1011. The Ramachandran Plot illustrates the fact that
A. the peptide bond is planar
B. the F & Y angles can assume any value in a peptide
C. the F & Y angles can assume only a single value in a protein
D. the F & Y angles can assume approximately three different values

1012. What condition is caused by iodine deficiency during pregnancy and is characterized by stunted growth, deafness, and mental retardation?
A. Cretinism
B. Keshan disease
C. Multiple sclerosis
D. Crohn’s disease

1013. In the intestine, the dietary fats are hydrolysed by
A. triacylglycerol lipase
B. adenylate cyclase
C. pancreatic lipase
D. protein kinase

1014. A solution with pH = 5 is __________ than a solution with pH = 7.
A. 2 times more basic
B. 10 times more basic
C. 10 times more acidic
D. 100 times more acidic

1015. The lone pair electrons on oxygen in a H20 molecule
A. carry a partial positive charge
B. are not important for the properties of water
C. carry a partial negative charge
D. form covalent bonds in ice

1016. Which of the following statements about water is correct?
A. It is critical for many of the chemical processes found in living systems
B. Polar substances that can form hydrogen bonds will dissolve in it
C. Nonpolar substances like oils are not soluble in it
D. All of the above

1017. The strength of an acid depends on
A. number of neutrons gain
B. electronegativity
C. number of double bonds
D. number of protons released

1018. Which of the following statements about covalently bonded molecules is false?
A. Electrons are shared between the atoms that make up the molecule
B. Noncovalent bonds may also be present, especially if the molecule is large
C. Such molecules often result from the interaction of ionized atoms
D. The chemical bonds that hold the molecule together are relatively strong

1019. Which of the following character does not apply to water?
A. The water molecule is asymmetric
B. The water molecule readily forms hydrophobic interactions
C. The covalent bonds in water are highly polarized
D. All three atoms in the water molecule readily form hydrogen bonds

1020. The dissociation constant of H2O at 25° C is
A. 10-14 M
B. 1014 M
C. 10-7 M
D. 107 M