Download Unit 3 Review Sheet – Biochemistry

Unit 2 Review Sheet – Biochemistry
Basic Chemistry
What are protons, neutrons and electrons?
Protons are positively charges, neutrons have no charge and electrons have a
negative charge. Protons and neutrons are in the nucleus and the electrons are in
a cloud around the nucleus
What is the difference between an atom, an ion and an isotope?
Atom is typically uncharged. Ion is the charged version of that atom. An isotope is
the atom with a non-typical number of neutrons
What are the three main bond types? Describe them
Covalent bonds: strongest, shared electrons, common in carbon bonds
Ionic bonds: weaker than covalent, attraction between positive and negative
bonds, common in salts, acids and bases
Hydrogen bonds: weakest, attraction between partial positive and partial negative,
common in water and DNA
pH
What are the measurements of the pH scale?
pH scale measures the acidity of a solution by measuring the concentration of H+
(hydrogen ions) on a scale of 0-14
Which end is acid? Which is base? What is neutral?
Low numbers are acidic, high numbers are basic, 7 is neutral
Water
What are the characteristics of water that make it important to life?
Polar, high heat capacity, resists temperature change, abililty to bond and attract
other molecules (cohesion and adhesion), ice is less dense than liquid water,
universal solvent, most abundant compound in living things
What does it mean that water is polar?
There is a partial positive charge in one part of the molecules (the hydrogen
atoms) and a partial negative charge in another part (the oxygen). This is because
of unequal electron sharing.
Explain the bonding within and between water molecules.
The bonds between hydrogen and oxygen atoms IN ONE water molecule are
covalent bonds. The bonding between two separate water molecules is hydrogen
bonding, because of the attraction between the partial positive and negative
charges.
Macromolecules
What is the difference in organic and inorganic molecules?
Organic molecules contain carbon
How many bonds does carbon typically form? What type of bond are they?
4 bonds; covalent
What are the 4 organic molecules and the monomer (subunit) of each?
1. Carbohydrate Monomer: monosaccharide (single sugar)
2. Lipid
Monomer: fatty acids and glycerol
3. Protein
Monomer: amino acid (this is on tests and SOLs a lot)
4. Nucleic Acids Monomer: nucleotide
What is the purpose of each of the macromolecules?
1. Carbohydrate Quick energy
2. Lipid
Long term energy storage
3. Protein
Structure, action, ENZYMES
4. Nucleic Acids Information storage
What is the difference in a monosaccharide, disaccharide, and polysaccharide?
Monosaccharide is a single sugar, disaccharide is made of two monosaccharides
and a polysaccharide is made of many monosaccharides
What are some examples of each of the 4 macromolecules?
1. Carbohydrate Glucose, fructose (mono); sucrose (di); starch, glycogen (poly)
2. Lipid
Fats, oils, waxes, steroids, cholesterol
3. Protein
Hemoglobin (in blood), enzymes, structural in fingernails
4. Nucleic Acids DNA, RNA (NA= nucleic acid)
Enzymes
Define catalyst
Something that speeds up a chemical reaction without being used up
What are 2 things that can change the rate of enzyme reaction?
High temperature and extreme pH because they denature the enzyme (make it not
work)
What is the difference in the active site and the substrate?
The substrate is what the enzyme is acting on and the active site is the place of
the enzyme that is shaped so the substrate can fit
What does the “lock and key” feature of enzymes indicate?
The active site is shaped so it perfectly fits the substrate, just like a key is
perfectly shaped for the lock it opens
Chemical Reactions
What is the name of the reaction in which macromolecules are put together?
Dehydration synthesis
What is the name of the reaction in which macromolecules are broken apart?
Hydrolysis
Which reaction is represented by the formula:
Sugar + sugar + sugar  polysaccharide + water
It is Dehydration synthesis because sugars are the reactants (on the left side) and
a polysaccharide is the product (on the right side) and water is a product as well.
This means that monomers are being put together and water is taken out.