Review of Chemical Principles in Mol Bio

Question 1

What are biological molecules comprised of?

Answer 1

atoms

Question 2

What do atoms contain?

Answer 2

subatomic particles

Question 3

What is the structure of atoms?

Answer 3

neutrons and protons are at the atomic nucleus, with electrons surrounding the nucleus

Question 4

What charge are protons?

Answer 4

positively charged

Question 5

What charge are neutrons?

Answer 5

neutral

Question 6

What charge are electrons?

Answer 6

negatively charged

Question 7

What is the atomic number?

Answer 7

the number of protons

Question 8

What is the atomic mass?

Answer 8

the number of protons + the number of neutrons

Question 9

What determines the interactions with other atoms?

Answer 9

arrangement of electrons

Question 10

Where are electrons found?

Answer 10

in separate “shells” surrounding the nucleus

Question 11

How many electrons fill each shell?

Answer 11

the innermost shell contains up to 2 electrons, the second and third shells contain 8 electrons

Question 12

What shell is most stable and chemically unreactive?

Answer 12

the outermost shell filled

Question 13

What makes atoms more stable?

Answer 13

if an outer electron shell is unfilled, atoms can share electrons to complete their outer shells

Question 14

What forms covalent bonds?

Answer 14

sharing of electrons forms covalent bonds

Question 15

What is a single bond?

Answer 15

where one electron from each atom is shared

Question 16

When do multiple bonds form?

Answer 16

when more than one electron is shared

Question 17

T or F: covalent bonds are very stable

Answer 17

true

Question 18

What do covalent bonds form?

Answer 18

strict geometrical configurations characteristic of the atoms involved

Question 19

What shape is formed from a carbon with four single bonds?

Answer 19

they are equally spaced from one another in a tetrahedron, as in methane

Question 20

T or F: atoms cannot rotate freely about a single bond

Answer 20

true

Question 21

T or F: atoms can rotate freely about a double bond

Answer 21

false; rotation of atoms around the bond is restricted, so other bonds are in a single plane, as in ethene

Question 22

What are peptide bonds?

Answer 22

covalent bonds that form between amino acids to form polypeptides( chains of amino acids) and proteins

Question 23

What atoms are in peptide bonds?

Answer 23

three covalent bonds are shared between the O, C, and N atoms of the bond

Question 24

What are the bonds between C, O, C, and N in peptide bonds?

Answer 24

both have partial double bond character

Question 25

How do partial double bonds affect rotation in peptide bonds?

Answer 25

restricts rotation at the bond and is crucial for protein structure and function

Question 26

What is electronegative?

Answer 26

the atom with the greater share of the electron is partially negatively charged

Question 27

What is electropositive?

Answer 27

the atom with the lesser share

Question 28

What is a dipole?

Answer 28

separation of charge between electrons shared unequally within a covalent bond

Question 29

What are polar bonds?

Answer 29

covalent bonds with a dipole

Question 30

What are non-polar bonds?

Answer 30

covalent bonds that do not have any charge separation

Question 31

T or F: polar molecules interact favorably with water

Answer 31

true

Question 32

T or F: non-polar molecules interact favorably with water

Answer 32

false

Question 33

What is the polarity of water?

Answer 33

O has a partial negative charge and the H atoms are partially positive

Question 34

What are anions?

Answer 34

negative charged ions

Question 35

What are cations?

Answer 35

positive charged ions

Question 36

What are ionic bonds?

Answer 36

charged ions interact very strongly with one another, such as sodium chloride

Question 37

T or F: charged chemical groups do not have ionic interactions

Answer 37

false

Question 38

What does ionized water become?

Answer 38

hydroxide and hydronium ions

Question 39

What is the concentration of pure water?

Answer 39

OH- and H3O is 10^-7 each M, 10^-14 in product

Question 40

What are acids?

Answer 40

molecules that release H+

Question 41

What are bases?

Answer 41

molecules that accept H+

Question 42

What affects biological reactions?

Answer 42

the concentration of H+

Question 43

What is the pH of lyzosomes?

Answer 43

~5

Question 44

What are non-covalent bonds?

Answer 44

mostly weaker than covalent bonds but have important roles in molecular structure and stabilization

Question 45

What allows molecules to be flexible for function?

Answer 45

weaker bonds can be formed and broken

Question 46

T or F: non-covalent reactions are fundamentally electrostatic interactions

Answer 46

true

Question 47

What are salt bridges

Answer 47

ionic interactions between charged atoms plus an H-bond

Question 48

What are hydrogen bonds?

Answer 48

interactions between polar atoms with partial charges, mediated by one hydrogen atom

Question 49

What are van der Waals interactions?

Answer 49

weak attractions between atoms at a certain distance

Question 50

T or F: ionic bonds are very stable and strong in the absence of water

Answer 50

true

Question 51

What weakens ionic bonds?

Answer 51

polar water molecules which interact with the charges

Question 52

What are hydrophobic molecules?

Answer 52

non-polar molecules that do not interact favorably with water

Question 53

How do hydrophobic interactions drive molecular folding?

Answer 53

1. hydrophobic regions associated with one another and exclude water 2. hydrophilic regions tend to located on outer surfaces of molecules where the interact with water

Question 54

T or F: multiple weak bonds combine to produce stable yet potentially dynamic associations between macromolecules

Answer 54

true