CH. 2 Flashcards
The polymerization of different types of macromolecules is similar in many respects. Which of the following principles below is least likely to be common to all methods of polymerization of macromolecules?
polymerization is passive, requiring little ATP
An enzyme synthesized in the lab is found to have little activity when compared to the enzyme extracted from cell culture. Both enzymes were examined and have identical amino acid composition. What is the best explanation for the lack of activity of the synthesized enzyme?
the synthesized enzyme was not folded correctly because molecular chaperones were not present
the nucleotide triphosphate molecules in DNA are linked in the 5’?3’ by a(n) ______ bridge
phosphodiester
Carbon can form the _______ covalent bond.
single, double, triple
While synthesizing a new blue pigment, a chemist notices that the new compound congregates between an aqueous (water) environment and a hydrophobic environment. When added to a mixture of oil and water, the pigment creates a blue ring around the droplets of oil. Which of the following statements best describes this new pigment? The pigment is
is amphipathic, having polar and nonpolar regions
The term amphipathic refers to those molecules that are
charged at one end and nonpolar at the other
polymers are synthesized by condensation reactions and broken down into their constituent monomers by hydrolysis reactions
true
why do polar substances such as NaCl dissolve so readily in water?
- spheres of hydrogen from between the water and the ions
- the charged ends of the water molecules are able to surround the oppositely charged salt ions
Which of the following statements about the polymerization of macromolecules is false?
water is added to join the monomers of the macromolecules
As a protein is being synthesized, the correct folding of the protein is aided by the movement of nonpolar amino acids toward the inner areas of the protein. This phenomenon can be explained by the exclusion of hydrophobic groups from the aqueous surface, called the hydrophobic effect.
True
the amino acid referred to as “helix breaker” (because it lacks the hydrogen atom needed for hydrogen bonding) is
proline
which of the following is not a characteristic of DNA?
has ribose
in the lab , you choose to design a simple experiment to distinguish between hydrophilic and hydrophobic substances. You start by adding equal amounts of vinegar and oil to a container. After shaking , the vinegar and oil levels separate, based upon polarity and density. To this you add glucose and sodium citrate and shake again. Where do you expect to find the glucose and sodium citrate in greatest quantities?
both will concentrate in the vinegar layer
macromolecules are synthesized by a series of steps. Monomers are systematically added to the growing polymer. Therefore people who are trying to lose weight are asked to drink plenty of water since water is released in the synthesis of polymers like fats (condensation reaction), water will be needed for the breakdown of fat molecules (hydrolysis)
true
the chemical nature of each amino acid is determined by which of the following groups?
R
Hydrogen bonding is most important in stabilizing the _____ structure of many proteins
secondary
Based on the following amino acid sequence, which region(s) in/are hydrophobic? 1[K-K-N-Q]-2[A-G-G-V]-3[Y-C-S-R]-4[H-E-C-Y]
region 2
A phosphate group, a sugar (ribose or deoxyribose), and a base are the major parts of a nucleotide, whereas a sugar and a base are the major parts of a nucleoside
true
detergents are best able to dissolve oil from fabric or dishes during washing because
charged end is associated with a sphere of hydrogen, while non polar end interacts with oil droplets
disulfide bonds are often found to stabilize which of the following levels of protein structure?
tertiary
the term amphipathic describes the characteristic of some molecules that have ____
both a polar and non polar region
which one of the following biological polymer is mismatched with its monomer?
cellulose- amino acid
monomers are removed from polymers by ____ reactions
hydrolysis
the primary structure of a protein
- is important for determining the secondary and tertiary structure of a protein
- is simply the order of amino acids from one end of the protein to another
- is important both genetically and structurally
- is the linear sequence of amino acids that are linked by peptide bonds
Fibrous proteins have an extensive _______ Structure allowing them to be highly ordered and repetitive
secondary
which of the following is notA possible non-covalent Interaction?
Polar covalent bonding
The hierarchical Nature of a cellular structure is accurately illustrated in which of the following list of substances (from smallest to largest)?
Nucleotides, DNA, chromosomes, nucleus, cell
