Portage Learning Chem 210 - FINAL exam

True or False: Nitrogen is called the superglue of the chemical world. FALSE True or False: Large elements, such as strontium, are common in biomolecules. FALSE True or False: The time it takes for a compound to flow through a metabolic pathway is called the payoff phase. FALSE True or False: Proteins, carbohydrates, and fats all get broken down into acetyl-CoA. TRUE True or False: A fat is a lipid molecule that is a solid at room temperature. TRUE In DNA, guanine always pairs with . Thymine Guanine Uracil Cytosine Both A and B CYTOSINE Water is considered a polar solvent due to attractive forces known as hydrogen bonds. A hydrogen bond is . A bond that is stronger than a covalent bond An attractive force between molecules where partially positive hydrogen atoms are attracted to partially negative atoms of F, O, or N. The polar O–H bond in water An ionic bond between H and another atom A covalent bond between H and O AN ATTRACTIVE FORCE BETWEEN MOLECULES WHERE PARTIALLY POSITIVE HYDROGEN ATOMS ARE ATTRACTED TO PARTIALLY NEGATIVE F, O, OR N Which of the following is the structure of ADP? B Water is a unique molecule. Which of the following contributes to water’s unique place in the chemical world? The geometry of the molecule The polarity of the O-H bonds The ability of water molecules to hydrogen bond The bond angle of water All of the answers are correct ALL ANSWERS ARE CORRECT Scientific Calculator The H+ concentration of a solution is 7.9 x 10-13 M. What is the pH? -6.70 6.70 11.17 -12.1 12.1 12.1 [ [H+]=7.9 x 10-13; pH=-log[7.9 x 10-13]= 12.1] Which of the following is the enthalpy change of a reaction? A) ΔG B) ΔS C) ΔH D) ΔF E) None of the above C The following is what type of protein secondary structure? Alpha helix Beta turn Parallel beta sheet Anti-parallel beta sheet Globular sheet ANTI-PARALLEL BETA SHEET A globular protein is an example of a protein . motif Conformation Secondary structure Quaternary structure Amino acid CONFORMATION Any molecule or ion that is necessary for an enzyme’s function is called a Cofactor Coreactant Coproduct Bienzyme Both B and C COFACTOR A(n) is a compound that binds to an enzyme in such a way that the enzyme slows down or stop the enzyme reactions. Ligand Substrate Inhibitor Coenzyme Deactivator INHIBITOR The following are all examples of a carbohydrate’s function in cells except . Structural role in RNA Structural role in DNA Intermediate in metabolism Basis for building proteins Energy source for cells BASIS FOR BUILDING PROTEINS The following is an example of a biomolecule. Protein Carbohydrate Lipid Nucleic acid None of the above PROTEIN Question 18 3 / 3 pts A particular lipid is a liquid at room temperature, so it is called a(n) . Oil Fat Lipid Membrane Sphingolipid OIL E The following separates life from non-life. Cellular membranes Carbohydrates that provide the necessary energy Fats that provide energy to organisms Protein transporting oxygen None of the above CELLULAR MEMBRANES The primary sequence of proteins is written . N to C C to N 5’ to 3’ 3’ to 5’ Both A and D N TO C A lipid is . A fat An oil A molecule that dissolves in a non-polar solvent Is made from isoprene units Is water soluble A MOLECULE THAT DISSOLVES IN A NON-POLAR SOLVENT Lipids are catabolized by the pathway. A. Glycolysis B. Β-oxidation C. Urea cycle D. Both A and C E. Both B and C B. B-OXIDATION FADH2 provides energy by donating electron and hydrogens to the . A. ETC B. CAC C. β-oxidation pathway D. glycolysis pathway E. All of the above A The direct production of ATP occurs as H+ ions flow through into the mitochondrial matrix. Complex I Complex II Complex III Complex IV ATP synthase ATP SYNTHASE The following processes result in either the “Production of ATP" or in the “Consumption of ATP”. Put each of the following into the appropriate category. 1. Fructose-6-phosphate forms Fructose-1,6-bisphosphate Consumption of ATP 2. Oxidative phosphorylation Production of ATP 3. Glucose forms two pyruvates Production of ATP 4. Pyruvate forms acetyl-CoA Production of ATP 5. NH4+ is made into urea Consumption of ATP In human cells, amino acids are degraded to ammonium NH4+ and carbon skeletons. How is the nitrogen then further processed and excreted from these cells? Nitrogen is processed separately from carbon and oxygen, in the urea cycle. The urea cycle is a four-step cyclic process that converts NH4+ to urea, which is then excreted from the body. Once the NH4+ is removed, it is acted upon in the mitochondria by an enzyme, carbamoyl phosphate synthetase 1, that synthesizes carbamoyl-phosphate. The carbamoyl phosphate enters the cytosol and continue through the three further steps of the urea cycle producing urea. The urea, containing two atoms of nitrogen, is then excreted. Describe at least three properties of carbon that permit it to be the basis of life. 1. Carbon can form sable covalent bonds with a variety of different elements. 2. Besides, carbon can form double and triple bonds with other carbon atoms and other elements (N and o). 3. Carbon can form long chains by forming numerous carbon-carbon bonds; we call these large molecules polymer. 4. Lastly, carbon can form cyclic structures, which are also called ring compounds. Which types of molecules are most likely to be present in membranes? Phosphoglycerides, sphingolipids, cholesterol, and proteins are all found in the membrane. These molecules are all loosely associated with each other as described by the fluid mosaic model of the cellular membrane. They form a membrane bilayer. A group of molecules forms a clathrate in water. What is a clathrate and why does it form? The hydrophobic effect helps scientists explain how biological molecules form and interact. For instance, when molecules with both a nonpolar and polar regions dissolve in water, the nonpolar regions pack together. The packing of the nonpolar regions minimizes the interaction with water and the polar region interact with water, which in total is called the hydrophobic effect. The driving force behind this effect is the spontaneous drive of water to bind to itself through hydrogen bonds. To maximize the hydrogen bonds, water orders itself around the hydrophobic portion of the nonpolar regions in a cage structure also called a clathrate. In so doing, water can form bonds with itself and also permit the nonpolar regions to be dissolved.