BCH 3025 Exam 1 Questions With Correct Answers

EXAM STUDY MATERIALS July 26, 2024 9:30 AM BCH 3025 Exam 1 Questions With Correct Answers In a bacterial cell, the DNA is in the: - answer✔✔nucleoid A major change occurring in the evolution of eukaryotes from prokaryotes was the development of: - answer✔✔the nucleus In eukaryotes, the nucleus is enclosed by a double membrane called the: - answer✔✔nuclear envelope The dimensions of living cells are limited, on the lower end by the minimum number of biomole cules necessary for function, and on the upper end by the rate of diffusion of solutes such as oxygen. Except for highly elongated cells, they usually have lengths and diameters in the range of: - answer✔✔0.3 m to 100 m Which group of single -celled micro -organisms has many members found growing in extreme environments? - answer✔✔archaea The bacterium E. coli requires simple organic molecules for growth and energy - it is therefore a: - answer✔✔chemoheterotroph Which one of the following has the cellular components in order of increasing size? - answer✔✔Amino acid < protein < ribosome < mitochondrion The three -dimensional structure of macromolecules is formed and maintained primarily through non-covalent interact ions. Which one of the following is not considered a non -covalent interaction? - answer✔✔carbon -carbon bonds Which one of the following is not among the four most abundant elements in living organisms? - answer✔✔Phosphorus The four covalent bonds in methan e (CH4) are arranged around carbon to give which one of the following geometries? - answer✔✔tetrahedral What functional groups are present on this molecule? (11) - answer✔✔hydroxyl and aldehyde The macromolecules that serve in the storage and transmission of genetic information are: - answer✔✔nucleic acids Stereoisomers that are non -superimposable mirror images of each other are known as - answer✔✔enantiomers. EXAM STUDY MATERIALS July 26, 2024 9:30 AM The enzyme fumarase catalyzes the reversible hydration of fumaric acid to l -malate, but it will not catalyze the hydration of maleic acid, the cis isomer of fumaric acid. This is an example of: - answer✔✔stereospecificity Humans maintain a nearly constant level of hemoglobin by continually synthesizing and degrading it. This is an example of a(n): - answer✔✔dynamic steady state If heat energy is absorbed by the system during a chemical reaction, the reaction is said to be: - answer✔✔endothermic If the free energy change G for a reaction is -46.11 kJ/mol, the reaction is: - answer✔✔exergonic The major ca rrier of chemical energy in all cells is: - answer✔✔adenosine triphosphate Enzymes are biological catalysts that enhance the rate of a reaction by: - answer✔✔decreasing the activation energy Energy requiring metabolic pathways that yield complex molecules from simpler precursors are: - answer✔✔anabolic Hereditary information (with the exception of some viruses) is preserved in: - answer✔✔deoxyribonucleic acid When a region of DNA must be repaired by removing and replacing some of the nucleotides, what ensur es that the new nucleotides are in the correct sequence? - answer✔✔The new nucleotides basepair accurately with those on the complementary strand The three -dimensional structure of a protein is determined primarily by: - answer✔✔the sequence of amino acids in the protein. According to Oparin's theory for the origin of life, the prebiotic atmosphere: - answer✔✔had an abundance of methane, ammonia, and water The chirality of an amino acid results from the fact that its carbon: - answer✔✔Is bonded to four different chemical groups Of the 20 standard amino acids, only _____ is not optically active. The reason is that its side chain _____. - answer✔✔Gylcine; is a hydrogen atom Two amino acids of the standard 20 contain sulfur atoms. They are: - answer✔✔Methionine and cysteine All of the amino acids that are found in proteins, except for proline, contain a(n): - answer✔✔Amino group Which of the following statements about aromatic amino acids is correct? - answer✔✔On a molar basis, tryptophan absorbs more ultraviole t light than tyrosine