Introduction to Biology and Chemistry: Exam Review and Key Concepts
Exam 1
DNA and RNA
DNA: A G T C
RNA: U C A G
Organic Molecules and Polymers
Most pesticides are organic molecules.
True or False: All cell walls are made of carbohydrates. True
True or False: All biomolecules are polymers. False
Redox Reactions and Electricity
True or False: A battery uses redox reactions to generate electricity. True
True or False: Oxidation and reduction have to happen together. True
True or False: The term “organic” when referring to molecules means they are not harmful. False
Review Questions
- True or False: A theory can be changed. True
- True or False: An element cannot be broken down to simpler substances. True
- True or False: When 50 pounds of wood is burned and there is left over 5 pounds of ash, the other 45 pounds turned into energy. False
- True or False: In a solid, the particles can move past each other. False
- True or False: In a chemical change, new substances are formed. True
- A gas fills its container while a liquid does not because: Liquid particles interact while gas particles do not.
- Circle the elements below: todos los de la tabla periodica (All of the elements on the periodic table)
- Ions are: atoms of the same element with different numbers of electrons.
- Metals: All of the above.
- Which of the following should have the highest attraction for electrons? Oxygen
- In a covalent bond: electrons are shared.
- Which of the following is the major component of air? Nitrogen
- What are VOC’s? Volatile Organic Compounds
- What is an aerosol? Small drops of liquid floating in a gas.
- All of the following are part of the electromagnetic spectrum except: Heat
- Ozone protects us from: Ultraviolet radiation.
- What is a cause of ozone depletion? All of the above.
- Which of the following are greenhouse gases? a. CH4 b. H2O d. CO2
- Which part of the electromagnetic spectrum is responsible for global warming? Infrared
- Climate data from many years ago is determined from: Ice core data
- For each of the following, give the number of protons, neutrons, and electrons.
P n e a. 64Cu 29 35 29 b. 24Mg2+ 12 12 10 - For each of the following, indicate how many of each type of atom.
- a. C6H12O6 C: 6, H: 12, O: 6
- b. Al2(SO4)3 Al: 2, S: 3, O: 12
- Balance each of the following equations.
- a. 4 Fe + 3 O2 –> 2 Fe2O3
- b. 2 C4H10 + 13 O2 —> 8 CO2 + 10 H2O
- For each of the following, draw a Lewis dot structure and give the shape.
- a. CCl2F2 Tetrahedral
- b. O3 Bent
- We had a reading assignment regarding vaccines. There is a growing number of people choosing not to vaccinate their children. Why are they opting out of vaccines? Are the worries of these people backed by data?
Most are concerned about the purported link between vaccines and autism, which is not true. Others are concerned about possible side effects which, though real, are extremely rare.
- As more and more people “opt out” of vaccines, what is the concern? Is there evidence that this “concern” might be taking place?
The concern is the spreading of previously eradicated diseases which IS happening as we are having epidemics of measles and whooping cough.
Exam 2
Fossil Fuels and Electricity Generation
True or False: With modern technology, we can actually get more energy out of a fossil fuel than the potential energy stored in it. False
True or False: Most electricity is generated by heating water to turn turbines which generate electricity. True
True or False: Electromagnetic radiation and radioactivity are the same thing. False
Nuclear Power and Renewable Energy
True or False: An advantage of nuclear power is there are no greenhouse gases formed. True
True or False: Bottled water is significantly safer to drink than tap water. False
All electricity is generated by turning turbines except: Solar energy.
A disadvantage to solar energy as a source of electricity is: Solar panels are expensive.
The term “renewable energy” means: We can make more.
Ionizing Radiation and Radioactivity
Ionizing radiation is: Radiation that can remove electrons from atoms.
Which of the following is most ionizing? a. Alpha particles
Which of the following is most penetrating? Gamma rays
The equation E = mc2 means: That a small amount of matter turns into a large amount of energy.
If the half-life of 14C is 6000 years, if a sample originally had 5.0g of 14C and it now has 0.625g, how old is it? 18000 years old
Radioactivity is: Disintegration of the nucleus of an atom.
Fill in the blank: 21283Bi → 42He + 20881Tl
Water Properties and Importance
Water is important in the body because: All of these.
Which of the following are odd properties of water? (more than one answer): a. The solid is less dense than the liquid. b. It has a high boiling point for a molecule of its size.
Which of the following is/are (an) intermolecular force(s)? b. Hydrogen bond c. Dipole-dipole
In chemistry, if you are not told otherwise, the solvent is: a. Water
Which of the following are methods to make water safe to drink? All of the above.
