Bio 181 Exam 1

Which level of protein structure is shown in the picture below

• Primary

• Secondary

• Tertiary

• Quaternary

Which level of protein structure is shown in the picture below for the two proteins?

• primary

• secondary

• tertiary

• quaternary

Would the subsitution (due to a mutation) of alanine (hydrophobic amino acid) for serine (a polar and hydrophobic amino acid) have a large or small effect on the structure of a protein?

• Yes, likely a large effect. The substitution of two chemically very different amino acids could have a large effect on protein structure.

• No, likely little effect. Substituting just one amino acid (even a chemically different one) will not change the overall protein structure appreciably.

What type of chemical bond is important for stabilizing alpha-helix or Beta-sheets between backbone atoms of amino acids in close proximity to one another?

• Hydrogen bonds

• Van der Waals forces

• Covalent bonds

• Ionic bonds

If a protein is subject to changes in temperature, pH, or exposure to chemicals this may result in:

• Dimerization

• Denaturation

• Saturation

• Helical formation

The image below shows what type of chemical compound?

• Glycerol

• Fatty acid

• Triacylglycerol

• Nucleic acid

The image below shows what kind of compound?

• Lipid

• A sterol, specifically cholesterol

• A nucleic acid

• Both a and b

What kinds of structure will the following compound, a phospholipid, form in a watery environment?

• Membrane

• Micelle

• Liposome

• All of the above

With the complementarity of nucleic acids in mind (in DNA strands) answer the following question.

A particular stretch of DNA is sequenced and found to be 40% Guanine. What percentage will be Adenine?

• 40%

• 20%

• 10%

• 5%

Which of the following macromolecules is most likely to form into a double helix?

• Proteins

• Nucleic acid: DNA

• Nucleic acid: RNA

• Lipids