Deck 3: The Chemistry of Organic Molecules

Question 1

Which of the following are structural carbohydrate molecules?

A) starch and glycogen
B) starch and cellulose
C) glycogen and cellulose
D) cellulose and chitin
E) glycogen and chitin

Answer 1

D

Question 2

A lipid is a polymer made up of which kind of monomers?

A) glucose or modified glucose molecules
B) amino acids
C) nucleotides
D) alternating sugar and phosphate groups
E) fatty acids and glycerol

Answer 2

E

Question 3

The differences between organic and inorganic molecules do not follow simple absolute rules. However, most organic molecules are associated with living organisms. Which of the following statements does NOT correspond to the general distinctions between these types of molecules?

A) Carbon dioxide (CO₂) lacks hydrogen atoms found in organic molecules.
B) Formaldehyde (CH₂O) is a small molecule compared to most organic molecules.
C) Salt (Na⁺Cl^-) is not an organic molecule but is important to the life of many organisms.
D) Because they are in living organisms, organic carbon atoms are different from the inorganic carbon atoms forming the molecular structure of soot or a diamond.

Answer 3

D

Question 4

What is the molecular formula of these molecules? How do these molecules differ? Are these the same molecule?

Question 5

A hydrocarbon is hydrophobic

A) at all times.
B) only in the living cell environment.
C) except when it has an attached ionized functional group.
D) in carbohydrates but not in lipids.

Question 6

Identify the following molecule:

A) amino acid
B) hydrocarbon
C) carbohydrate
D) alcohol
E) cholesterol

Question 7

A dehydration reaction can also be called a (an) _________ reaction since it forms water.

A) condensation
B) hydrolysis
C) isomeric
D) an energy-releasing
E) monomer formation

Question 8

Which of the following carbohydrates would NOT be a molecule used for energy storage?

A) starch
B) cellulose
C) glycogen
D) All of the above are used for energy storage

Question 9

Glucose (C₆H₁₂O₆) can exist as both an open-chain form and a closed-ring form. Before 1900, glucose was only thought to occur as an open chain. Now we know that over 99 percent of the time, glucose occurs in the closed-ring form. What possible difference between these forms would give chemists a clue that the open-chain form was not present?

A) Open-chain molecules can form polymers and glucose does not.
B) Only open-chain forms can undergo condensation, which does not occur with glucose.
C) An open chain presents ends with functional groups (in this case aldehyde), and glucose failed to undergo typical aldehyde reactions; a phenomenon that could be explained by having no end functional group in a ring structure.
D) Because glucose is solid at room temperature, it must have saturated hydrocarbon chains.
E) Glucose could not be "denatured" so it must be a tight chain.

Question 10

Which functional group will attach to a hydrocarbon chain to form alcohol?

A) hydroxyl
B) carbonyl
C) carboxyl
D) amino
E) phosphate

Question 11

A polysaccharide is a polymer made up of which kind of monomers?

A) simple sugars
B) amino acids
C) nucleotides
D) alternating sugar and phosphate groups
E) fatty acids and glycerol

Question 12

What is the molecular formula for 5 glucose molecules?

A) C₃₀H₅₀O₂₅
B) C₃₀H₆₀O₃₀
C) C₃₀H₅₂O₂₆
D) C₆H₂₄O₁₂

Question 13

Which carbohydrate is found in the cell walls of plants?

A) starch
B) chitin
C) cellulose
D) glycogen
E) glycerol

Question 14

Organic molecules are those that contain at least

A) carbon.
B) carbon and oxygen.
C) carbon and hydrogen.
D) carbon, oxygen, and hydrogen.

Question 15

Which carbohydrate is used in the liver for energy storage?

A) starch
B) chitin
C) cellulose
D) glycogen
E) glycerol

Question 16

What term is used for molecules that have identical molecular formulas but the atoms in each molecule are arranged differently?

A) isotope
B) isomer
C) homomolecules
D) organic
E) balanced

Question 17

Which carbohydrate is found in the exoskeleton of insects and crabs?

