/ The following functional group is a. Aldehyde c. Carboxyl b. Ketone d. Amino

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1 Section A: Multiple Choice Select the answer that best answers the following questions. Please write your selected choice on the line provided, in addition to circling the answer. /25 1. The following functional group is a. Aldehyde c. Carboxyl b. Ketone d. Amino 2. The following functional group is a. Phosphate c. Sulfhydryl b. Hydroxyl d. Amino 3. The following molecule contains which of the following functional groups a. Amino, carboxyl c. Amino, ketone b. Amino, aldehyde d. Amino, hydroxyl 4. The following molecule is a. Fructose c. Alpha-glucose b. Ribose d. Beta-glucose 5. The following molecule is a. Maltose c. Lactose b. Sucrose d. Glycogen 6. The following molecule is a. Saturated fatty acid c. Steroid b. Unsaturated fatty acid d. Wax 7. The following molecule is an example of a. A pyrimidine c. A phosphate group b. A purine d. Deoxyribose 8. The following molecule is a. Saturated fatty acid c. Triglyceride b. Unsaturated fatty acid d. Steroid 1

2 9. Which of the following statements describes the secondary structure of proteins? a. It is the unique linear sequence of amino acids in the polypeptide chain b. The polypeptide folds into beta-pleated or coils into alpha-helix c. When intermolecular reactions result in the 3D shape of the protein d. When two or more polypeptides form a functional protein 10. Which of the following is true about a protein and starch? a. Both contain nitrogen c. Both contain a carboxyl group b. Both are polymers d. Both are synthesized in animals 11. A nucleotide consists of three parts, which of the following statements is true? a. Phosphate group, sugar, nitrogenous base b. Amino group, R group, carboxyl group c. Phosphate group, sugar, amino group d. Phosphate group, glucose, nitrogenous base 12. Which of the following statements about mitochondria is false? a. Specializes in making ATP b. They are the powerhouse of the cell c. Make and store chlorophyll d. Surrounded by a double membrane 13. The following is an example of a. A hypertonic solution b. Isotonic solution c. A hypotonic solution d. A heterogeneous solution 14. Which of the following is not an example of passive membrane transport? a. Simple diffusion c. Osmosis b. Facilitated diffusion d. Pinocytosis 15. Insulin is a protein that is produced by certain pancreatic cells and secreted into the bloodstream. Which of the following choices best describes the route of insulin from its production to its exit from the cell? a. Rough ER, vesicle, cell membrane b. Rough ER, vesicle, Golgi apparatus, vesicle, cell membrane c. Smooth ER, vesicle, Golgi apparatus, vesicle, cell membrane d. Smooth ER, lysosome, vesicle, cell membrane 16. Which association is not correct? a. Nucleic acid genes c. Fats enzymes b. Carbohydrates energy storage d. Proteins cell membrane 17. Which of the following molecules synthesized by plants, most likely resembles the glycogen synthesized by animals? a. Cellulose c. Chitin b. Starch d. Glucose 18. Which of the following reactions would result in the production of water a. Breaking down a disaccharide c. Breaking down a peptide bond b. Formation of a peptide bond d. All of the above 2

3 19. Which statement regarding enzymes is false? a. Enzymes make the activation energy lower for a reaction b. Enzymes are not used up in a reaction c. Enzyme reaction rate remains the same as the [substrate] increases d. Enzyme reaction rate changes if the enzyme is denatured 20. A dipole occurs when a. Two atoms with an electronegativity difference bond b. Electrons are transferred from one atom to another c. Two atoms of the same electronegativity bond d. Electrons are shared equally between two atoms 21. Which of the following is the essential characteristic of a polar molecule? a. Contains double or triple bonds b. Is formed at extremely low temperatures c. Contains ions as part of the structure d. Has an asymmetrical distribution of electrical charge 22. The extremely large diversity of structure seen in proteins is mainly due to a. The disulfide bridge and hydrogen bonds that determine molecular shape b. The different number, kinds, and sequence of amino acids c. The different kinds of bonds between adjacent amino acids d. The ability of having two or more functioning proteins in one complex 23. Which three of the following are characteristics of hydrogen bonds? I. They are responsible for the surface tension properties of water II. They are responsible for the relatively high heat of vaporization of water III. They are formed between the elements H and N, O, or C IV. They are present in all substances V. Hydrogen bonds stabilize the two strands of a DNA helix a. III, IV, V c. I, III, IV b. I, II, V d. II, III, IV 24. Which of the following is not a function of the cell membrane? The membrane a. Has receptors for signaling c. Forms a selective barrier b. Is involved in cell identification d. Is the control center of the cell 25. Which of the following describes secondary active transport? a. When solutes move through a channel protein against the gradient b. When a lysosome digests cargo and breaks it down into smaller molecules that are useful for the cell c. When a white blood cell helps to fight infection by engulfing invading organisms or particles d. When solutes move through a channel against the gradient to provide energy for the movement of facilitated transport in the opposite direction Section B: Matching Match the term with the appropriate definition. Select the most correct answer. /15 Simple diffusion Lipid Hydrolysis reaction Hypertonic Facilitated diffusion Steroid Polymer Hypotonic Integral membrane proteins Cholesterol Allosteric regulation Exocytosis Peripheral membrane proteins Wax Polypeptide Endocytosis Carrier proteins Plastid Phosphodiester bond Hydrophilic 3

