Chapter 2: The Chemical Level Of Organization Flashcards
Chemistry
The science of the structure and interactions of matter
Matter
Anything that has mass and occupies space.
(Makes up both living and non-living things)
Composed of chemical elements
96% of body mass is made up of…
- Carbon
- Hydrogen
- Nitrogen
- Oxygen
Element
A chemical substance that cannot be broken down into simpler substances.
Each element is composed of identical particles (atoms)
(92 in total, but our body only contains 24 of them)
Protons
Found in the nucleus of an atom.
Has a positive charge (p+)
Neutron
Found in the nucleus of an atom.
Has no charge (n0)
Electron
Travels around the nucleus in shells
Has a negative charge (e-)
Atom
Smallest units of matter that retains properties and characteristics of its element.
Made up of two identical particles (but has 3 subatomic particles)
Electrically neutral because it has equal number of protons and electrons (positive + negative = 0)
Isotope
Atoms of elements that differ in the number of neutrons.
Most are stable but if not they are called radioactive isotopes (will emit radiation trying to become stable)
Mass
The amount of matter in an object
(Always constant because it’s not associated with its weight)
(Properties: Solid, liquid, or gas)
Ion
When an atom becomes charged by gaining or losing an electron.
Positively charged ion = cation
Negatively charge ion = anion
Molecule
Formed when 2 (or more) atoms join by a chemical bond.
Chemical bond
Achieves complete electron shells, which allows chemical stability.
(Most stable when outer shell holds 8 electrons)
Types = ionic, covalent, hydrogen
Ionic bonds
Formed by the transfer of electrons from one atom to another.
Ex. NaCl
Covalent bond
Formed by the sharing of pairs of electrons between 2 or more atoms
2 types:
Nonpolar - electrons shared equally between atoms
Polar - electrons not shared equally between atoms
Hydrogen bond
Formed when a hydrogen atom with a partial positive charge attracts with partial negative charge of a nearby electronegative atom (usually N or O)
Chemical reactions
Occur when bonds are formed, broken, or rearranged.
(Requires reactants and products)
Can change rate of reaction with things like a catalyst, adding heat, decreasing particle size.
Compound
A substance composed of two or more elements joined by chemical bonds
Energy
The capacity to do work
2 main forms of energy:
- Potential energy
- Kinetic energy
Potential energy
Energy stored by matter due to its position.
(essentially the energy is waiting to be released)
Ex. Being at the top of the roller coaster anticipating the drop
Kinetic energy
Energy associated with matter in motion.
Ex. Going down the roller coaster
Chemical energy
A form of potential energy that is stored in the bonds of compounds and molecules.
Activation energy
Energy required to disrupt the electrons, and get the molecules to interact and form reactions.
Catalyst
(Typically an enzyme)
Speeds up reactions by lowering the activation energy.
Synthesis reaction
(Anabolic)
Two or more atoms, ion, or small molecules join together to form a large molecule.
A + B –> AB
They are endergonic: absorb more energy than they release
Decomposition reactions
(Catabolic)
A larger molecule is broken down into smaller molecules, ion, or atoms.
AB –> A + B
They are exergonic: release more energy than they absorb.
Exchange reactions
Involve both synthesis and decomposition;
Parts of 2 difference molecules trade positions with one another.
AB + CD –> AD + BC
Atomic number
The number of protons in the nucleus of an atom.
Mass number
The sum of the number of protons and neutrons in the nucleus.
Inorganic compounds
Lack carbon and are structurally simple
Ex. Water, salts, acids, bases
Organic compounds
Built by joining monomers (small molecules) together into polymers (large molecules).
Always contain carbon (and usually hydrogen). They are formed by covalent bonds.
Ex. Carbohydrates, lipids, proteins, ATP, nucleic acids
Water
Inorganic compound
Most important inorganic compound in all organisms.
Properties:
- high heat capacity
- high heat of vaporization
- polar solvent
-cushioning and lubricating effect
Salts
Inorganic compound
Dissociate when dissolved in water, which produces oppositely charged ions called electrolytes.
Dissociate into positive and negative ions (neither one which is H+ or OH-)
Acids
Inorganic compound
(A proton donor)
Dissociate when dissolved in water, producing oppositely charged ions called electrolytes.
Dissociate into 1 (or more) hydrogen ions (H+), and I (or more) negative ions (__-)
Ex. HCl –> H+ + Cl-
Bases
Inorganic compound
(A proton acceptor)
Dissociate when dissolved in water, producing oppositely charged ions call electrolytes.
