(Unit 1) Chapter 4: Carbon and the Molecular Diversity of Life

Question 1

What element accounts for the large diversity of biological molecules?

Answer 1

Carbon

Question 2

Define:

Organic Chemistry

Answer 2

The branch of chemistry that specializes in the study of carbon compounds

Question 3

What are the major elements of life? (6)

Answer 3

Hydrogen (H)
Oxygen (O)
Nitrogen (N)
Sulfur (S)
Phosphorus (P)
Carbon (C)

Question 4

Who made the distinction between organic compounds (those only from living organisms) and inorganic compounds (those only found in the non-living world)?

Answer 4

Jons Jakob Berzelius, Swedish chemist

Question 5

Define:

Vitalism

Answer 5

The belief in a life force outside the jurisdiction of physical and chemical laws

Question 6

What did vitalism eventually shift to, the new stream of biological thought?

Answer 6

Mechanism

Question 7

Define:

Mechanism

Answer 7

The view that physical and chemical laws govern all natural phenomena, including the processes of life

Question 8

What did Friedrich Wohler create from mixing solutions of ammonium ions and cyanate ions?

Answer 8

Urea

Question 9

What did Hermann Kolbe create from mixing inorganic substances?

Answer 9

Acetic acid

Question 10

Define:

Abiotic

Answer 10

Nonliving

Question 11

Carbon has _ electrons, with _ in the first electron shell and _ in the second shell

Answer 11

6
2
4

Question 12

This ____________ is one facet of carbon’s versatility that makes large, complex molecules possible

Answer 12

Tetravalence

Question 13

When a carbon atom has four single bonds to other atoms, the molecule is ___________

Answer 13

Tetrahedral

Question 14

True or False:

A carbon molecule may have more than one tetrahedral group of single-bonded atoms

Answer 14

True

Question 15

When two carbon atoms are joined by a double bond, what shape is the molecule?

Answer 15

The molecule is flat, as all atoms attached to those carbons are in the same plane

Question 16

What are certain variations in the carbon skeletons of organic molecules? (4)

Answer 16

Length: May vary in length
Branching: May be branched or unbranched
Double bonds: May have double bonds, may vary in location
Rings: May be arranged in rings

Question 17

Define:

Hydrocarbons

Answer 17

Organic molecules composed of only carbon and hydrogen

Question 18

What shape is methane (CH4)?

Answer 18

Tetrahedral, as it has four single bonds to the hydrogens

Question 19

What shape is ethane (C2H6)?

Answer 19

Double tetrahedral, like two methane bonded together

Question 20

What shape is ethene/ethylene (C2H4)?

Answer 20

Flat, as there is a double bond between the carbons

Question 21

Though hydrocarbons aren’t prevalent in living organisms, what is an example where they occur?

Answer 21

On the tails of fats, accounting for the fat’s hydrophobic properties and use for energy

Question 22

Define:

Isomers

Answer 22

Compounds that have the same numbers of atoms of the same elements but different structures and hence different properties

Question 23

Define:

Structural Isomers

Answer 23

Differ in the covalent arrangements of their atoms

Question 24

True or False:

The number of possible isomers increases tremendously as carbon skeletons increase in size

Answer 24

True

Question 25

True of False: | Structural isomers are only different in the arrangements of their atoms

Answer 25

False, structural isomers may also differ in the location of double bonds

Question 26

Define: | Geometric Isomers

Answer 26

Have the same covalent partnerships, but they differ in their spatial arrangements

Question 27

Geometric isomers differ in the arrangement around what?

Answer 27

Double bonds

Question 28

If two atoms/group of atoms are on the same side of the double bond, what kind of a geometric isomer is this?

Answer 28

Cis isomer

Question 29

If two atoms/group of atoms are on opposite sides of the double bond, what kind of a geometric isomer is this?

Answer 29

Trans isomer

Question 30

Define: | Enantiomers

Answer 30

Isomers that are mirror images of each other

Question 31

What types of enantiomers are there?

Answer 31

L and D isomers (stands for levo and dextro, Latin for left and right respectively)

Question 32

Where is the concept of enantiomers important? Why?

