Unit 2- Chemistry And Macromolecules

Question 1

Elements

Answer 1

Substance that cannot be broken down to other substances by normal chemical means . There are 118 elements, 92 elements are found in nature.

Question 2

Compound

Answer 2

A substance consisting of two or more elements combined in a fixed ratio

Question 3

How many elements are necessary for life

Answer 3

Depends on the organisms

Plant; 17elements
Humans ; 25 elements

Question 4

The Big six ( elements that makes up 99% of the matter in our bodies)

Answer 4

Oxygen (o)
Nitrogen (N)
Hydrogen (H)
Carbon (C)
Calcium (Ca)
Phosphorus (P)

Question 5

Isotopes

Answer 5

Atom that has the same number of protons and behaves the same way chemically but have different numbers of neurons

Question 6

Radioactive isotope

Answer 6

The nucleus is unstable causing it to decay spontaneously, releasing particles and the energy (radiation)

Question 7

Inert Atoms

Answer 7

Atoms that have complete outershell

Question 8

Chemical reaction

Answer 8

Chemical reaction occurs when two atoms with incomplete outer shells interacts

Question 9

Water Cohesion

Answer 9

Cohesion is the tendency of molecules of the same type to stick together due to hydrogen bonds

Question 10

Thermal energy

Answer 10

Energy associated Witt Radom movement of atoms and molecules

Question 11

Heat

Answer 11

Thermal energy transferring from a warmer body of matter to a cooler body of matter

Question 12

Temperature moderation

Answer 12

1. Warm molecules move quickly than cold molecules
2. Hydrogen bonds need to be broken to allow molecules to move more quickly.
3. Water absorbs large amount of heat to break its bonds before temperature actually increases

Question 13

Isomers

Answer 13

Compounds with the same chemical formula but different structural arrangements

Question 14

Carbon skeleton

Answer 14

The chain of carbon atoms that forms the backbone of an organic molecule

Question 15

Hydrocarbons

Answer 15

Molecules that consists of only carbon and hydrogen e.g Methane

Question 16

Chemical group

Answer 16

Atoms that are attached to carbon skeleton

Question 17

Chemical groups

Answer 17

1. Hydroxyl: Alcohol
2. Carbonyl: simple sugar all contain carbonyl
3. Carboxyl: these can donate an H+ to a solution making it acidic
4. Amino group: pick up an H+ from solution to become ionized and are called amines
5. Phosphate group: often ionized because O atoms are negative. These organic phosphate are involved in energy transfers
6. Methly group: affects the expression of genes.

Question 18

Functional group

Answer 18

Chemical groups that affect a molecule’s function by participating in chemical reactions
1. Polar groups; soluble in water
2. Non- polar group: not water soluble

Question 19

Classes of Molecules

Answer 19

1. Macromolecules e.g lipids, Carbohydrates, proteins, nucleic acids
2. Polymers: small molecules joined together
3. Monomers the building blocks of polymers.

Question 20

What are the classes of molecules ?

Answer 20

Monomers; they are building blocks for polymers
Polymers; They make up the macromolecules, small molecules joined together in chains
Macromolecules; they are very large molecules e.g Carbohydrate, lipids, proteins and nucleic acids