Ch 4 - Carbon & Molecular Diversity of Life

Question 0

All living organisms are made of chemicals based mostly on the element carbon. Why?

Answer 0

Of any element, carbon has the greatest “flexibility” in forming molecules

Question 1

Organic chemistry

Answer 1

The study of carbon based compounds

Question 2

Certain substances, like graphite and diamonds, are made from pure carbon. If they are made from the same substance, why are they so different?

Answer 2

The carbon skeletons are different, making it possible for two very different materials to be formed from the same pure substance.

Question 3

Why is it possible for carbon atoms to form diverse molecules?

Answer 3

Carbon has 4 valence electrons, making it possible for binding with up to 4 other atoms; covalent capability with many different elements.

Question 4

What are a few elements that carbon can bind with?

Answer 4

Hydrogen (valence = 1)
Oxygen (valence =2)
Nitrogen (valence = 3)

Question 5

What are the 4 ways a molecule can be represented?

Answer 5

By its molecular formula (CO2), structural formula (O=C=O), a ball-and-stick model, it a space-filling model.

Question 6

In what ways can carbon skeletons vary?

Answer 6

Length, branching, position of double bonds, & ring structure.

Question 7

What are carbon skeletons the basis if?

Answer 7

Organic compounds

Question 8

Hydrocarbons

Answer 8

Molecules consisting of only carbon and hydrogen; a component of many cellular organic molecules.

Question 9

Examples of hydrocarbons

Answer 9

A fat molecule has hydrocarbon tails.

Mammalian fat cells.

Question 10

Isomers

Answer 10

Molecules with the same molecular formula but different structures and properties

Question 11

3 types of isomers

Answer 11

Structural isomers, geometric isomers, and enantiomers

Question 12

Structural isomers

Answer 12

Differ in arrangement atoms; possibilities increase with the size of the carbon skeleton

Question 13

Geometric isomers

Answer 13

Have the same covalent partnerships, but differ in spatial arrangements around a double bond. These include CIS and TRANS (across, through, between) geometries with different biological properties.

Question 14

Enantiomers

Answer 14

Isomers that are still mirror images of each other. “Left-handed” and “right-handed”.

Question 15

Functional groups

Answer 15

The parts of molecules involved in chemical reactions; “additions” to a carbon skeleton in an organic molecule.

Question 16

6 functional groups important to life

Answer 16

Hydroxyl, Carbonyl, Carboxyl, Amino, Sulfhydryl, and Phosphate

Question 17

Hydroxyl group (formula and compounds)

Answer 17

A hydrogen atom is bonded to an oxygen atom, which in turn is bonded to a carbon skeleton of the organic molecule (NOT the hydroxide ion OH-)

Formula: –OH

Compounds: Alcohol

Question 18

Carbonyl group (formula and compounds)

Answer 18

A carbon atom bonded to an oxygen atom by a double bond

Formula: =O Compound:

          - -C             Aldehydes 
               - -H

Formula: O Compound:
= Ketones
–C–

Question 19

Hydroxyl (general)

Answer 19

Polar; can form hydrogen bonds with water and help dissolve organic molecules.

Question 20

Carbonyl (general)

Answer 20

Ketones if the carbonyl group is within a carbon skeleton.

Aldehyde if the carbonyl groups is at the end of a carbon skeleton.

Question 21

Carboxyl (formula and compounds)

Answer 21

An oxygen atom is joined to a carbon atom by a double bond which is in turn bonded to an OH

Formula: =O =O
–C –C
–OH –O(-)
(non-ionized) (ionized)

Compounds: Carboxylic acids (organic acids)

Question 22

Carboxyl groups (general)

Answer 22

Acts as an acid because the covalent bond between oxygen and hydrogen is so polar.

Question 23

Amino groups (formula and compounds)

Answer 23

A nitrogen atom bonded to two hydrogen atoms and to the carbon skeleton

Formula: –H –H
–N –(+)N
–H –H
(non-ionized) (ionized)

Compounds: Amines

Question 24

Amino groups (general)

Answer 24

Acts as a base

Question 25

Sulfhydryl groups (formula and compounds)

Answer 25

A sulfur atom bonded to a hydrogen atom
Formula: –SH
Compounds: Thiols

Question 26

Sulfhydryl groups (general)

Answer 26

2 sulfhydryl groups can react to form a cross-linking covalent bond

Question 27

Phosphate groups (formula and compounds)

Answer 27

A phosphorus atom is bonded to four oxygen atoms (1 oxygen is bonded to the carbon skeleton; 2 oxygens carry negative charges)

Formula:           O
                         =
                 --O--P--O(-)
                         --
                         O(-)
Compounds: Organic phosphates

Question 28

Phosphate groups (general)

Answer 28

Can react with water, releasing energy

Question 29

Vitalism

Answer 29

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

This provided the foundation for new discipline of organic chemistry.

Question 30

What four elements compose 96% of living organisms?

Answer 30

Hydrogen
Carbon
Nitrogen
Oxygen

Question 31

Cis-Trans isomers

Answer 31

Carbons have covalent bonds to the same atoms, but these atoms differ in their spacial arrangements due to the inflexibility of double bonds.

Trans - Across, through, between
Cis - Run

Question 32

Adenosine Triphosphate (ATP)

Answer 32

An adenine-containing nucleoside triphosphate that releases free energy when its phosphate bonds are hydrolyzed.

This energy is used to drive endergonic reactions in cells.