Cell Physiology Test 1 Q1 Practice Questions

Proteins must have more than one _______ to have a quaternary structure. A. polypeptide chain B. transmembrane segment C. β sheet D. 𝛂 Helix

A .polypeptide chain

Introducing a double bond into a fatty acid has the effect of putting a(n) _______ into the conformation of the molecule. A. kink B. amino acid bulge C. reinforcing rod D. All of the above

A. kink

Cell membranes are composed principally of A. Lipids B. Nucleic acids C. Carbohydrates D. Water E. Proteins

A. lipids

In the primary structure of a protein, amino acids are joined together by _______ bonds. A. peptide B. hydrophobic C. phosphodiester D. glycosidic E. ionic

A. peptide bonds

Which part of amino acid makes it unique from all others? A. Side Chain B. Sugar C. Phosphate group D. None of the above

A. side chain

Cholesterol is an amphipathic molecule. A. True B. False

A. true

In the fluid mosaic model of biological membrane structure, transmembrane proteins are A. almost completely surrounded by membrane lipid. B. embedded nearly randomly in the lipid bilayer. C. segregated into large protein clusters or rafts. D. weakly held in place on the surface of the lipid bilayer.

B. embedded nearly randomly in the lipid bilayer.

Mutation in the DNA will ONLY affect primary structure of the protein but never tertiary A. true B. false

B. false

Each membrane phospholipid contains 3 fatty acid chains. A. True B. False

B. false 2 fatty acids chains

The currently accepted model of membrane structure is called the _________ model A. Lipid bilayer B. Fluid mosaic C. Lipid raft D. Unit membrane E. Lipoprotein

B. fluid mosaic

Water is an ideal solvent in cells because it A. has low heat of vaporization. B. is a polar molecule that can form hydrogen bonds with itself and with other polar molecules. C. dissolves nonpolar molecules. D. contracts when it freezes. E. All of the above

B. is a polar molecule that can form hydrogen bonds with itself and with other polar molecules

An amphipathic molecule is A. Water-insoluble B. Part water-soluble and part water-insoluble C. Water-soluble D. Hydrophilic E. Hydrophobic

B. part water-soluble and part water-insoluble

The α (alpha) helix is an example of which level of protein structure? A. Tertiary B. Secondary C. Primary D. Quaternary

B. secondary

Proteins can be described as which of the following? A. Are made from only 4 types of monomers B. They carry out the program encoded by genes C. Are synthesized in the nucleus D. They are the primary form of energy for a cell.

B. they carry out the program encoded by genes

The linear order of amino acids in a protein determines its A. Location in the cell B. Size C. Structure D. Transcription

C. structure

In most proteins, α helices and β sheets fold into globular domains with _______ on the inside. A. Hydrophobic amino acids B. Uncharged amino acids C. Hydrophobic side chains D. All of the above

D. All of the above

Lipids play a major role in cells as A. a form of energy storage. B. components of cell membranes. C. part of the cell signaling function. D. All of the above E. None of the above

D. All of the above

Which of the following are involved in forming the tertiary structure of proteins? A. H Bonds B. Hydrophobic interactions C. Ionic bonds D. All of the above E. None of the above

D. All of the above

A disulfide bond is formed between _______ residues. A. tyrosine B. glycine C. methionine D. cysteine

D. cysteine

The interaction of the α and the β subunits to form the hemoglobin molecule is an example of __________ structure. A. Secondary B. Primary C. Tertiary D. Quaternary

D. quaternary

Phospholipids in a membrane commonly A. move laterally in the plane of the bilayer B. rotate within the bilayer C. move from one bilayer to the other. D. both a and b E. All of the above

E. All of the above

The most common molecules in cellular membranes are the A. triglycerides. B. glycolipids. C. cholesterol molecules. D. proteins. E. phospholipids.

E. phospholipids.