Chapter 2 (Chemistry)

Question 1

Define atom

Answer 1

the smallest chemical unit of matter

Question 2

Define molecule

Answer 2

two or more atoms held together by chemical bonds

Question 3

Define compound

Answer 3

a molecule containing atoms of more than 1 element

Question 4

Define element

Answer 4

matter that is composed of a single type of atom

Question 5

Define dehydration synthesis

Answer 5

-reactions that make macromolecules
-dehydration=removing water synthesis= making
(H2O would be at the end need energy)

Question 6

Define hydrolysis

Answer 6

-reactions that break macromolecules
-hydro (water) -lysis (to break or cut)/ release energy

Question 7

Define inorganic

Answer 7

-molecule lacking carbon

Question 8

Define organic compound

Answer 8

-molecules that contain both carbon & hydrogen atoms

Question 9

Define hydrophobic

Answer 9

-“water fearing/hating)
-does not dissolve in water

Question 10

Define hydrophilic

Answer 10

-“water loving”
-does dissolve in water

Question 11

Describe the parts of an atom

Answer 11

Protons (in nucleus of atom), neutrons (in nucleus of atom has no charge ), electrons

Question 12

What are the elements commonly found in living organisms?

Answer 12

CHONPS
Carbon
Hydrogen
Oxygen
Nitrogen
Phosphorus
Sulfur

Question 13

Compare/Contrast ionic, covalent, hydrogen bonds
Which is the strongest? Weakest?

Answer 13

Ionic bond: bond holding Na+ and Cl- ions in NaCl
Covalent bond: bonds holding hydrogen & oxygen atoms in 1
molecule of H2O (shraing of pair of electrons
between two atoms)
Hydrogen bond: (—–)
Strongest–>Covalent bond
ionic bond
Weakest –>Hydrogen bond

Question 14

Compare/contrast polar & nonpolar covalent bonds

Answer 14

-polar unequal sharing of electrons

Question 15

Define electronegativity and explain how it affects a covalent bond

Answer 15

-The attraction of an atom for electrons
-double covalent bond

Question 16

Know the unique properties of water

Answer 16

COHESION: H bonds hold molecule together
ICE IS LESS DENSE THAN WATER: ice float in lakes allow life to
continue below surface
HIGH SPECIFIC HEAT: absorbs large amount of energy b4
breaking H bonds–> will hold temp. well;
help moderate temp
HIGH HEAT OF VAPORAION: as water evaporates it takes
heat–> cooling effect
(sweating)
UNIVERSAL SOLVENT: polar & ionic substances dissolve in
water to form solutions

Question 17

dehydration synthesis vs. hydrolysis
What do these types of chemical reactions have to do with macromolecules?

Answer 17

Dehydration synthesis: removing water (@ end need energy)
Hydrolysis: Water breaking ( release energy)
-Used to make and break macromolecules

Question 18

Be able to identify the following functional groups: hydroxyl, amino, carboxyl, sulfhydryl, phosphate

Answer 18

Hydroxyl group: OH
Amino group: NH2
Carboxyl group: O-C-OH
Sulfhydryl group: S-H
Phosphate group: -P-

Question 19

What is a macromolecule?
o For the four macromolecules we studied

Answer 19

Carbohydrates, Lipids, Proteins, Nucleic Acids

Question 20

Carbohydrates:
 What is the subunit?
 What type of bond holds the subunits together?
 Where do you find it?
 What does it do?
 What elements make it up?

Answer 20

SUBUNIT: monosaccharide (disaccharide 2 monosaccharides,
polysaccharide)
BOND: glycosidic
FIND IT? : glucose, cellulose
WHAT DOES IT DO? : structural elements & energy storage
WHAT ELEMENTS MAKE IT UP: C H2 O

Question 21

Proteins:
 What is the subunit?
 What type of bond holds the subunits together?
 Where do you find it?
 What does it do?
 What elements make it up?

Answer 21

SUBUNIT: amino acids
BOND: peptide bonds (2° hydrogen bond)
FIND IT? : keratin & collagen
WHAT DOES IT DO? : Transport/ receptors/ enzymes/
structural/antibodies
WHAT ELEMENTS MAKE IT UP: C,H,O,N,P,S

Question 22

Lipids:
 What is the subunit?
 What type of bond holds the subunits together?
 Where do you find it?
 What does it do?
 What elements make it up?

Answer 22

SUBUNIT: fatty acids 1) triglycerides: 3 fatty acids joined to a
glycerol molecule
Oil-unsaturated double bonds C-kink
Fat- saturated sold butter
2) Phospholipids: 2 fatty acid +1
phosphate linked to glycerol forming
backbone (amphipathic: phobic one
end and phillic other end)
BOND: ester bond
FIND IT? : fats, oils, cholesterol
WHAT DOES IT DO?: messenger molecules( steroids)
energy reserve,
cell membrane (phospholipids)
WHAT ELEMENTS MAKE IT UP: C H O P
STERIODS: 4 rings structure
uses- hormones, light harvesting, maintain membrane fluidity
@ low temp.

Question 23

Nucleic acids:
 What is the subunit?
 What type of bond holds the subunits together?
 Where do you find it?
 What does it do?
 What elements make it up?

Answer 23

SUBUNIT: nucleotides
BOND: phosphodiester bond
FIND IT? : DNA & RNA
WHAT DOES IT DO? :genetic material, energy (ATP),
electron carriers(NAD, FAD)
WHAT ELEMENTS MAKE IT UP: C H O N P

Question 24

Why do phospholipids form membranes?

Answer 24

2 fatty acids monomers + 1 phosphate linked to a glycerol forming a backbone. They are amphipathic (hydrophobic-tail @ one end and hydrophilic @ other end) Micelle, bi-layer sheet, liposome (center hydrophilic-head)

Question 25

Describe the 4 levels of protein structure

Answer 25

1°: determine all higher levels of structure
-sequence of amino acids join by dehydration synthesis &
from peptide bonds
2°: hydrogen bond between members of peptide “backbone”
(carboxyl & amino group)
- R groups not involved
- alpha helix & beta sheet
3°: Hide hydrophobic amino acids from water
- 1 subunit
-shape is stabilized by bonds between R groups
-hydrogen bond(–), ionic (+/-),covalent (-), disulfide (s-s)
4°: functional structure
- 2 subunits
-shape is stabilized by bonds between R groups
-hydrogen bond(–), ionic (+/-),covalent (-), disulfide (s-s)

Question 26

Compare/contrast DNA and RNA
Recognize the structure of the nucleotide
Be able to tell me which end is 5’ and 3’
General functions of nucleotides/nucleic acids

Answer 26

-Monomer=nucleotides (DNA & RNA)
a. nitrogenous base
b. pentose sugar
c. phosphate
-two types of pentose sugar
1. Ribonucleotide in RNA (pentose has
hydroxyl group @ carbon 2 is Ribose)
2. Deoxyribonucleotide in DNA (just H+
no hydroxyl have deoxyribose b/c
removed)
DNA: deoxyribose + phosphate+ a base(adenine, guanine, cytosine, thymine-specific for DNA-)
-polymer is often double stranded &
twisted alpha helix
RNA: ribose+ phosphate+ a base (adenine, guanine, cytosine, uracil-specific for RNA-)
-polymer is most often a single strand
-3’ end OH
-5’ end P

Question 27

Define ion

Answer 27

an atom that has a full positive or negative charge