Lecture 3 Learning Outcomes - BIOL2085 Cell Biology - Professor Maria Torres

Which of the following is NOT correct about amino acids? -they can form ionic bonds -they are composed of a central carbon surrounded by an amino group, a carboxyl group, a hydrogen atom and a variable side chain -they can form peptide bonds -they can have side chains that are polar, nonpolar, or with unique properties -they are joined together in a protein by glycosidic bonds

-they are joined together in a protein by glycosidic bonds

Saturated fats tend to be solid at room temperature because they can form more intermolecular bonds called -covalent bonds -hydrogen bonds -van der Waals forces -electrostatic attractions

-van der Waals forces

Considering that the pKa of an amino group of an amino acid if about 8 and of the carboxyl is 3, what would be the charge on this amino acid at pH 4? 0 -2 +1 -1

0

At neutral pH, the carboxyl group of an amino acid will probably be found as: -COOH -COOH- -COO- -COH

COO-

saturated fats have higher melting points because: -intermolecular interactions are weaker than between unsaturated fats -their functional groups have different polarity than unsaturated fats -they remain liquid at room temperature -their shape allows them to pack closer together

their shape allows them to pack closer together

Highly saturated fatty acids tend to be solid at room temperature: -true -false

true

Hydrogenation of fatty acids is a process by which: -double bonds are decreased to decrease the melting temperature -double bonds are increased to increase the melting temperature -double bonds are decreased to increase the melting temperature -double bonds are increased to decrease the melting temperature

-double bonds are decreased to increase the melting temperature