Chapter 2 - Chemistry of Life

Question 1

How do the structure of atoms change as you move through the periodic chart?

Answer 1

AToms will get larger in size as well as having more shells/electrons.

Question 2

How electrons affect an atom’s ability to interact with another atom and form bonds.

Answer 2

Atoms form bonds with each other by the amount of valence (unpaired electrons in the outermost shell) that they have. The more unpaired valence electrons, the more bonds they can form.

Question 3

Discrete energy levels in which electrons orbit the nucleus of an atom.

Answer 3

These orbits form electron shells or energy levels, which are a way of visualizing the number of electrons in the outermost shells. These energy levels are designated by a number and the symbol “n.”

Question 4

How isotopes differ from each other, and explain why they can be used in biology.

Answer 4

Isotopes are the same elements with different amounts of neutrons, making them have different atomic masses.
Isotopes are often used to determine how old something is using Carbon-14 isotope.

Question 5

What is electronegativity?

Answer 5

Some atoms attract electrons more than others.
The more electronegative an atom, the more strongly it pulls shared electrons towards itself.

Question 6

Compare/Contrast covalent and ionic bonds.

Answer 6

Covalent bonds are formed when atoms share pairs of valence electrons.
Ionic bonds are formed between ions, cations, and anions.

Question 7

Compare/contrast polar and non-polar covalent bonds and be able to recognize them.

Answer 7

A polar covalent bond is formed between two or multiple atoms with different electronegativity, resulting in one attracting the shared electron towards itself more, making itself more negative, and making the molecule polar.
A non-polar covalent bond is formed when two or more atoms with the same electronegativity share electrons. Since none of them attract electrons more than the others, the shared electron will stay in the middle, none will have charges.

Question 8

What are hydrogen bonds and van der Waals interactions and be able to recognize them?

Answer 8

Van der Waal’s Interaction occurs when 2 or more polar molecules attract each other but aren’t strong enough to form bonds.
Hydrogen bond is one type of Van der Waal’s interaction which involves a hydrogen atom.

Question 9

Explain the relevance of water’s unusual properties for living systems.

Answer 9

The polarity of water allows many chemical reactions to happen in nature.

Question 10

Explain how hydrogen bonds affect the structure and behavior of water.

Answer 10

Since the hydrogen bond is a weak bond, it allows water molecules to break apart and reform easily, which is why water can split and come back as if nothing ever happened.

Question 11

Describe water’s cohesive and adhesive properties with examples.

Answer 11

Cohesive: having hydrogen bonds allows water molecules to stick together. One example is surface tension, water molecules hold each other through the hydrogen bond before breaking apart from too much tension.
Adhesive: The polarity of water allows water to stick to other different molecules from its surroundings.

Question 12

Define hydrophilic and hydrophobic

Answer 12

Hydrophilic is susceptible to water while hydrophobic is repelled against water

Question 13

Calculate the pH of a solution and convert between pH, OH-, and H+ concentrations.

Answer 13

pH = negative of the base 10 logarithm of the [H+], also written as pH = -log10 [H+]
The log_10 of 1 X 10^-7 is -7, and the
negative of that number is 7

Question 14

Describe the properties of water that make it an ideal solvent for biological reactions.

Answer 14

Because water is polar, with slight positive and negative charges, ionic compounds and polar molecules can readily dissolve in it

Question 15

The dissociation products of water.

Answer 15

A small percentage of water molecules dissociate (ionize) into an equal number of hydrogen ions (H+) and hydroxide ions (OH-).

Question 16

Explain the nature of acids and bases and their relationship to the pH scale.

Answer 16

pHs of less than 7 indicate acidity, whereas a pH of greater than 7 indicates a base.
Soapy water has a pH of 12 (basic)
Lemon juice has a pH of 2-3(acidic)

Question 17

Explain the relationship between pH and hydrogen ion concentration

Answer 17

Solutions with high H+ concentrations are acidic (low pH)

Question 18

Explain how buffers maintain a stable environment.

Answer 18

Buffers are weak acids or weak bases
that help solutions resist changes in pH

Question 19

The carbonic acid buffer system and know how it works.

Question 20

Explain Ocean Acidification and connect the reactions to what occurs in ocean vs. what occurs in our blood.

Question 21

Describe the hypothesis, experimental setup, and the results from the Miller-Urey experiment.

Question 22

Explain the properties of carbon that make it the focal point of organic compounds.

Question 23

Recognize, compare and contrast structural isomers.

Question 24

Recognize, compare and contrast cis and trans isomers.

Question 25

Recognize, compare and contrast enantiomers.

Question 26

Recognize asymmetric carbons in a compound.

Question 27

Recognize common functional groups in a compound.

Answer 27

Functional Groups: hydroxyl, methyl, carbonyl, carboxyl, amino, phosphate, and sulfhydryl

Question 28

Hydroxyl

Answer 28

Structure:
O — H
/
R
Properties: Polar, hydrophilic
Found in: Sugar and alcohol

Question 29

Carbonyl

Answer 29

Structure:
R — C = O
/
R
Properties: Polar
Function:
Found in: Every Sugar

Question 30

Carboxyl

Answer 30

Structure:
R — C = O
\
OH
Properties:
Function:
Found in:

Question 31

Methyl

Answer 31

Structure:
R — CH3
Properties:
Function:
Found in:

Question 32

Amino

Answer 32

Structure:
R — NH2
Properties:
Function:
Found in:

Question 33

Phosphate

Answer 33

Structure:
O
||
R — O — P — O-
|
O-
Properties:
Function:
Found in:

Question 34

Sulfhydryl/Thiol

Answer 34

Structure:
R — SH
Properties:
Function:
Found in:

Question 35

Explain how the structure of a carboxyl group allows it to function as an acid

Question 36

How an amino group allows it to function as a base.