Principles Test Two

Sucrose is formed when glucose is joined to fructose by a(n) _________.

• peptide linkage

• glycosidic linkage

• ionic bond

• ester linkage

Plant cell walls consist mainly of ___________.

• Chlorophyll

• Chitin

• Peptidoglycan

• Cellulose

The characteristic that all lipids have in common is ___________.

• they are all made of fatty acids and glycerol

• they are all acidic when mixed with water

• they do not have a high energy content

• they all contain nitrogen

• none of them dissolve in water

In peptidoglycan, the folding is called _________, and the coils or folds are held in place by __________.

• tertiary structure, hydrogen bonds

• tertiary structure, covalent bonds

• secondary structure, peptide bonds

• secondary structure, hydrogen bonds

A hydrophobic amino acid R group would be found where in a properly folded protein?

• On the outside of the folded chain, exposed to water molecules

• only at one end of a protein chain

• Forming hydrogen bonds with other R groups

• On the inside of the folded chain, away from water molecules

Which of the following clues would tell you if a cell is prokaryotic or eukaryotic?

• the presence of absence of ribosomes

• whether or not the cell is generally partitioned by internal membranes

• whether or not the cell is generally partitioned by the internal membranes

• whether or not the cell contains DNA

Which of the following statements about a typical plasma membrane is corect?

• Phospholipids are the primary component that determines which solutes can cross the plasma membrane.

• The two sides of the plasma membrane have different lipid and protein composition.

• The plasma membrane is a covalently linked network of phospholipids and proteins that controls the movement of solutes into and out of a cell

• The hydrophillic interior of the membrane is composed primarily of the fatty acid tails of the phospholipids

Which of the following best describes the structure of a biological membrane?

• two layers of phospholipids, with proteins embedded between the two layers

• a fluid structure in which phospholipids and proteins move freely between sides of the membrane

• two layers of phospholipids, with proteins either crossing the layers or on the surface of the layers

• a mixture of covalently linked phospholipids and proteins that determines which solutes can cross the membrane and which cannot

Which of the following is least likely to be important in holding the components of a biological membrane together?

• polar interactions among the phospholipid head groups on the same surface of the membrane

• hydrophobic interactions among the fatty acid tails of phospholipids on the same side of the membrane

• hydrophobic interactions between the phospholipid tails and the surface of integral membrane proteins buried in the membrane

• covalent interactions between the phospholipid and protein components of the membrane

Which of the following statements best describes a characteristic feature of integral membrane proteins?

• They are hydrophilic.

• They are hydrophobic.

• They are localized to the interior surface of the membrane.

• They are amphipathic, with at least one hydrophobic region.