Chemical Nomenclature and Formulas
Fill in the blanks.
| Name | Formula |
|---|---|
| Calcium bromide | CaBr2 |
| Aluminum oxide | Al2O3 |
| Potassium sulfate | K2SO4 |
| Strontium nitrate | Sr(NO3)2 |
| Dinitrogen trisulfide | N2S3 |
| Phosphorus pentabromide | PBr5 |
What does “like dissolves like” mean? Polar solutes dissolve in polar solvents and nonpolar solutes dissolve in nonpolar solvents.
Draw a diagram of a soap dissolving oil. Be sure to show the polar and nonpolar ends of the soap molecule. (Image Placeholder: 
)
Nonpolar part of soap dissolves in oil (nonpolar). Polar part dissolves in water and oil gets pulled apart.
Specific Heat and Global Climate
Water has an extremely high specific heat. What is specific heat? What is the importance of the specific heat of water to global climate?
Specific heat is the amount of heat required to raise the temperature of 1 g of a substance 1 degree Celsius. It makes water an excellent insulator so it holds heat in.
Overprescription of Drugs
We had a reading assignment about the use of Ritalin for ADD and ADHD and then got into a discussion about overprescription of drugs. What is overprescription of drugs? Why is it a problem?
Overprescription of drugs is giving either too many prescriptions or unnecessary prescriptions. The problem is that many times we are using drugs as an “easy fix” for problems that really should be solved differently. Drugs fix the symptom, but not the actual problem.
Exam 3
Oxidation-Reduction Reactions
True or False: Oxidation and reduction have to happen together. True
True or False: A battery uses redox reactions to generate electricity. True
True or False: The term “organic” when referring to molecules means they are not harmful. False
Biomolecules and Polymers
True or False: All biomolecules are polymers. False
True or False: All cell walls are made of carbohydrates. True
Reaction Analysis
Reaction: Cu + 2 AgNO3 —-> Cu(NO3)2 + 2 Ag
Which element is being oxidized? a. Cu
Which element is being reduced? Ag
What is the role of the nitrate ion? Balances charge.
What is the role of the salt bridge? Keeps the reaction running.
Batteries and Energy Storage
A major issue with batteries as far as energy storage is: All of the above.
Organic Chemistry and Functional Groups
In organic chemistry, a functional group refers to: The non-carbon part.
Which of the following is an alcohol? e. ROH
Which of the following is an amine? RNH2
Which of the following is an aldehyde? RCHO
Which of the following is a thiol? RSH
Polymers and Information Transfer
Proteins are a polymer of: a. Amino acids
Starch is a polymer of: b. Monosaccharides
Cellulose is a polymer of: Monosaccharides
DNA is a polymer of: Nucleotides
Information transfer goes in the following order: d. DNA —-> RNA —-> Protein
Understanding “Organic”
The word “organic” means different things to different people. What does it mean to a consumer? Naturally grown or harvested without hormones, pesticides, etc.
What does it mean to a chemist? A molecule based on carbon or containing mostly covalent bonds.
Stereospecificity
What is stereospecificity? Why is it important? When something binds to a specific stereoisomer. It makes for very specific binding.
Amphipathic Molecules
What does “amphipathic” mean? What type of biomolecule is typically amphipathic?
Has polar and nonpolar parts. Lipids.
DNA, RNA, and Amino Acid Sequences
For the DNA sequence below: 3′ TCT TAG CCT GTA TGC 5′
AGA AUC GGA CAU ACG
R I G H T
a. Determine the RNA sequence.
b. Using the Genetic Code and the one-letter abbreviations for the amino acids, determine the amino acid sequence.
Polymers and Plastics
A polymer is: A repeating unit of monomers.
To decrease the amount of plastics in landfills, we should do which of the following: d. All of the above.
Nutrition and Diet
The order in which nutrients are burned is: Sugar, starch, fat, protein.
Most diets don’t work because: People don’t stick to them.
Water Importance and Properties
Water is important in the body because: All of these.
Which of the following will likely dissolve in water? (more than one answer) CaBr2, c. CH3CH2OH
Which of the following are methods to make water safe to drink? All of the above.
Chemical Nomenclature
The name for Al2O3 is: Aluminum oxide.
The formula for diphosphorus pentoxide is: P2O5
Environmental Concerns
Which of the following are contributors to ozone depletion? Deforestation, CFS.
Which of the following is NOT a consequence of global warming? Increased sunburn.
The following atom 18O contains: 8 protons, 10 neutrons, and 8 electrons.
Global warming is: Very real and backed by data.
Which of the following generates greenhouse gas? Use of coal to fuel a power plant.
Energy Sources and Concerns
A major problem with oil as an energy source is:
- a. It is polluting.
- b. It increases global warming.
- c. It is not renewable.
In a nuclear power plant, radiation is: a. Used to heat water to turn turbines.
Which of the following caused most of the problems with the nuclear power plants in Japan recently? Lack of ability to cool reactors and keep waste underwater.