A) starch
B) chitin
C) cellulose
D) glycogen
E) glycerol

Question 18

Identify this molecule:

A) amino acid
B) hydrocarbon
C) carbohydrate
D) alcohol
E) lipid

Question 19

Saturated fatty acids and unsaturated fatty acids differ in

A) the number of carbon-to-carbon bonds.
B) the consistency at room temperature.
C) the number of hydrogen atoms present.
D) all of the choices are differences between saturated and unsaturated fatty acid.

Question 20

The lipids of the cell membrane and the lipids found in butter and vegetable oil differ in which of the following?

A) the number of fatty acids attached to the glycerol molecule
B) the glycerol molecule
C) the carbon to carbon bonds
D) lipids of the cell membrane do not have hydrophobic sections of the molecule

Question 21

Which statement is true about RNA?

A) It contains adenine paired to thymine.
B) One of the bases from DNA is replaced by uracil.
C) It contains the sugar deoxyribose.
D) Its nucleotides contain twice as many phosphate groups as DNA's nucleotides.
E) It is a double-stranded molecule.

Question 22

If an animal needed to store energy for long-term use, but not be encumbered with the weight of extra tissue, which is the best molecule for storage?

A) fructose and glucose in the form of honey
B) high-calorie fat molecules
C) complex cellulose molecules
D) starch
E) glycogen with extensive side branches of glucose

Question 23

A polypeptide has an amino acid sequence of: alanine-leucine-tryptophane-glycien-valine-alanine.
This chain of amino acids is further organized into a helix that in-turn, folds in and around itself to form a globular structure. The primary structure of this polypeptide is

A) globular.
B) pleated-sheet.
C) alpha helix.
D) alanine-leucine-tryptophane-glycien-valine-alanine.

Question 24

Which Figure is that of an unsaturated fat?

A) Figure A
B) Figure B Figure A is an unsaturated fat. It has double bonds between the some of the carbon atoms. Figure B is a saturated fat with all single bonds between the carbon atoms.

Question 25

Which of these statements is NOT true about DNA?

A) It is the genetic material of the cell.
B) It forms a double helix.
C) Adenine pairs with thymine and guanine pairs with cytosine.
D) It contains the sugar ribose.
E) The sugar and phosphate groups form the backbone of the molecule.

Question 26

A peptide bond is found in which type of biological molecule?

A) carbohydrate
B) lipid
C) nucleic acid
D) protein

Question 27

Construct a portion of cell membrane using the typical phospholipid symbol. Indicate the location of the cytoplasm and outside of the cell. Explain how the chemical characteristics of phospholipids molecules dictate membrane structure and cause it to be fluid in nature.

Question 28

Fish sperm is composed mostly of the male fish's DNA. If we tested a sample chemically, we should find relatively high amounts of

A) nitrogenous bases, sugar, and phosphate groups.
B) phospholipids and steroids.
C) amino acids and unsaturated fats.
D) triglycerides and ATP.
E) globular proteins and stored fats.

Question 29

Below freezing and above boiling, cells are unable to function as "liquid machinery." However, most organisms' cells are still limited from functioning throughout this full range of liquid temperatures. At the molecular level in different organisms, cells' ability to vary in their tolerance to temperature, etc., is most closely related to variation in

A) enzyme activity and protein denaturation.
B) ATP efficiency.
C) ability to form glucose polymers.
D) replication of nucleic acids.
E) extent of saturation of fatty acids.

Question 30

If a segment of DNA has 20% adenine in its base composition, what percent thymine is there?

A) 20%
B) 80%
C) 60%
D) 30%

Question 31

The reactivity of an organic molecule is primarily dependent upon ____________ of the molecule.

A) the carbon skeleton
B) the attached functional groups such as a hydroxyl group
C) the isomer
D) All of the choices are correct.

Question 32

Choose the Figure that depicts polymer synthesis.

A) Figure 1
B) Figure 2 Figure 2 depicts a polymer being hydrolyzed. In degradation, the monomers in a polymer separate during a hydrolysis reaction. A bond is broken as water is added.

Question 33

Do disaccharide isomers exist? If so, describe how they are formed.

Question 34

How many molecules of water are used to degrade this polypeptide, using hydrolysis reactions, into its constituent amino acids: alanine-leucine-tryptophane-glycine-valine-alanine?

A) six
B) five
C) one
D) seven

Question 35

The alpha helix and beta sheet are found at which level of protein organization?

