Exam 2: The Chemical Basis of Life

Which of the following is not a macromolecule formed by polymerization?

What enzyme is responsible for the destruction of a type of free radical formed when molecular oxygen picks up an extra electron?

Since replication is a property characteristic of nucleic acids,how might a prion,which lacks nucleic acids,"replicate" itself?

Why might an organism that had functional SOD but mutant catalase and/or glutathione peroxidase be at a disadvantage?

Under which circumstances would electrons be most likely to be shared equally?

Many so-called temperature-sensitive mutations have been discovered in a wide variety of organisms.These are proteins that are non-functional at higher temperatures,while,at lower temperatures (often just a few degrees lower),they function normally.For example,the coloration patterns in Siamese Cats arise from a temperature-sensitive mutation.An enzyme required for the synthesis of dark pigment is unable to function in areas close to the body where normal physiological temperatures prevail.However,at the tips of the ears,paws,the tip of the tail and other extremities where the temperature is slightly lower,the enzyme works correctly and dark pigment is produced.What is happening at the molecular level that explains this?

What human disease was found to be similar to kuru in the brain abnormalities it caused? What disease in sheep contributes its name to the abnormal prion molecule,PrPSC? What have been the causes of outbreaks of acquired CJD?

Which amino acid is most likely to be found in the core of a protein?

The $\beta$ -pleated sheet is characterized by orientation of ______ the molecular axis.

What kind of noncovalent interaction is typified by interactions between two molecules that are so close together that they can experience weak attractive forces bonding them together?

What is a randomized,double-blind,placebo-controlled study?

In a living organism,where are ionic bonds most likely to be found?

Which of the groups below is capable of only hydrophobic interactions?

What are some possible explanations for the branched structure of glycogen?

What are some common antioxidants found in the body?

The most electronegative atoms typically present in biological molecules are ____ and ____.

Which of the following groups is capable of only hydrophilic interactions?

An enzyme is placed in a solution containing urea.Assuming that this protein contains no disulfide linkages,is it reasonable to suspect that it will be totally denatured by the treatment? How could you know that the enzyme has,in fact,been denatured? Why does the urea denature the tertiary structure of the enzyme?

What is some specific evidence that demonstrates the importance of superoxide dismutase in getting rid of superoxide free radicals?

Given what you have learned about SOD,what do you hypothesize would happen to fruit flies that have been genetically engineered to produce large amounts of SOD? Why might houseflies that are kept caged and unable to fly live longer than those allowed to fly?