Exam 2: Chemistry Comes Alive

Which of the following is the major positive ion outside cells?

Which type of proteins can function as chemical messengers or as receptors in the plasma membrane?

When a set of electrodes connected to a light bulb is placed in a solution of dextrose and a current is applied, the light bulb does not light up. When the same unit is placed in HCl, it does. Why?

Triglycerides are a poor source of stored energy.

Salts are always__________ .

Why is it possible for us to drink a solution that contains a mixture of equal concentration of a strong acid and a strong base, either of which, separately, would be very caustic?

Lithium has an atomic number of 3. How many electrons are there in the outermost (valence) shell?

The numbers listed represent the number of electrons in the first, second, and third energy levels, respectively. On this basis, which of the following is an unstable or reactive atom?

Glucose is an example of a monosaccharide.

How can DNA be used to "fingerprint" a suspect in a crime?

Salivary amylase is an enzyme produced by the salivary glands that breaks down carbohydrates. What will happen to this enzyme as it follows the food into the stomach where the pH drops to 2.5?

Buffers resist abrupt and large changes in the pH of body fluids by releasing or binding ions.

Isotopes differ from each other only in the number of electrons the atom contains.

ATP ·ADP + Pi is an example of a(n)__________ reaction.

A chemical bond is an energy relationship between outer electrons and neighboring atoms.

What happens in redox reactions?

Which of the following elements is necessary for proper conduction of nerve impulses?

What structural level is represented by the sequence of amino acids in a polypeptide chain?

What happens when globular proteins are denatured?

It is the difference in the R group that makes each amino acid chemically unique.