1-12 Ap Biology Exam Questions And Answers New Update 2024/2025 Top Ranked A+ Best Exam

During protein metabolism, the amino acid phenylalanine is changed to the amino acid tyrosine via the enzyme phenylalanine hydroxylase (PAH). Tyrosine is then used to make L-Dopa via a second enzyme. If Beadle and Tatum's one gene-one enzyme model holds true for this metabolic pathway, what is the result of a PAH mutation that alters its functionality? {Ans: an accumulation of phenylalanine and no production of tyrosine and L-Dopa}In some species of bacteria that are resistent to the antibiotic tetracycline, the antibiotic molecule attaches to a repressor protein. This prevents binding of the repressor to the bacterial DNA and allows a set of genes to be transcribed. The transcription of these genes is under the control of a(n) __________. {Ans: operon}The "normal" function of restriction enzymes is to _____. {Ans: destroy foreign DNA}The lipids that form the main structural component of cell membranes are _____. {Ans: phospholipids}Enzyme molecules require a specific shape to perform their catalytic function. Which of the following might alter the protein shape? {Ans: changing the concentration of salt in the environment}Sodium chloride (NaCl) dissolves in water because water molecules _____. {Ans: are polar}