Science of Biology
What are the three domains of life?
Name the six atoms that make up >96% of a cell's biomass (living matter).
Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorus, Sulfur
What is the monomer that makes up a protein polymer?
amino acid
What is the difference between a triose sugar and a pentose sugar?
The number of carbon atoms (3 vs. 5)
Name one factor that affects the cell membrane's permeability.
molecule size and polarity/charge, length of fatty acid tails, number of unsaturated vs. saturated tails, amount of cholesterol in the membrane
What was Darwin's & Wallace's major contribution to modern biology?
Natural selection as a mechanism for evolution
What is the defining characteristic of an atom?
Which nucleotides bond together in complementary base pairing of DNA?
Adenine bonds with thymine, and guanine bonds with cytosine
What is the distinguishing characteristic of the lipid biomolecule class?
Lipids are mostly nonpolar (hydrophobic).
What type of transport involves molecules moving spontaneously down a concentration gradient?
Passive transport (diffusion)
What two hypotheses did Louis Pasteur test, using a straight-necked flask and a swan-necked flask?
1. Cells arise from spontaneous generation.
2. Cells arise from pre-existing cells.
What type of bond forms when electrons are shared between atoms but the charge is distributed unequally across the molecule?
polar covalent
Describe the secondary structure of a protein.
Of the types of lipids we discussed, which are signaling molecules that aid in cell communication?
Steroids
The bulk transport of materials out of a cell is called _____.
exocytosis
What are the three components of Cell Theory?
1. The cell is the basic unit of structure.
2. All organisms consist of a cell or cells.
3. All cells arise from pre-existing cells.
_____ reactions break down polymers into monomers, and _____ reactions synthesize polymers from monomers.
Hydrolytic (hydrolysis), condensation
What determines the shape of a functional protein?
The primary structure - the amino acid sequence of the polypeptide
What characteristic of carbohydrates and fats make them excellent energy-storage molecules?
The large number of C-C and C-H bonds
What is required for active transport?
Name two factors that must be present in a population for natural selection to act (upon the population).
Variation in traits
Traits are heritable
More offspring are born than can survive
What makes an atom reactive?
A valence orbital (shell) that is not filled, aka missing or unpaired valence electrons
Nucleic acid has directionality - one end has a(n) _____ bonded to the 5' carbon, and the other end has a(n) _____ bonded to the 3' carbon.
phosphate group; hydroxyl group
Why can we digest the carbohydrate starch, but not the carbohydrate cellulose?
We lack the enzyme needed to break beta-glycosidic linkages of cellulose.
You place a cell in a hypotonic solution. Describe the relative solute concentrations inside and outside the cell, and state whether the cell will shrink as it loses water or swell as it takes on water.
Higher solute concentration inside the cell, compared to the outside. The cell will swell as water diffuses into the cell.