Exam 3: Lifes Components: Biological Molecules

Both men and women make testosterone.

In many cases,carbohydrates have the following ratio of elements:

Amino acids are monomers used to build:

Amino acids contain both amino and carboxyl functional groups.

Alpha helices and beta pleated sheets are examples of:

Saturated fats are usually found in:

Proteins that are composed of more than one polypeptide chain are said to have ________ structure.

Water is an organic molecule.

Glycogen is a polysaccharide used for energy storage by:

Glycogen is the carbohydrate found in plant cell walls.

Before DNA was established as the genetic material,proteins were considered the most likely molecules to serve this role.In part this belief was based on the fact that there are 20 building blocks (20 different kinds of amino acids)for proteins versus 4 building blocks (4 different nucleotides)for DNA.If proteins stored a code,there would be a far greater number of code words possible for a protein of a given number of amino acids than for a DNA molecule of the same number of nucleotides.For example,there are 16 different sequences (4²)possible for a DNA two nucleotides long and 400 (20²)different sequences possible for a protein two amino acids long.For a sequence three nucleotides or three amino acids in length,the number of distinct DNA sequences is ________,and the number of distinct protein sequences is ________.

A functional group added to a hydrocarbon usually makes the hydrocarbon:

Polypeptides differ in their ________ and ________ of amino acids.

Which of the following is the indigestible (at least for humans)glucose polysaccharide that is found in plants?

Hydroxyl groups are functional groups found on amino acids.

What do polysaccharides,such as cellulose; nucleic acids,such as DNA; and proteins,such as keratin,have in common?

Wax is a lipid.

You have a genetic defect that prevents your cells from making the amino acid tryptophan from indole and serine.Your cells might be lacking the proper information in their ________,which would direct the synthesis of the ________ that catalyzes tryptophan synthesis.

In some vintage science fiction movies,space travelers find themselves on a planet orbiting a distant star in which there are curious forms of life based on silicon instead of carbon.Although the story clearly is sci-fi,there is an aura of plausibility in the choice of silicon,an atom with 14 protons,in place of carbon as this alien life-form's central atom.The reason is that silicon: