Chapter 2

Question 1

What are elements?

Answer 1

Elements contain only one type of atom Pure substances that cannot be broken down

• 118 known elements:
• 94 occur naturally.
• 24 have been created artificially in the laboratory.

Question 2

what’s a positively charged ion?

Answer 2

atom that lost electron

Question 3

what’s a negatively charged electron?

Answer 3

atom that gained electron

Question 4

what do protons + electrons contribute to?

Answer 4

charge

Question 5

define orbital

Answer 5

region where electron is found at least 90
percent of the time

Question 6

what are reactive atoms?

Answer 6

have unpaired electrons in their outermost (valence) shell.

Question 7

what are chemical bonds?

Answer 7

attractive force that links atoms together to form molecules

Question 8

define covalent bonds

Answer 8

Can share valence electrons

Covalent bonds are very strong—a lot of energy
is required to break them.

Question 9

define ionic bonds

Answer 9

Ionic bonds are formed by the electrical attraction of
positive and negative ions.

Eg- NaCl

Question 10

define nonpolar covalent bonds

Answer 10

A covalent bond between atoms that have the
same, or nearly the same, electronegativity is a
nonpolar covalent bond.

atoms share the electrons equally.

Question 11

is water polar or non polar

Answer 11

polar molecule

Question 12

pH of water?

Answer 12

7

Question 13

mention some uniquely unusual properties of water

Answer 13

1. Moderation of Temperature
2. Cohesion & Adhesion
3. Ability to Act as an Insulator
4. Ideal Solvent
5. Weak Acid

Question 14

what type of bonds is present in water?

Answer 14

Hydrogen bonds

Question 15

Due to which of water’s properties does earth maintain a moderate temperature?

Answer 15

high heat capacity - moderation of temperature

Question 16

explain cohesion in water

Answer 16

water molecules resist coming apart
from one another.
• Results in surface tension.
• Helps water move through plants (wicking)

Question 17

what are the 4 major elements?

Answer 17

C,O,H,N

Question 18

special property of Carbon?

Answer 18

Carbon is 47% of that dry mass. Carbon has the unique
ability to combine with a wide variety of molecules

Question 19

what are organic molecules?

Answer 19

molecules that contain carbon

Question 20

carbon containing molecules are very diverse

true or false

Answer 20

true

Question 21

define isomers

Answer 21

Two molecules with the same chemical formula may
be arranged differently

Question 22

subunits of proteins?

Answer 22

amino acids

Question 23

main function of functional groups and some examples

Answer 23

add chemical character to carbon chains

Question 24

what are the subunits of nucleic acids such as DNA or RNA called?

Answer 24

nucleotides

Question 25

name the 3 components of nucleotides

Answer 25

five-carbon sugar (ribose or deoxyribose) base containing nitrogen one or more phosphate groups

Question 26

how does the sugars differ in nucleotides?

Answer 26

The sugars differ only by the OH group or H group at the 2′ carbon

Question 27

name the pyramidine bases

Answer 27

Cytosine C Uracil U Thymine T

Question 28

name the purine bases

Answer 28

Guanine G Adenine A

Question 29

what's the bond between nucleotides called?

Answer 29

Phosphodiester bond

Question 30

give carbohydrates structure

Answer 30

C₆H₁₂O₆

Question 31

what are the types of sugar molecules?

Answer 31

cyclic glucose linear glucose

Question 32

what's name of the bond that holds carbohydrates?

Answer 32

Glycosidic bonds

Question 33

how are lipds made?

Answer 33

fatty acids

Question 34

what's a triacylglycerol?

Answer 34

formed by addition of 3 fatty acid chains to glycerol

Question 35

what's an unsaturated fatty acid?

Answer 35

contains one/ more carbon, double bonds

Question 36

what are van der waal's forces?

Answer 36

Question 37

How are steroids formed?

Answer 37

Steroids are composed of many carbon atoms bonded to form rings. Eg- Cholesterol (a steroid) is a precursor steroid hormones such as estrogen and testosterone.

Question 38

what are phospholipids?

Answer 38

contains hydrophillic head and hydrophobic tails

Question 39

Could these building blocks have been generated on early earth?

Answer 39

Question 40

How did the building blocks form macromolecules?

Answer 40