Experimental Design
What are control, independent, and dependent variables?
Control variables stay constant. The independent variable is what the experimenter changes, and the dependent variable is what the experimenter measures in response to the change in the independent variable.
How many subatomic particles, and of what types, are in an atom of Carbon-12?
6 protons
6 neutrons
Name the four categories of biological macromolecules.
Proteins, Lipids, Carbohydrates, Nucleic Acids
What type of macromolecule is glucose?
A carbohydrate.
What is the Panspermia Hypothesis?
The hypothesis that organic molecules originated somewhere other than Earth and were brought by meteorites.
What is the difference between a hypothesis and a theory?
A hypothesis is a testable idea. A theory is an explanation for an observed phenomenon that is well-supported by a wealth of evidence.
What is the difference between an isotope and an isomer?
Isomer: same atoms arranged differently in a molecule
Isotope: different number of neutrons in the nucleus of an atom of the same element
Which category of biological macromolecules is not polymerized?
Lipids
What is denaturation, and what is at least one thing that can cause it?
Denaturation is when a protein loses its shape and thus its function. It can be cause by factors such as temperature, pH, salt, or oxidation/reduction.
What are coacervates and liposomes?
Two types of early boundaried structures that may have been precursors to cells.
An experiment was carried out to test the effects of radiation on mice using three groups of mice
of the same age, gender, and physical features. The mice in the first two groups were exposed to
radiation at two different distances, while the mice in the third group did not receive any
radiation. Are these groups control or experimental?
Both radiation groups are experimental groups, while the group that received no radiation is a control group.
Suppose you have a trimer and you would like to make monomers. What kind of reaction will you need to do, and what other molecules, if any, will be required?
Will need to do hydrolysis, which requires water.
What is the difference between a saturated fat and an unsaturated fat?
Unsaturated fats have double bonds in their fatty acid chains, while saturated fats do not.
Why do plants need both starch and cellulose?
Starch is used by plants for energy storage, while cellulose provides plants with structure.
What kind of a surface did polymerization of early organic molecules require? Why?
A clay surface was most likely required because in an aqueous environment hydrolysis would be competing with polymerization.
If all green plants require sunlight for photosynthesis, then any green plant placed in the dark would not synthesize glucose, the end product of photosynthesis. Is this reasoning deductive or inductive?
Deductive, since it applies a general principle to a specific instance.
Name four properties of water and why they are important for life on Earth.
cohesion, adhesion, high heat capacity, high heat of vaporization, solid less dense than liquid, universal solvent
What is the monomer for nucleic acids, and what are the three components of that monomer?
Nucleotides, which are made up of a sugar, a phosphate group, and a nitrogenous base.
Give at least three structural differences between DNA and RNA.
RNA is single stranded, has uracil instead of thymine, and contains ribose vs. deoxyribose
What are the four stages of chemical evolution?
2. Polymerization
3. Formation of boundaries
4. RNA world
What are some things that make a good graph? Suppose you have some plant height over time data you would like to graph. Draw an example of a good graph and an example of a graph that looks ok but would be misleading or hard to understand.
Good graphs put the independent variable on the x-axis and the dependent variable on the y-axis. They include clear labeling and a scale for each axis that makes sense. They clearly indicate what the lines on the graph mean and provide any other important contextual information.
Suppose you have a beaker with a solution with pH 2 and another beaker with a solution of pH 11. Which is more acidic? Draw each beaker with the appropriate pH relative to each other (it doesn't have to be exact), using H+ to indicate protons.
pH 2 is more acidic and will have many more protons in it
Draw a phospholipid bilayer. What areas are hydrophobic and what areas are hydrophilic? Why is the amphipathic nature of the bilayer important?
Hydrophilic on the outsides, hydrophobic in the middle. This helps the cell control what comes in and out.
What are the four levels of protein structure? Draw a simplified model of each of them (you may need multiple colors).
Primary: amino acid sequence
Secondary: alpha helices and beta sheets
Tertiary: three dimensional folding
Quaternary: multiple amino acid chains folded together
What is endosymbiotic theory? Draw a picture of the basic process involved in this theory.
Endosymbiotic theory explains the origin of mitochondria and chloroplasts. It involves early bacteria engulfing other early bacteria and them becoming dependent on each other and eventually one organism (over evolutionary time).