chemical building blocks
* How atoms combine to form increasingly complex structures
Chemistry
Anything that takes up space and has mass
- Made up of atoms
Matter
3 Subatomic particles
- Protons
- Positive charge
- Neutrons
- Neutral
- Electrons
- Negative charge
Number of protons
Atomic number
Contains protons and neutrons
- surrounded by electrons
Nucleus
Spherical area that contains electrons
Electron cloud
Two-dimensional representation of electron cloud
Electron shell
made up of protons and neutrons located in a central nucleus
atom
substance that consists of only one type or kind of atom.
Element
outermost shell of any atom
- it determines bonding
valence shell
chemical reactivity of an atom is determined by its
electronegativity
Three major types of chemical bonds
- Ionic bonds
- Covalent bonds
- Hydrogen bonds
Involve sharing, gaining, and losing electrons
Chemical bonds
are attractions between cations (positive ions) and anions (negative ions)
Ionic bonds
One atom-the electron donor-loses one or more electrons and becomes a
cation
Another atom-the electron acceptor-gains those same electrons and becomes an
anion
Strong bonds involving shared electrons
Covalent bonds
Sharing one pair of electrons is a
single covalent bond
2 types of covalent bonds
- Nonpolar covalent bonds
- Polar covalent bonds
Equal sharing of electron pairs
Nonpolar covalent bonds
Unequal sharing of electron pairs
Polar covalent bond
weak type of force that forms special type of dipole-dipole attraction between molecules
Hydrogen Bonds
two or more atoms chemically combined to form a structure that behaves as an independent unit
Molecule
two or more different types of atoms chemically combined.
Compound
is the separation of ions in an ionic compound by polar water molecules.
Dissociation
the combination of reactants to form a new, larger product.
Forms chemical bonds
synthesis reaction
the breakdown of larger reactants into smaller products.
Breaks chemical bonds
decomposition reaction
a combination of a decomposition reaction and a synthesis reaction, in which the products of the decomposition reaction recombine
exchange reaction
reactants can form products, or the products can form reactants
the amount of reactant relative to the amount of product is constant at equilibrium.
reversible reaction
stored energy that could do work
Potential energy
the capacity to do work
Energy
does work by causing the movement of an object
kinetic energy
Energy exists in chemical honds as
potential energy
can be neither created nor destroyed, but one type of energy can be changed into another
Energy
must be added in reactions when the products contain more potential energy than the reactants.
Energy
the amount of energy needed to start a reaction
Activation energy
are protein catalysts that lower the activation energy of reactions
Enzymes
regulate chemical reactions (enzymes)
Proteins
building blocks of proteins are
amino acids
Accounts for up to two-thirds of total body weight
Water (H₂O)
Interact with water
Hydrophilic
Do not interact with water
Hydrophobic
2 water compounds
Hydrophilic and hydrophobic
is a measure of the concentration of hydrogen ions solution
pH (potential of hydrogen)
More H+ ions means
lower pH
fewer H+ ions means
higher pH
Has an inverse relationship with H+ concentration
pH scale
normal/neutral pH solution
7.0
higher than 7.0
- Low H+ concentration
- High OH- concentration
Basic (or alkaline) solution
pH of human blood
Ranges from 7.35 to 7.45
lower than 7.0
- High H+ concentration
- Low OH- concentration
Acidic solution
proton acceptors
Bases
proton (H’) donors
Acids
forms when an acid reacts with a base
Salts
chemicals that resist changes in pH when acids or bases are added
Buffers
