Ch.2 Anatomy

Which of the following statements about chemical bonds is true?

Covalent bonds are stronger than ionic bonds.

The characteristic that gives an element its distinctive properties is its number of

H2

Uracil

all of the above

When an atom donates an electron to another atom, it becomes

an ion

The smallest unit of an element that still retains the distinctive behavior of that element is an

atom

AB→A+B is a general notation for a(n) ________ reaction.

decomposition

In DNA, nucleotide bonding forms a compound with a characteristic shape known as a(n) ________.

double helix

A phospholipid

has both polar and nonpolar regions

Which of the following combinations of atoms is most likely to result in a chemical reaction?

hydrogen and hydrogen

A pentose sugar is a part of the monomer used to build which type of macromolecule?

nucleic acids

CH4 is methane. This compound is

organic

Together, just four elements make up more than 95 percent of the body's mass. These include

oxygen, carbon, hydrogen, and nitrogen

A molecule of ammonia contains one atom of nitrogen and three atoms of hydrogen. These are linked with

polar covalent bonds

The energy stored in a foot of snow on a steep roof is

potential energy

A substance dissociates into K+ and Cl- in solution. The substance is a(n) ________

salt

The ability of an enzyme's active sites to bind only substrates of compatible shape and charge is known as ________.

specificity

Nitrogen has an atomic number of seven. How many electron shells does it likely have?

two

Which of the following is a functional group that is part of a building block of proteins?

amino

What organic compound do brain cells primarily rely on for fuel?

glucose

On the periodic table of the elements, mercury (Hg) has an atomic number of 80 and a mass number of 200.59. It has seven stable isotopes. The most abundant of these probably have

more than 80 neutrons each

The characteristic that gives an element its distinctive properties is its number of

protons

Chewing a bite of bread mixes it with saliva and facilitates its chemical breakdown. This is most likely due to the fact that

saliva contains enzymes

A substance formed of crystals of equal numbers of cations and anions held together by ionic bonds is called a(n)

salt

Jenny mixes up a batch of pancake batter, then stirs in some chocolate chips. As she is waiting for the first few pancakes to cook, she notices the chocolate chips sinking to the bottom of the clear glass mixing bowl. The chocolate-chip batter is an example of a

suspension