4 Channel proteins Vesicle Peptide bond Hydrophobic Induced-fit model Mitochondria Ester linkage Amino acid Endoplasmic reticulum Golgi body Glycosidic linkage Carbohydrate 1. Hydrolysis A chemical reaction in which water is used as a reactant to split larger molecules into smaller subunits 2. Hydrophilic_ Polar or charged molecules that are strongly attracted to water 3. Polymer A large molecule that is formed when monomers link together chemically in a chain 4. Glycosidic Linkage A bond between two monosaccharides 5. Phosphodiester bond_ The covalent bond holding nucleotides of a strand together 6. _Steroid_ Group of lipids with structures that are based on a framework of four fused carbon rings 7. _polypeptide_ A peptide with 50 amino acids 8. allosteric regulation _ The regulation of one site of a protein by binding to another site on the same protein 9. _peripheral membrane proteins 10. facilitated diffusion Proteins that are positions on the surface of a membrane and do not interact with the hydrophobic core of the membrane The transport of ions and polar molecules through a membrane via protein complexes down the concentration gradient 11. hypotonic The property of a solution that has a lower solute concentration than another solution 12. endoplasmic reticulum A membrane-bound organelle that is folded into flattened sacs and tubes, and is often an outgrowth of the nuclear envelope 13. plastid A membrane-bound organelle that contains enzymes and pigments that are used to perform photosynthesis 14. carbohydrate 15. cholesterol A source of energy also involved in cell-to-cell communication on the cell membrane A lipid molecule in animals, involved in regulating the fluidity of the phospholipid bilayer in the cell membrane Section C: Short Answer Please ONLY answer THREE of the following FOUR questions. You are expected to write using complete sentences. You can use diagrams in order to support your explanations. Please contain your answer to the spaces provided, writing outside of the provided space will not be marked. Only the first three answers will be marked. You will receive marks for the way you communicate your ideas and your ability to provide relevant examples. Please write neatly. Application /18 Communication /6 4

5 1. Describe the process of a dehydration synthesis reaction. What is happening during this reaction? Provide at least 2 examples, providing details for each. Why is this important? Justify your answer. [C: 6] [A:2] Dehydration synthesis reaction = producing a larger molecule by combining smaller units/monomers Via taking out a water molecule (H2O) Examples of examples: o Example 1: glucose + glucose = maltose (glycosidic linkage linked at C-1 and C-4) o Example 2: glycerol + 3 fatty acids = triglyceride (linked by ester linkages at the OH groups and carboxyl group) Important as it allows us to create polymers necessary for life o Examples: e.g. DNA from nucleotides that makes up our genetic/hereditary information; Glycogen from carbohydrate monomers that store energy; Cellulose from carbohydrate monomers that make up the cell walls that protect plants, etc. 2. What is an enzyme? Explain the importance of enzymes and include the following terms: activation energy, active site, and substrate. How does competitive inhibition and noncompetitive inhibition affect the functioning of enzymes? Justify your answer. [C: 6] [A:2] Enzyme = protein catalyst that aids in chemical reactions by lowering the required activation energy Vocabulary (be able to properly use and define these terms) = Activation energy; active site; substrate Important because enzymes are used to facilitate so many life processes (i.e. digestion, transport, etc.) Competitive inhibition = inhibitor inhibits enzyme activity by competing for the active site Noncompetitive inhibitor = inhibitor inhibits enzyme activity by binding to a different binding site; changes the conformational shape of the enzyme so that the substrate cannot bind to the active site Inhibitors affect the functioning of enzymes by reducing the rate of reaction/preventing the reaction from occurring 3. What are the different parts of the fluid mosaic model? Why is this model important in understanding the structure/function of the cell membrane? Justify your answer. [A: 6] [C:2] Examples: o Phospholipid bilayer (hydrophilic/hydrophobic components = selectively permeable membrane) o Cholesterol (fluidity; adjustments to temperature) o Proteins (Integral/peripheral membrane proteins involved with enzymatic activity, transport, etc.) o Carbohydrates/glycoproteins (involved in cell-to-cell signaling, etc.) Model demonstrates fluid nature of membrane and its ability maintain the internal environment inside the cell and be selectively permeable in regulating what enters and exits across the cell membrane 4. What is passive transport and active transport? Explain the differences between these two forms of transport and give examples of each. Why is it necessary to have both types of transport across the cell membrane? Justify your answer. [A: 6] [C:2] Passive transport = movement of molecules across the cell membrane without the use of energy o From high to low concentration o Examples: osmosis, simple diffusion, facilitated diffusion (provide more details for each) Active transport = movement of molecules across the cell membrane; requires energy o From low to high concentration o Examples: primary and secondary diffusion (provide more details for each); can also mention endo and exocytosis Important as the membrane is selectively permeable and helps to regulate the movement of things across the membrane; there are polar, non-polar, charged, big, small molecules etc. We need different types of transport to facilitate and regulate different kinds of molecules that may need to cross the membrane or be kept out 5