Chapter 2 Flashcards
What is an element?
The simplest form of matter to have unique chemical properties
What is an atomic number?
Number of protons in an element’s nucleus
What atoms are found in the nucleus?
Protons and neutrons
What atom is found outside the nucleus?
Electrons
What are valence electrons?
Electrons in the outermost shell that determine an atom’s chemical bonding properties
What is atomic mass?
The total number of protons and neutrons
What are isotopes?
Varieties of an element that differ in number of neutrons (and atomic mass)
What is an ion?
A charged particle (atom or molecule) with unequal numbers of protons and electrons
What is an anion?
A particle with a net negative charge (more electrons than protons)
What is a cation?
A particle with a new positive charge (less electrons than protons)
What are electrolytes?
Substances that ionize in water and form solutions capable of conducting electric currents
Why are electrolytes important?
Chemical reactivity, osmosis, electrical excitability of nerve and muscle
What are free radicals?
Short-lived particles with an unusual number of electrons, can trigger destructive and harmful reactions
What are antioxidants?
Chemicals that neutralize free radicals
What is a molecule?
A chemical particle composed of two or more atoms
What is a compound?
A molecule composed of 2 or more different elements
What is a chemical bond?
Something that holds atoms together within a molecule or attracts molecules to each other
What are ionic bonds?
Attractions between anions and cations where they exchange electrons. Easily broken by water
What are covalent bonds?
2 molecules sharing electrons. Polar and non-polar
When is a covalent bond polar?
When the electrons are not shared equally between the molecules
What is a hydrogen bond?
A weak attraction between a slightly positive hydrogen atom in one molecule and a slightly negative oxygen or nitrogen atom in another
How are water molecules attracted to one another?
Hydrogen bonds
What is a mixture?
Something physically blended but not chemically combined
What are the 5 properties of water?
Solvency, cohesion, adhesion, chemical reactivity, and thermal stability
Solvency is
The ability to dissolve other chemicals
Adhesion is
Tendency of one substance to cling to another
Cohesion is
Tendency of like molecules to cling to each other
Chemical reactivity is
The ability to participate in chemical reactions
Thermal stability is
Ability of water to absorb heat without changing much in temperature
What is a solution?
A mix of solute combined with a more abundant substance, solvent
What are colloids?
Mixtures of protein and water
What are the properties of colloids?
Medium size particles, permanently mixed, opaque
What are suspensions?
Mixes with really big particles that can’t remain mixed, can’t penetrate membranes either. Cloudy or opaque, separates upon standing
What are suspensions?
Mixes with really big particles that can’t remain mixed, can’t penetrate membranes either. Cloudy or opaque, separates upon standing
What is an emulsion?
A suspension of one liquid in another
What is an acid?
Something that releases H+
What is a base?
Something that accepts H+
What is pH?
A measure of the molarity of H+
What multiple does one full number on the pH scale represent?
A tenfold change in H+ concentration. Ex: pH 4.0 is 10x more acidic than 5.0
What are buffers?
Solutions that resist changes in pH
What is metabolism?
All chemical reactions of the body
What is catabolism?
Energy-releasing decomposition reactions. Breaks covalent bonds and produces smaller molecules
What is anabolism?
Energy-storing synthesis reactions. Requires energy input, used for production of protein or fat
What is organic chemistry?
The study of compounds containing carbon
4 categories of carbon compounds?
Carbohydrates, lipids, proteins, nucleic acids
What is a macromolecule?
A very large organic molecule with high molecular weight
What is a polymer?
A macromolecule made of a repetitive series of identical or similar subunits (monomers)
What is polymerization?
Joining monomers to form a polymer
What is dehydration synthesis?
Removing water to bind monomers together to form a polymer
What is hydrolysis?
Adding water to break polymers into monomers
3 important monosaccharides?
Glucose, galactose, and fructose
3 important disaccharides?
Sucrose, lactose, maltose
3 important polysaccharides?
Glycogen, amylose, cellulose
What are carbs used for?
A quick source of energy
Are carbs hydrophobic or hydrophilic?
Hydrophilic
Are lipids hydrophobic or hydrophilic?
Hydrophobic
5 types of lipids in humans?
Fatty acids, triglycerides, phospholipids, eicosanoids, steroids
Is “good” cholesterol high or low density?
High density
What are proteins?
A polymer of amino acids
What is a peptide?
Any molecule composed of 2 or more amino acids joined by peptide bonds
What are peptide bonds?
Bonds that join the amino group of one amino acid to the carboxyl group of the next, formed by dehydration synthesis
Polypeptides have how many amino acids?
15+
Proteins have how many amino acids?
50+
What is conformation?
Unique, 3D shape of protein crucial to function
What is denaturation?
Extreme conformational change that destroys function. Extreme heat or pH
What is primary structure?
Protein’s sequence of amino acids which is encoded in the genes
What is secondary structure?
Coiled or folded shape held together by hydrogen bonds
What are the functions of proteins?
Structure, communication, membrane transport, catalysis, recognition and protection, movement, cell adhesion
What are enzymes?
Proteins that function as biological catalusts
What is substrate?
Substance enzyme acts upon
What is activation energy?
Energy needed to get reaction started. Enzymes can lower this
What are 3 components of nucleotides?
Nitrogenous base, sugar, phosphate group(s)
BWhat are the types of nucleotides?
ATP, DNA, RNA
What is glucose?
Blood sugar
What is galactose?
Sugar made by breaking down milk
What is fructose?
Fruit sugar
What is sucrose?
Table sugar
What is lactose?
The sugar in milk
What is maltose?
Grain products
What is glycogen?
Made by humans, used for energy storage between meals
What is cellulose?
Starch, made by plants and helps us digest although we can’t digest it
Where are glycolipids?
External surface of cell membrane
Where are glycoproteins?
External surface of cell membrane, mucus of respiratory and digestive tracts
What are proteoglycans?
Type of carb, bound to protein, holds cells and tissues together and used for joint lubrication
What is a saturated fat?
It holds as much hydrogen as possible
What is an unsaturated fat?
Could hold more hydrogen
What lipid is essential for the cell membrane?
Phospholipids
What are eicosanoids?
Lipids that help w/ signaling info, blood clotting, hormone action, labor contractions, and controlling blood vessels
What are steroids?
A type of lipid which is important for nervous system function and structural integrity of cell membranes
What are peptides?
Molecules made of amino acids and joined by peptide bonds
What is conformation?
3D shape of protein crucial to function. Can change to help function
What is denaturation?
Extreme conformational change that destroys the function of a protein
Function of proteins?
Structure, communication, membrane transport, catalysis, recognition and protection, movements, cell adhesion
What are enzymes?
Proteins that enable biochemical reactions to occur. Named for the substrate w/ -ase as a suffix
How does enzyme action work?
The substrate approaches the active site of the enzyme, fits in, gets broken down, and leaves. Super duper fast
What are nucleotides made of?
Sugar, nitrogenous base, and phosphate group(s)
What are proteins made of?
Amino acids
