Ch2- Chemical Review and Macromolecules

an acid

A molecule that is capable of releasing or donating a hydrogen ion is termed _______.

lower pH

A release of hydrogen ions to a solution would most likely ____________.

ribonuclease A

Not all proteins are able to renature. When exposed to heat or some other denaturing treatment , some proteins are irreversibly denatured, while others can renature when the denaturant is removed. What is an example of a protein demonstrated to refold correctly?

domains

Proteins are often composed of two or more distinct modules that fold up independently of one another. They often represent parts of a protein that function in a semi-independent manner. These modules are called ______.

monomers

The low-molecular-weight building blocks of polymers are called _______.

full outer electron shells

The most stable atoms, and thus those that are typically nonreactive, are the atoms that have _______.

H bonds perpendicular

The β-pleated sheet is characterized by the orientation of ______ to the molecular axis.

when atoms of the same element are sharing them

Under which circumstances would electrons be most likely to be shared equally?

α(1—>6) glycosidic linkages

What bond is responsible for the branch points in glycogen and amylopectin?

van der Waals forces

What kind of noncovalent interaction is typified by interactions between two molecules that are so close together that they can experience weak attractive forces bonding them together?

quaternary structure

What level of structure in proteins is held together by R group interactions between different polypeptides?

α-helix

What type of protein secondary structure is characterized as being highly extensible because of its coiled structure?

the core of a water-soluble protein

Where are hydrophobic interactions most likely to occur?

polar covalent bond

Which bond results from an unequal sharing of electrons?

hydrogen bonds

Which interaction is most important in enhancing the solubility of macromolecules in water?

oxygen and nitrogen

Which of the following elements are commonly found in biological molecules and strongly electronegative?

lipids

Which of the following is NOT a macromolecule formed by polymerization?

adenine + ribose + phosphate

Which of the following is a nucleotide?

β(1—>4) glycosidic linkages

Which polysaccharide bond cannot be broken by mammalian enzymes that normally digest polysaccharides?

1

Why are free ionic bonds of little relevance and relatively unlikely to form in living organisms? 1) Cells are composed mostly of water, which interferes with ionic bonds between free ions. 2) Cells are largely hydrophobic and exclude ions. 3) Cells incorporate ions into larger molecules and prevent the formation of ionic bonds.

they have large numbers of hydroxyl groups

Why do sugars tend to be highly water soluble?

quaternary tertiary

You treat a partially purified preparation of protein with a reagent that breaks bonds between sulfur atoms. Which level(s) of protein structure are most likely to be affected? (Select all that apply) quaternary tertiary primary secondary