721. Which of the following conditions would cause the release of the lac repressor protein from the lac operator site on DNA?
A. Presence of glucose in the growth media
B. Presence of lactose in the growth media
C. Presence of IPTG (isopropyl thiogalactoside) in the growth media
D. Both (b) and (c)

722. Beta pleated sheets are examples of protein’s
A. primary structure
B. secondary structure
C. tertiary structure
D. quaternary structure

723. BRACl, an inherited form of breast cancer, regulates cell division by
A. binding to a DNA sequence
B. complexing with cyclins
C. binding to the cell outer membrane
D. binding to the protein RAD 51 which repairs DNA damage

724. Metastasis involves
A. ability of cells to dissolve cellular matrix
B. metalloprotein levels
C. decreased levels of proteins that regulate metalloproteins
D. all of the above

725. Signal sequences are part of a protein that
A. signal folding of the protein
B. signal the protein synthesis on the ribosomes is ended
C. transport proteins to other sites within the cell
D. refold proteins in prion-associated diseases

726. Individuals with PKU disease are mentally retarded unless
A. phenylalanine in the diet is restricted
B. tyrosine in the diet is restricted
C. homogentisic acid in the diet is restricted
D. none of the above

727. Marfan’s syndrome is thought to be a mutation affecting
A. hemoglobin synthesis
B. collagen synthesis
C. metabolism of homogentisic acid
D. insufficient thyroid production

728. Cyclins are proteins that
A. regulate ability of cells to invade tissue
B. regulate passage from one stage of cell division to another
C. regulate apoptosis of damaged cells
D. none of the above

729. Over 50% of common cancers are associated with damage to a protein, p53. This protein
A. is a cyclin
B. is a tumor supressor
C. is an oncogene
D. regulates apoptosis

730. Protein folding is
A. automatic, mediated by the protein itself
B. mediated by other proteins called chaperones
C. mediated by the ribosomes
D. none of the above