A) primary structure
B) secondary structure
C) tertiary structure
D) quaternary structure

Question 36

A strand of DNA has the following base sequence (genetic code): ATTGCGAATGGCA. Construct the complementary strand of DNA.

Question 37

A saturated fat

A) is often solid at room temperature.
B) has fatty acids with no double bonds between the carbon atoms.
C) is of animal origin.
D) All of the choices are correct.

Question 38

After eating eggs for breakfast, you return in the evening, dunk the dirty dishes in water, and notice the yellow streaks remain "dried on." However, after soaking awhile, the complex of various egg yolk molecules easily "washes off." What has happened?

A) Heating denatured the egg protein molecules, hydrolysis reactions then formed bonds in the dried egg, and soaking in water eventually resulted in condensation reactions where water broke these bonds.
B) Heating denatured the egg protein molecules, unorganized condensation reactions then formed bonds in the drying egg, and soaking in water eventually resulted in hydrolysis reactions where water broke these bonds.
C) The egg monomers were fused to become one polymer, which was easily dissolved by water back into monomers.
D) The presence or absence of water changes the molecules from hydrophilic to hydrophobic respectively.
E) The addition of water converted organic molecules into inorganic molecules.

Question 39

The feet of penguins and reindeer contain large amounts of unsaturated triglycerides. Why would these animals have these fats in their feet rather than saturated fats?

Question 40

Chitin and cellulose are molecules that do not spontaneously break down but can be digested by bacteria and some other microorganisms. Since carbon is not among the most common elements in the earth's crust, what would happen if all of the chitin-digesting and cellulose-digesting organisms on the earth were destroyed?

Question 41

Carbon can form covalent bonds with as many as four other atoms.

Question 42

Which of the following is a function of a steroid?

A) sex hormone
B) transmission of genetic information
C) long term energy storage
D) insulation against cold
E) protective layer

Question 43

Which of the following protein is correctly matched with its function?

A) hemoglobin is found within the red blood cells
B) myosin is found within the ligaments
C) actin is found within the tendons
D) collagen is found within the muscle cells
E) hemoglobin is found within the cell membrane

Question 44

Starch is a protein that serves in energy storage in plant cells.

Question 45

ATP is a protein that supplies energy to the cell.

Question 46

Which of the following protein structures is exemplified by globular proteins?

A) tertiary
B) secondary
C) primary
D) quaternary
E) all of the protein structures are exemplified by globular proteins

Question 47

If a certain segment of DNA has 30% adenine in its base composition, what percentage of guanine will there be? ev: 10_30_2013_QC_37868

Question 48

Due to an increased risk of heart disease many doctors have suggested shifting our diet to include more oils instead of fats. As you cook dinner tonight the recipe calls for 2 tbs of oil. What is the most likely source of the oil you should use in preparing your meal?

A) canola or olives
B) bees wax distilled down to an oil form
C) melted butter
D) lard that was left out at room temperature
E) none of these choices are oils

Question 49

What are the basic structures that make up a nucleotide?

A) pentose sugar, phosphate and nitrogen-containing base
B) pentose sugar, nitrate and phosphorus-containing base
C) ribose sugar, phosphate and nitrogen-containing base
D) hydroxide group, phosphate and nitrogen-containing base
E) pentose sugar, sodium and nitrogen-containing base

Question 50

Migratory birds store energy as glycogen which is lighter than fat.

Question 51

Which of the following structures is classified as a nucleic acid?

A) adenine
B) RNA
C) thymine
D) guanine
E) cytosine

Question 52

Waxes consist of a glycerol bonded to three long-chain fatty acids.

Question 53

Which of the following functional groups represents sulfhydryl?

A) SH
B) H-N-H
C) OH
D) 0=C-OH
E) C=O

Question 54

Which of the following is NOT a protein function?

A) support
B) transportation
C) defense
D) motion
E) insulation

Question 55

Which statement below correctly describes why ATP is a high energy structure?

A) ATP contains 2 phosphate bonds that contain high levels of energy.
B) ATP contains hydro-carbon chains that hold energy.
C) ATP is composed of thymine which is a high energy molecule.
D) The last two phosphate bonds are unstable and easily broken.
E) The first phosphate bond is unstable and easily broken.