5. Which is NOT a microtubule-organizing center (MTOC)?
(A) centrosome
(B) basal body of cilia
(C) mitotic spindle pole
(D) kinetochore
(E) all of the above

1. If the amount of enzyme in a reaction with an initial △G of -5 kcal/mole was doubled, what would the △G be? (A) -2.5 kcal/mole (B) -5 kcal/mole (C) -10 kcal/mole (D) +5 kcal/mole (E) +10 kcal/mole

2. Which is the most common route through which a protein is secreted from a eukaryotic cell? (A) plasmidplasma membranenuclear envelopesmooth endoplasmic reticulum (ER) (B) Golgi apparatuslysosomevesiclesplasma membrane (C) nuclear envelopevesiclesGolgi apparatusplasma membrane (D) rough endoplasmic reticulum Golgi apparatusvesicles plasma membrane (E) rough endoplasmic reticulumlysosomesvesiclescell membrane

3. Movement of integral membrane proteins between the apical and basolateral domains of an epithelial cell membrane is restricted by the presence of (A) lipid rafts. (B) basal lamina. (C) desmosomes. (D) tight junctions. (E) gap juncitions.

4. Which of the following statements about feedback inhibition in metabolic pathways is most correct? (A) The product of the pathway inhibits its own production by competitively binding to reactants in the metabolic pathway. (B) The product of the pathway inhibits its own production by noncompetitively binding to reactants in the metabolic pathway. (C) The product of the pathway inhibits its own production by competitively inhibiting the binding of a substrate to the active site of an enzyme within the metabolic pathway. (D) The product of the pathway inhibits its own production by noncompetitively inhibiting the binding of a substrate to the active site of an enzyme within the metabolic pathway. (E) All of the above

6. An mRNA sequence is 5’-AUG-GGC-ACU-CAU-ACU-UAA-3’, where AUG is the start codon and UAA is the stop codon. How many distinct aminoacyl-tRNA synthetases are required to translate the mRNA sequence? (A) 2 (B) 3 (C) 4 (D) 5 (E) 6

7. Self-splicing of group II introns is similar to nuclear pre-mRNA splicing because (A) both need snRNPs. (B) both need guanosine. (C) both need ATP. (D) both form lariat structure. (E) both form spliceosome.

8. Assuming a fat molecule can be oxidized into 2 glycerol molecules, which are then converted to glyceraldehyde-3-phosphate in intermediate glycolysis, how many ATP can be produced from a fat molecule? (A) 4 (B) 8 (C) 24 (D) 36 (E) 48

9. Which of the following proteins is NOT a component of focal adhesions? (A) cadherins (B) integrins (C) actin filaments (D) linker protein (E) fibronectin/collagen

10. Why is there a need to produce Okazaki fragments on the lagging strand, but NOT on the leading strand of DNA? (A) It is substantially more efficient to make several shorter strands rather than one longer strand of DNA. (B) The two parental strands of DNA are antiparallel and DNA polymerase makes DNA in the 5’ to 3’ direction only. (C) There lacks enough DNA ligase for bonding Okazaki fragments together if they were produced from both parental strands. (D) By having one leading strand and one lagging strand the cell can limit the amount of DNA polymerase used for chromosomal replication. (E) It is faster to make several smaller fragments than one larger fragment.

11. When observing the skeleton of a snake, you see the remains of hip and hind leg bones associated with four legged animals. These bones are called (A) convergent traits. (B) vestigial structures. (C) homologous structures. (D) analogous structures. (E) both homologous and analogous structures.