Ch 2 - Self test Flashcards
anything that occupies space and has mass is called__
matter
a pure substance that is composed of only one of more than a hundred types of atoms is called a(n):
element
A chemical bond formed by the sharing of one or more pairs of electrons between the outer shells of two atoms is called a(n):
covalent bond
Molecules that form ions when dissolved in water are called:
electrolytes
acids:
release hydrogen ions (higher hydrogen concentration); have a pH below 7
As the concentration of hydrogen ions increases, the pH goes:
down and the solution becomes more acidic.
buffers:
maintain pH balance
The carbon-containing molecules formed by living things are often called:
organic molecules
Each enzyme “fits” the specific molecule it works on. This explanation is often referred to as the:
lock and key model
The most important monosaccharide, which is used by cells as their primary source of energy, is:
glucose
An example of a polysaccharide is:
glycogen
proteins are large molecules composed of
amino acids
Which of these is not a lipid?
a. Fat
b. Steroid
c. Cholesterol
d. Polysaccharide
d. polysaccharide
A very large molecule composed of a phosphate unit, a sugar, and a nitrogen base is a:
nucleic acid
DNA and RNA are important because:
they are the “master code” for assembling proteins and other nucleic acids.
