Chapter 1:Facts of Life

Question 1

“Living things are composed of
lifeless molecules.”

Answer 1

Albert Lehninger. On life and Chemistry

Question 2

“…everything that living things do can be understood in terms of the jigglings and wigglings of atoms.”

Answer 2

Richard P. Feynman. On Life and Chemistry

Question 3

Distinctive Propertties of living organism

Answer 3

(1) Organisms are complicated and highly organized
(2) Biological structures serve functional purposes
(3) Living systems are actively engaged in energy transformations
(4) Living systems have a remarkable capacity for self-replication

Question 4

These macromolecules themselves show an exquisite degree of organization in their intricate three-dimensional architecture, even though they are composed of simple sets of chemical building blocks

Answer 4

(1) Organisms are complicated and highly organized

Question 5

It is this functional characteristic of biological structures that separates the science of biology from studies of the inanimate world such as chemistry and physics.

Answer 5

(2) Biological structures serve functional purposes

Question 6

s. In biology, it is always meaningful to seek the purpose of observed structures, organizations, or patterns

Answer 6

that is, to ask what functional role they serve within the organism.

Question 7

is moving to a condition of increasing disorder or, in
thermodynamic terms, maximum entropy

Answer 7

Inanimate matter

Question 8

Energy and material are consumed by the organism and used to maintain its

Answer 8

Stability and Order

Question 9

-simple division in bacteria
- sexual reproduction in plants and animals

Answer 9

(4) Living systems have a remarkable capacity for self-replication

Question 10

make up 99+% of atoms in the human body

Answer 10

H, O, C and N

Question 11

What property unites H, O, C and N and renders these atoms so appropriate to the chemistry of life?

Answer 11

Their ability to form covalent bonds by electron-pair
sharing.

Question 12

can share two electron pairs to
form double bonds with one another within biomolecules, a property that enhances their chemical versatility.

Answer 12

C, N, and O

Question 13

can form covalent bonds with itself + tetrahedral shape;

Answer 13

C

Question 14

Biomolecular Hierarchy

Answer 14

(1) Inorganic precursors
(2) Metabolites
(3) building blocks
(4) macromolecules
(5) supramolecular complexes
(6) organelles

Question 15

interactions among macromolecules result to the
formation of (5) supramolecular complexes

Answer 15

Non-covalent* interactions

Question 16

Simple molecules are the units for building complex structures

Answer 16

Biomolecular Hierarchy

Question 17

(1) Inorganic precursors

Answer 17

▪ Water (H2O)
▪ carbon dioxide (CO2)
▪ ammonium (NH4+)
▪ nitrate (NO3-)
▪ dinitrogen (N2)

Question 18

• simple organic compounds that are intermediates in cellular energy transformation and in the biosynthesis of various sets of building blocks

Answer 18

(2) Metabolites

Question 19

(3) building blocks

Answer 19

• amino acids
• sugars
• nucleotides
• fatty acids
• glycerol

Question 20

(4) macromolecules

Answer 20

• Protein
• Polysaccharides
• polynucleotides (DNA
  and RNA)
• lipids

Question 21

Non-covalent* interactions among macromolecules result to the formation of ____

Answer 21

(5) supramolecular complexes

Question 22

Non-covalent* interactions

Answer 22

• hydrogen bonds
• ionic attractions
• van der Waals forces
• hydrophobic interactions

Question 23

entities of considerable dimensions compared with the
cell itself.

Answer 23

(6) organelles

Question 24

(6) organelles

Answer 24

• Nucleus
• Mitochondria
• Chloroplasts
• endoplasmic reticulum
• Golgi apparatus
• Vacuoles
• other relatively small cellular inclusions such as peroxisomes,
  lysosomes, and chromoplasts

Question 25

are supramolecular assemblies that define the boundaries of cells

Answer 25

Membranes

Question 26

Membranes

Answer 26

▪ Membranes define the boundaries of cells and organelles
▪ not easily classified as supramolecular assemblies or organelles, although they share the properties of both
▪ resemble supramolecular complexes in their construction because they are complexes of proteins and lipids maintained by noncovalent forces

Question 27

Properties of Biomolecules: How Do the Properties of Biomolecules Reflect Their Fitness to the Living Condition?

Answer 27

There is a necessity for information and energy in the maintenance of the living state.
1. Some biomolecules must have the capacity to contain the information, or “recipe,” of life.
2. Other biomolecules must have the capacity to translate this information so that the organized structures essential to life are synthesized. Interactions between these structures are the processes of life.
3. An orderly mechanism for abstracting energy from the environment must also exist in order to obtain the energy needed to drive these processes.

Question 28

What properties of biomolecules endow them with the potential for such
remarkable qualities?

Answer 28

(1) Biological macromolecules and their building blocks have a “sense” or directionality
(2) Biological Macromolecules Are Informational

Question 29

result from the induced electrical interactions between closely approaching atoms or molecules

Answer 29

Van der Waals forces

Question 30

form between a hydrogen atom covalently bonded to an electronegative atom (such as oxygen or nitrogen) and a second electronegative atom that serves as the hydrogen bond acceptor

Answer 30

Hydrogen bonds

Question 31

cylindrically symmetrical
and tend to be highly directional, forming _________ between donor, hydrogen, and acceptor atoms.

Answer 31

straight bonds

Question 32

cylindrically symmetrical and tend to be highly directional, forming straight bonds between donor, hydrogen, and
acceptor atoms.

Answer 32

Hydrogen Bonds

Question 33

attractive forces between
oppositely charged
structures

Answer 33

Ionic interactions

Question 34

the electrical charge is
radially distributed, so
these interactions may
lack the directionality of
hydrogen bonds or the
precise fit of van der
Waals interactions

Answer 34

Ionic interactions

Question 35

Ionic interactions may involve

Answer 35

Ions
permanent dipoles
induced dipoles

Question 36

• species possessing discrete
  charges

Answer 36

Ions

Question 37

• having a
  permanent separation of positive
  and negative charge

Answer 37

permanent dipoles

Question 38

• having a temporary separation of positive and negative charge induced by the environment

Answer 38

induced dipoles

Question 39

result from the strong tendency of water to exclude nonpolar
groups or molecules

Answer 39

Hydrophobic interactions

Question 40

Without these interactions, the entropy of water is raised
because fewer water molecules are arranged in orderly arrays.

Answer 40

Hydrophobic interactions

Question 41

The defining concept of biochemistry is

Answer 41

“molecular recognition
through structural complementarity”

Question 42

The _____ and ____ patterns of life depend on the ability of biomolecules to recognize and interact with one another in very specific ways

Answer 42

complicated and highly organized

Question 43

Biological function is achieved through mechanisms based on ___ and ____.

Answer 43

structural complementarity and weak chemical interactions.

Question 44

supramolecular complexes occurs because of ___ and ____ , as governed by the weak forces formed between them.

Answer 44

recognition and interaction between their various macromolecular components

Question 45

Because biomolecular interactions are governed by ____ , living systems are _____ .

Answer 45

weak forces; restricted to a narrow range of physical conditions`