Dissociate into 1 (or more) hydroxyl ions (OH-) and 1 (or more) positive ions (__+)
Ex. NaOH –> Na+ + OH-
Electrolytes
Oppositely charged ions that are produced when a salt, acid, or base is dissolved in water
Ex. NaCl –> Na+ and Cl-
pH scale
Based on the concentration of H+ in a solution.
Has values from 0-14:
pH < 7 = acidic (H+ > OH-)
pH > 7 = basic (H+ < OH-)
pH = 7 = neutral (H+ and OH- balance)
Buffer system
The body’s way of minimizing changes in the pH of solutions by converting strong acids/bases into weak acids/bases.
(Will absorb/bond with strong acids/bases in order to neutralize it more)
Carbon
Has 4 valence electrons so it will typically form 4 covalent bonds with other elements to complete it.
Dehydration synthesis
Monomers are joined by removal of OH from one monomer and removal of H from the other during bond formation.
Hydrolysis
Monomers are released by the addition of a water molecule, adding OH to one monomer and H to the other.
Carbohydrates
Organic compound
Composed of C, H, and O.
The main source of chemical energy for metabolism.
Includes: sugars, glycogen, starches, cellulose.
Monosaccharides
A monomer of carbohydrates.
5 are needed in the body:
glucose, fructose, galactose, ribose, deoxyribose
General formula: (CH2O)n
(n= number that you x each component by)
Disaccharides
Formed by a dehydration synthesis to join 2 monosaccharides into a pair.
3 are needed in the human body:
Sucrose, lactose, maltose
Polysaccharides
Large chains or many monosaccharides joined together.
3 needed in the body:
Starches, glycogen, cellulose
Isomers
A group of molecules with the exact same number of atoms and molecular formula, but arranged differently (which allows for different chemical properties)
Lipids
Organic compound
Composed of C, H, O (but less O)
Includes: triglycerides, phospholipids, and steroids.
Lipids are nonpolar, so they will not dissolve in water (hydrophobic), but other lipids will dissolve lipids.
Triglycerides
aka: fats (if solid) and oils (if liquid)
Composed of glycerol and 3 fatty acid chains. Form via dehydration synthesis.
Found mostly in body tissues. Important for storing energy, insulation, and shock absorption.
Phospholipids
Composed of glycerol, 2 fatty acid chains (nonpolar tails), and a phosphate group (the polar head.)
This is mostly found in membranes.
Steroids
Consist of 4 interlocking carbon rings with various side groups.
Includes: cholesterol and steroid hormones (such as sex hormones)
Proteins
Organic compound
Composed of C, H, O, and N
They are polymers built from 20 different amino acids, linked by peptide bonds.
Amino acids
A molecule composed of an amino group and a carboxyl group, with a extra side chain (R). They are joined by peptide bonds via a dehydration synthesis.
They are buffers that regulate strong acids/bases.
4 structural levels of proteins
1) Primary structure: linear sequence
2) Secondary structure: alpha helix or beta pleated sheet
3) Tertiary structure: complex globular shape.
4) Quaternary structure: interaction if 2 or more polypeptides (tertiary structures)
2 classifications of proteins
1) Structural (fibrous)
- stable and insoluble in water
- provide mechanical support and give strength
2) Functional (globular)
- less stable, H-bonds break easily
- are water soluble
Enzyme
A natural catalyst which will increase the rate of a specific chemical reactions.
(Proteins function as enzymes)
Suffix = “ase”
Ex. Lipase (if it has “ase” it is likely an enzyme.
Nucleic acids
Organic compound
Composed of C, H, O, N, P
They are chains of nucleotides, which are made up of a 1 or more phosphate groups, a pentose sugar, and a nitrogen base.
2 types of Nucleic acids
1) Deoxyribonucleic acid (DNA)
2) Ribonucleic acid (RNA)
Deoxyribonucleic acid (DNA)
A double stranded polymer (in a ladder shape that is twisted).
The 2 strands are made up of nucleotides bound together.
Needs nitrogen bases: adenine, cytosine, guanine, or thymine. They pair together (A&T, C&G) and are the “steps” of the ladder.
DNA is the storage for genetic info
Ribonucleic acids (RNA)
Consists of a single strand of sugar phosphate, and studded with the nitrogen bases (but uracil replaces thymine)
It carries genetic instructions from DNA to the cells ribosomes in the cytoplasm.
Adenosine Triphosphate (ATP)
Organic compound
Consists of the nitrogen base adenine, 5 carbon sugar (ribose), and 3 phosphate groups.
It is a molecule that cells use to perform various actions.
