Creighton University Bio 206 Final Study Guide Rated A+

A cell will pass the M-Phase checkpoints if... {Ans: 1. Chromosomes have attached to the spindle apparatus 2. Chromosomes have properly segregated and MPF is absent}leading strand synthesis {Ans: DNA polymerase I and helicase are moving in the same direction. DNA polymerase reads the strands in the 3'-5' direction}sister chromatids {Ans: chromatid copies that remain attached at their centromere}What happens during S phase? {Ans: chromosomes are replicated prior to mitosis}Back in chapter 4 we discussed how nucleotides are assembled into nucleic acids through the formation of phosphodiester bonds. Making a phosphodiester bond is an endergonic process. The new nucleotide that is being added to the nucleic acid chain is in its tri-phosphate form initially, and the energy from cleaving off two of the phosphate groups from that nucleotide is used to make the new phosphodiester bond. A single enzyme, DNA polymerase, simultaneously catalyzes both the hydrolysis of the phosphate groups and the formation of the phosphodiester bond. This is an example of: a.energetic coupling b.acidic hydrolysis c.oxidation followed by reductiond. d. substrate level phosphorylation {Ans: a}What does potential energy do in the ETC? {Ans: decreases at each step}