Biochemical Engineering Final Exam Questions With Verified Answers.

Biochemical Engineering Final Exam Questions With Verified Answers. Hydrophobic materials interact favorably with water - answerFalse Neutrons significantly count to atomic mass. - answerTrue Example of polar molecule is H2O - answerTrue Atomic number changes with covalent bond formation. - answerFalse Explain the difference between prokaryotes and eukaryotes? - answerProkaryotes means very simple and primitive microorganisms. They have no organelles other than ribosomes and are single celled. On the other hand, multicellular eukaryotes have a nucleus and other subcellular organelles surrounded by a well-defined membrane. Prokaryotes include bacteria and blue-green algae, while Eukaryotes include fungi, algae, protozoa, plant cells, insect cells, and animal cells. Explain the structure of carbohydrates and proteins. Explain in terms of bonding between its atoms. - answerCarbohydrates are giant macromolecules/biomolecules. They are the polymers of monomers called monosaccharides, connected together by glycosidic bond. Their molecular structure is [C(H2O)]x; where x>3. Each carbon atom has a hydroxyl group, except for the terminal carbon that with an aldehyde group. All the carbon atoms and their functional groups are covalently bonded. However, hydrogen bonds are also formed due to the strong electronegative oxygen atom. Carbohydrates of carbon atoms more than 5 have a tendency to undergo a cyclization reaction. Polysaccharides breaks down into its monomers via hydrolysis. Sugar monomers are generally water soluble crystalline solids. Carbohydrates exhibits stereoisomerism. Proteins are polymer made up of monomers called amino acids. There are 20 different types of amino acids, also known as α-amino acids, consist of an amine group, a carboxylic acid group, and a side group (R): all connected to the alpha-carbon atom. Amino acids are also amphiphilic in nature because they can make internal salt due to negatively charged carboxyl group and positively charged amine group. Amino acids have a side group known as amino acid residue. Different amino acids connect together via a peptide or dipeptide bond to make polymer chains. The structure of proteins has primary, secondary, tertiary, and quaternary structures, depending on the bonding interactions. Element X has an electronic configuration of 2,8,7. Its valence is: - answer1 All of the following are considered true about bacteria, except: - answerTrue and well defined nucleus Under normal or physiological conditions, which group is negatively charged: - answerCarboxyl group Which one of the following is true about lipids: - answerHydrophilic head and hydrophobic tail The concept of "induced fit" refers to the fact that: - answersubstrate binding may induce a conformational change in the enzyme, which then brings catalytic groups into proper orientation. In the α-helix the hydrogen bonds: - answerare roughly parallel to the axis of the helix The most common secondary structure of protein is - answerα-helix Tertiary structure is maintained by - answerpeptide bond, hydrogen bond, di-sulphide bond, All of the above A dipeptide has - answer2 amino acids and 1 peptide bond In enzyme controlled reaction, an increase in temperature will usually: - answerSpeed up a reaction (within limits) Enzymes are potent catalysts because they: - answerLower the activation energy for the reaction they catalyze The role of an enzyme catalyzed reaction is to: - answerIncrease the rate at which substrate is converted into product A mutation has changed an amino acid residue of a protein. Which statement best describes its location in a hydrophilic exterior. - answerInside the core of the protein since it is hydrophobic in nature. When a substrate binds to an enzyme, which of the following is true: - answerThere is an optimum pH for each specific enzyme Hydrogen bonding between carbonyl oxygen atoms and nitrogen atoms of amide groups causes a polypeptide to coil. - answerSECONDARY A protein contains four tertiary subunits. - answerQUATERNARY The amino acid sequence of a protein. - answerPRIMARY The overall shape of a protein is globular. - answerTERTIARY Explain why during protein denaturation, the secondary and tertiary structure disrupts? Explain in terms of bonding and the strength of bonds involved during protein formation and folding. - answerSecondary and tertiary structures are primarily due to the secondary bonding interactions such as H bonding, van der Waals interactions, and hydrophilic/hydrophobic interactions. These bonds are weaker than primary bond (proteins primary structure is due to