Chapter 3: The Importance of Weak and Strong Chemical Bonds

Question 1

Strong covalent bonds are …

Answer 1

1. Strong and stable to hold molecules together
2. Do not break spontaneously
3. short and covalent

Question 2

Van der waals, hydrophobic, hydrogen bonding and ionic are all _____ ____

Answer 2

Weak bonds

Question 3

True or False:

Weak bonds are important to secondary structure of macromolecules

Answer 3

FALSE

Weak bonds are important to TERTIARY structure of macromolecules

Question 4

Weak bonds can …

Answer 4

1. Form and break under physiological conditions (reversible)
2. Mediate internal interactions, enzymes/substrate and protein-DNA/RNA/protein interactions

Question 5

True or False:

Weak bonds are longer than stronger bonds

Answer 5

True

Question 6

________ is the number of covalent bonds that a given atom can make

Answer 6

Valence

Question 7

What is the bond angle?

Answer 7

The angle between two bonds originating from the same atom

Question 8

Explain bond rotation

Answer 8

Single covalent bonds permit free rotations of bound atoms, double bonds do not rotate

Question 9

Dextrose

Answer 9

Sugar

Question 10

L-Glucose

Answer 10

Cannot be phosphorylated by hexokinase

Question 11

A + B –> AB Energy

Answer 11

Spontaneous reaction

Releasing energy. Stronger the bond, greater the amount of energy, thus the more energy needed to break it

Question 12

AB + Energy –> A + B

Answer 12

Force exist to break bond using temperature or heat

Question 13

As the temperature of a collection of molecules is increased, the stability of their bonds _________

Answer 13

Decrease

Question 14

A + B –> AB + Energy

The equilibrium constant is …

Answer 14

[AB] / [A][B]

Question 15

The ______ the bond, the greater the amount of energy released upon its formation

Answer 15

Stronger

Question 16

When equilibrium is reached, the number of bonds forming per unit of time _______ the number of bonds breaking

Answer 16

Equals

Question 17

Endergonic Reaction

Answer 17

+G

Question 18

Exergonic Reaction

Answer 18

-G (favorable reaction)

Question 19

True or False:

All molecules can form van der waals

Answer 19

True

Question 20

Electrostatic attraction

Answer 20

All forms of weak interactions are based on attractions between electrical charges

Question 21

Hydrogen bonds are _______ than covakent bonds, but _______ than van der waals

Answer 21

weaker, stonger

Question 22

These types of bonds are directional

Answer 22

Hydrogen bonds

Question 23

These types of bonds contain one or more units of net charge, can form a salt bridge

Answer 23

Ionic bonds

Question 24

A weak covalent bond is called …

Answer 24

Disulfide bond

Question 25

Disulfide bridges are formed by

Answer 25

Two sulfur groups bonded to each other

Question 26

The weakest bond is called …

Answer 26

Van der waals

Question 27

Nonpolar molecules aggregate in water because ….

Answer 27

Water has lower disruption and higher entropy when nonpolar molecules are removed

Question 28

True or False:

Weak interaction require complementary molecular surfaces

Answer 28

True

Question 29

True or False:

Weak bonds mediate most protein-DNA and protein-protein interactions

Answer 29

True

Question 30

True or False:

Enzymes increases activation energies for molecular rearrangements

Answer 30

FALSE

Enzymes lower activation energies

Question 31

ATP hydrolysis is favorable because …

Answer 31

competing resonance between the phosphodiester bonds is relieved