Deck 2: Cells and the Chemistry of Life

Question 1

Viruses are not considered to be living things, although they can evolve, and they do have genetic material. However, they

A)cannot reproduce on their own.
B)cannot cause disease.
C)possess a molecular structure entirely different from living cells.
D)do not possess DNA.
E)do not possess enzymes.

Answer 1

A

Question 2

Water is often known as a universal solvent, it dissolves polar molecules as well as

A)ionic compounds.
B)nonionic compounds.
C)hydrophobic compounds.
D)covalently bonded compounds.
E)lipids.

Answer 2

A

Question 3

An atom in which the number of electrons is different from the number of protons is called a(n)

A)ion.
B)molecule.
C)compound.
D)isotope.
E)acid.

Answer 3

A

Question 4

With few exceptions, organic compounds are those that contain

A)nitrogen.
B)hydrogen.
C)carbon.
D)oxygen.
E)all of the above.

Question 5

In an atom, the electrons are

A)housed within the nucleus.
B)moving through the nucleus.
C)present in various energy shells.
D)usually at rest, but occasionally move.
E)positively charged.

Question 6

Which of the following elements is not particularly abundant in living cells?

A)carbon
B)hydrogen
C)helium
D)nitrogen
E)oxygen

Question 7

The "bead" that allows the HIV particle to attach to and enter cells is

A)made of protein.
B)hidden within the virus particle.
C)part of the matrix of the virus.
D)made of RNA.
E)designed to protect the virus's RNA.

Question 8

Surface tension of water is due to

A)ionic bonding.
B)ionization of water.
C)the ability of water to act as a solvent.
D)hydrogen bonding.
E)water molecules repelling each other.

Question 9

Classes of lipids include all of the following except

A)phospholipids.
B)fats.
C)waxes.
D)carbohydrates.
E)steroids.

Question 10

Examples of polysaccharides include all of the following except

A)chitin.
B)glycogen.
C)cellulose.
D)sucrose.
E)starch.

Question 11

The internal pH of most cells is near neutral. This allows

A)water to break down into H⁺ and OH^-.
B)enzymes within the cells to act at peak efficiency.
C)the buffers produced within the body to affect these cells.
D)enzymes outside of these cells to function.
E)rapid fluctuations between acidic and basic conditions within the cells.

Question 12

Viruses are made of the same four types of biological molecules as living cells. These include all of the following except

A)lipids.
B)capsids.
C)carbohydrates.
D)proteins.
E)nucleic acids.

Question 13

This element is prominent in both living organisms and in the Earth's surface.

A)carbon
B)hydrogen
C)silicon
D)aluminum
E)oxygen

Question 14

Rank the following chemical bonds from weakest to strongest:

A)hydrogen, ionic, covalent
B)hydrogen, covalent, ionic
C)ionic, hydrogen, covalent
D)ionic, covalent, hydrogen
E)covalent, ionic, hydrogen

Question 15

The atomic nucleus consists of

A)neutrons and electrons.
B)neutrons only.
C)protons and electrons.
D)neutrons and protons.
E)protons only.

Question 16

Polypeptides consist of strings of amino acids held together by

A)ionic bonds.
B)hydrogen bonds.
C)peptide bonds.
D)double covalent bonds.
E)protein glues.

Question 17

Because the shared electrons between hydrogen and oxygen spend more time orbiting the oxygen than the hydrogen, water is

A)a charged molecule.
B)a neutral molecule.
C)a nonpolar molecule.
D)ionized.
E)a polar molecule.

Question 18

Kool-Aid readily dissolves in water. This means that Kool-Aid is

A)an acid.
B)hydrophilic.
C)hydrophobic.
D)a base.
E)a buffer.

Question 19

¹²C, ¹³C, and ¹⁴C are all isotopes of carbon. They differ in their

A)overall charges.
B)number of electrons.
C)number of protons.
D)number of neutrons.
E)electron energy shells.

Question 20

What method is often used by cells to move large solid material into the cell?

A)facilitated diffusion
B)exocytosis
C)simple diffusion
D)active transport
E)phagocytosis

Question 21

Describe the different distinct forms that regions of proteins can have. Why are these forms so important?

Question 22

Match the following components of HIV with the correct descriptive term:

Question 23

Most of a living organism (approximately 98%)is made up of what three elements?

Question 24

Match the following characteristics of atoms and molecules with the proper bond.

Question 25

Match the following descriptions with the appropriate mechanism of transport across the plasma membrane.

Question 26

Match the following examples with the correct cellular organelle.

Question 27

What differentiates various atoms?

Question 28

Although viruses exhibit some of the characteristics that define living organisms, they are considered nonliving. Explain why.

Question 29

Name a place in the human body that is particularly acidic. Where are fluids close to neutrality? Where are fluids in the human body particularly basic?

Question 30

Diagram an atom of nitrogen (which consists of 7 protons, 7 neutrons, and 7 electrons). Be sure to indicate in your illustration the relative size, position, and charge of the subatomic particles.

Question 31

How are viruses such as HIV similar to living things? How are they different?

Question 32

Match the following organic compounds with the appropriate subunit.

Question 33

How are the four major types of biological molecules similar in structure?

Question 34

Describe the primary components of an atom.

Question 35

The cells that line your small intestine absorb nutrients. Their cell membranes consist of many extensions and folds that project into the open space of the intestine. Why is this cell structure advantageous in the small intestine?

Question 36

Most cells are small. When they reach a certain size, cells typically divide. This has to do with the

A)amount of genetic material.
B)surface-to-volume ratio.
C)inability to produce more components of the cell membrane.
D)fact that they cannot possess sufficient numbers of organelles for normal cell functioning.
E)differences between viral particles and eukaryotic cells.

Question 37

What causes water molecules to form hydrogen bonds with each other?

Question 38

Because of the atomic structure of carbon, it tends to form

A)covalent bonds.
B)ionic bonds.
C)hydrogen bonds.
D)sulfide bonds.
E)bonds only with hydrogen.

Question 39

The HIV virus can take over much of the cell's machinery to produce many copies of the virus. Two classes of drugs that have been effective against HIV are base analogs (e.g., AZT)and protease inhibitors. How do these work to slow or stop HIV replication? What other steps in the HIV life cycle might be targets for drug development? What else can be done to try to stop the spread of HIV?

Question 40

Match the following characteristics or examples of organic molecules with the molecular classification.

Question 41

Given the half-life of radioactive carbon of 5730 years, if a sample from an archaeological site is analyzed, and it is determined to have 1/4 of the amount of ¹⁴C that a living organism would have, describe how you would go about aging this fossil.

Question 42

Think about your favorite kind of pizza. How is your body provided with each of the four major biological molecules when you eat this pizza? Why is it important that your food contains these biological molecules?

Question 43

Describe the theme you have learned in this chapter relating to monosaccharides, disaccharides, and polysaccharides. Relate this to what you have learned about lipids and proteins as well.

Question 44

Describe the unique nature of hydrogen bonds, and how this makes water such a unique, and biologically important molecule.