Answer 32

The pharmaceutical industry | Two enantiomers of a drug may not be equally effective (e.x. S-Ibuprofen is effective whereas R-Ibuprofen)

Question 33

Define: | Functional groups

Answer 33

The different chemical groups that affect the molecular function (e.x. affecting the chemical's shape or how it reacts in a reaction)

Question 34

What are the seven most important chemical groups in biological processes? (7)

Answer 34

``` Hydroxyl Carbonyl Carboxyl Amino Sulfhydryl Phosphate Methyl ```

Question 35

True or False: | Hydroxyl, carbonyl, carboxyl, amino, sulfhydryl, and phosphate groups can act as functional groups

Answer 35

True

Question 36

Hydroxyl, carbonyl, carboxyl, amino, sulfhydryl, and phosphate groups are also ___________

Answer 36

Hydrophilic, thus increase the solubility of organic compounds in water

Question 37

The methyl group is not ________, but instead often acts as a recognizable ___ on biological molecules

Answer 37

Reactive | Tag

Question 38

List the structure, name, example, and functional properties (2) of: Hydroxyl groups

Answer 38

OH group, hydrogen bonded to oxygen bonded to carbon skeleton Alcohols (names usually end in -ol) Ethanol Polar as electrons spend more time near electronegative oxygen atom, can form hydrogen bonds with water molecules (helps dissolve organic compounds such as sugar)

Question 39

List the structure, name (2), examples (2), and functional properties (2) of: Carbonyl groups

Answer 39

Oxygen double bonded to a carbon atom Ketones (if within carbon skeleton), Aldehydes (if at end of carbon skeleton) Acetone, Propanal Ketones and aldehydes may be structural isomers with different properties (e.x. acetone and propanal), found in sugars (giving rise to two major groups of sugars: aldoses (aldehydes) and ketoses (ketones))

Question 40

List the structure, name, example, and functional properties (2) of: Carboxyl groups

Answer 40

Oxygen double bonded to a carbon atom that is also bonded to an OH group Carboxylic acids, or organic acids Acetic acid Has acidic properties (source of H+ ions), found in cells in the ionized form with a charge -1 (called carboxylate ion)

Question 41

List the structure, name, example, and functional properties (2) of: Amino groups

Answer 41

Nitrogen atom bonded to two hydrogen atoms and to the carbon skeleton Amines Glycine (an amino acid, as it also has a carboxyl group) Acts as a base (can pick up H+ from surrounding solution, water in living organisms), ionized with a charge 1+ under cellular conditions

Question 42

Compounds with both amino and carboxyl groups are known as what?

Answer 42

Amino acid

Question 43

List the structure, name, example, and functional properties (2) of: Sulfhydryl groups

Answer 43

Sulfur bonded to hydrogen atom, bonded to a carbon skeleton Thiols Cysteine (also an amino acid) Two sulfhydryl groups can react and form a covalent bond (helps stabilize protein structure), this cross-linking maintains the curliness or straightness of hair

Question 44

What is the covalent bond formed between two sulfhydryl groups called?

Answer 44

"Cross linking"

Question 45

List the structure, name, example, and functional properties (2) of: Phosphate groups

Answer 45

``` 1 phosphorus bonded to 4 oxygen, with one oxygen bonded to the carbon atom (2 oxygens have negative charge) Organic phosphates Glycerol phosphate (takes part in many reactions in cells, backbone of phospholipids) Contributes negative charge to the molecule which it is a part of (-2 when at end, -1 when in the middle of a chain of phosphates), has potential to react with water (releasing energy) ```

Question 46

List the structure, name, example, and functional properties (2) of: Methyl groups

Answer 46

1 carbon bonded to 3 hydrogens, bonded to the carbon chain Methylated compounds 5-methyl cytidine (component of DNA modified by addition of methyl group) Addition of this group to DNA affects expression of genes, arrangement in male and female sex hormones affect their shape and function

Question 47

What is an important source of energy for cellular processes?

Answer 47

ATP (Adenosine triphosphate)

Question 48

What is ATP?

Answer 48

Organic molecule adenosine attached to a string of three phosphate groups

Question 49

State the reaction the ATP undergoes

Answer 49

ATP reacts with water; 1 phosphate group splits off as a result and releases energy

Question 50

After 1 phosphate group splits off of ATP, what is it now known as

Answer 50

ADP (Adenosine diphosphate, as there is only two phosphates left)