TAMU 213 BIOL Dr. Quin (1) Questions and Answers correct

TAMU 213 BIOL Dr. Quin (1) Questions and Answers correct 1) ΔG for spontaneous reactions is a) positive b) negative c) either positive or negative b) negative 2) For a chemical reaction, ΔG depends a) only on the energy stored in in each molecules in the reaction mixture b) only on the concentrations of the molecules in the reaction mixture c) not only on the energy stored in in each molecules, but also on the concentrations of the molecules in the reaction mixture d) on neither of the above factors. c) not only on the energy stored in in each molecules, but also on the concentrations of the molecules in the reaction mixture 3) Which of the following statement is correct: a) Phospholipids, fatty acids, and triacylglycerol are amphipathic b) Phospholipids and triacylglycerol are amphipathic c) Phospholipids and fatty acids are amphipathic d) Phospholipids, and amino acids are amphipathic c) Phospholipids and fatty acids are amphipathic 4) The solubility of a protein depend on a) the side group of the amino acids in the protein b) the backbone of the protein c) other proteins d) none of the above. a) the side group of the amino acids in the protein 5) The side chain of nucleic acids contains a) pentose sugar b) phosphate group c) nitrogenouse base d) pentose sugar and phosphate group c) nitrogenouse base 6) Which following statement is wrong? a. Cells vary enormously in appearance and function. b. Living cells all have similar basic chemistry. c. All present-day cells have apparently evolved from the same ancestor. d. All cells have nucleus. d. All cells have nucleus. 7) All cells have at least a a. mitochondria b. membrane c. nucleus d. endoplastic reticulum b. membrane 8) The most convincing evidence supporting that chloroplast evolved from engulfed bacteria are: a) these organelles contain their own DNA and they reproduce by dividing in two b) they generate usable energy from food to power the cell c) they have distinctive structure d) these organelles contain their own DNA and they have distinctive structure a) these organelles contain their own DNA and they reproduce by dividing in two 9) Which of the following expressions accurately describes the calculation of pH? a) pH = -log10[H+] b) pH = log10[H+] c) pH = -log2[H+] d) pH = -log10[OH-] a) pH = -log10[H+] 10) Which following statement is correct? a. Enzymes are all proteins. b. Enzymes allow ΔG positive reaction to occur. c. Enzymes promote reaction by reducing energy of activation d. both a) and c) are right c. Enzymes promote reaction by reducing energy of activation 11) Covalent and noncovalent chemical bonds have different lengths and strengths. Ionic bond is considered as a weak bond (a) in vacuum (b) both in vacuum and in water (c) in water (d) none of the above (c) in water 12) The pH of one acid solution is 1 and the pH of apple juice is 3. How much more acidic is the acid solution than orange juice? a) 2-fold b) 10-fold c) 5-fold d) 100-fold d) 100-fold 13) Here are two biochemical reactions. ΔG for reaction 1 is -352 kcal/mol. ΔG for reaction 2 is -20 kcal/mol. Which reaction has a faster rate? a. reaction 1 b. reaction 2 c. they have the same rate d. cannot tell d. cannot tell 14) What unit of length would you generally use to measure a typical human cell? (a) centimeters (b) nanometers (c) millimeters (d) micrometers (d) micrometers 15) If [S] is much smaller than KM, the active site of the enzymes is mostly a. occupied b. unoccupied b. unoccupied 16) If [S] is much bigger than KM, the reaction rate is limited by the a) enzymes concentration b) substrate concentration. a) enzymes concentration 17) The chemical band linking glucose into polysaccharide is called a) glycosidic bond b) phosphodiester band c) ester bond d) amide band a) glycosidic bond 18) The polysaccharide shown in the picture is a. starch b. cellulose c. chitin d. glucosamine a. starch 19) ΔG for this reaction is a) positive b) negative c) zero d) none of the above a) positive 20) Which pair of values best fills in the blanks in this statement: On average, eukaryotic cells are __________ times longer and have _________ times more volume than prokaryotic cells. (a) 5, 100 (b) 10, 200 (c) 10, 100 (d) 10, 1000 (d) 10, 1000 Many of the mechanisms that cells use for maintenance and reproduction were first studied at the molecular level in bacteria. Which bacterial species had a central role in advancing the field of molecular biology? (a) E. coli (b) D. melanogaster (c) S. pombe (d) C. elegans (a) E. coli 22) The amino acids glutamine and glutamic acid are shown in Figure below. They differ only in the structure of their side chains (circled). At pH 7, glutamic acid can participate in molecular interactions that are not possible for glutamine. What types of interactions are these? (a) ionic bonds (b) hydrogen bonds (c) van der Waals interactions (d) covalent bonds (a) ionic bonds DNA and RNA are different types of nucleic acid polymer. Which of the following is true of DNA but not true of RNA? (a) It contains uracil. (b) It contains thymine. (c) It is single-stranded. (d) It has 5′-to-3′ directionality. (b) It contains thymine. ΔG° indicates the change in the standard free energy as a reactant is converted to product. Given what you know about these values, which reaction below is the most favorable? (a) ADP + Pi ATP ΔG° = +7.3 kcal/mole (b) glucose 1-phosphate glucose 6-phosphate ΔG° = -1.7 kcal/mole (c) glucose + fructose sucrose ΔG° = +5.5 kcal/mole (d) glucose CO2 + H2O ΔG° = -686 kcal/mole (d) glucose CO2 + H2O ΔG° = -686 kcal/mole Which of the following statements is true? (a) Peptide bonds are the only covalent bonds that can link together two amino acids in proteins. (b) The polypeptide backbone is free to rotate about each peptide bond. (c) Nonpolar amino acids tend to be found in the interior of proteins. (d) The sequence of the atoms in the polypeptide backbone varies between different proteins. (c) Nonpolar amino acids tend to be found in the interior of proteins.