Test 2 Chemistry of Life Pt. 1 Final

Question 1

Covalent bonds

Answer 1

Bonds in which two atoms share electrons in order to fill or empty their outer shells of valence electrons

Question 2

Ionic bonds

Answer 2

Charged ions are electrostatically attracted to one another.
An Ionic bond is the bond formed by the complete transfer of valence electrons to attain stability in the outer shell of an atom
Many ionic compounds dissolve in water

Question 3

Hydrogen bonds

Answer 3

Attraction between a hydrogen atom with a partial positive charge and another atoms with a partial negative charge
Ex. hydrogen bonds bond water

Question 4

solutions

Answer 4

A solution is a type of mixture made of two or more things (at least one liquid) in which all components are evenly distributed (dissolved)

Question 5

mixture

Answer 5

a mixture made of two or more substances that are physically combined (mixed) together but not dissolved together (not chemically combined)

Question 6

suspension

Answer 6

heterogeneous mixture in which some of the particles settle out of the mixture upon standing.
Ex: flour and water mixture, chalk and water mixture.
Heterogeneous mixture that does not dissolve and the different parts will separate.
Mixture of water and nondissolved material

Question 7

pH scale

Answer 7

Hydrogen ion (H+1) is the basis of the pH scale.
Greater H+1 concentration = lower pH = Acidic
Lower H+1 concentration = higher pH = Basic
Ex. pure water is at middle of scale, concentration of H+ and H- ions is equal

Question 8

Acid

Answer 8

a chemical that releases H+1 ions
pH below 7

Question 9

base

Answer 9

a chemical that accepts and neutralize H+1 ions.
pH above 7

Question 10

polar vs. non polar

Answer 10

Polar molecules are hydrophilic, or “water loving”, attracted to water molecules and dissolve easily in water
Nonpolar molecules are hydrophobic, or “water fearing”, repelled by water molecules and do not dissolve in wate

Question 11

Capillary action

Answer 11

cohesion & adhesion working together to draw water up the veins of plants

Question 12

surface tension

Answer 12

a measure of the force necessary to stretch or break the surface of a liquid, is related to cohesion.

Question 13

“Like dissolves like”

Answer 13

Polar substances dissolve well in other polar substances.
Nonpolar substances dissolve well only in other nonpolar substances

Question 14

Elements in Carbs, lipids, amino acids, and nucleic acids (look at their structures on doc, try to memorize)

Answer 14

Carb - C, H, O
Lipid - C, H, O
Amino acid - C, H, O, N, S
Nucleic acid - N, H, O, P, C

Question 15

Characteristics of lipids

Answer 15

Made of mostly carbon & hydrogen
Can be used to store energy
LONG chains of CH2
Renders molecule nonpolar and thus insoluble in water

Question 16

lipids Types and uses

Answer 16

Fats
long-term energy storage and thermal insulation in animals
Ex. butter, lard

Oils
long term energy storage in plants and their seeds
Ex. cooking oils

Phospholipids
Part of cell membrane
Ex. non stick spray

Steroids
Part of cell membrane, hormones
Ex. medicines

Waxes
Water resistance, water retention
Waxes, candles

Question 17

lipids structure

Answer 17

(Except for steroids) Usually contain a glycerol with fatty acids attached.

Question 18

why doesn’t oil mix with water?

Answer 18

water is polar and oil is non polar

Question 19

triglycerides

Answer 19

Fats
Long-term energy storage
Backbone of one glycerol molecule
( 3-C alcohol with 3 OH- groups)
Three fatty acids attached to each glycerol molecule
F.A. = long hydrocarbon chain
Carboxylic acid (COOH) at one end
COOH connects to –OH on glycerol in dehydration synthesis

Question 20

saturated vs unsaturated

Answer 20

Saturated - no double bonds between C’s
Unsaturated - ≥1 double bonds between C’s
Unsaturated fatty acids (ex. olive oil) tend to be liquid at room temp

Question 21

trans fats vs. cis fats

Answer 21

Trans - The hydrogens connecting to the carbons are on different sides
Cis - The hydrogens connecting to the carbons are on the same side

Question 22

Steroids

Answer 22

Cholesterol, hormones, vitamins

Question 23

Phospholipids

Answer 23

In a phospholipid, two fatty acids and a phosphate group are attached to glycerol
The two fatty acid tails are hydrophobic, but the phosphate group and its attachments form a hydrophilic head
Phospholipids are major consituents of cell membranes

Question 24

Phospholipid bilayer

Answer 24

when phospholipids are added to water, they self assemble into a bilayer, with the hydrophobic tails pointing toward the interior
this feature of phospholipids results in the bilayer arrangement found in cell membranes
the phospholipid bilayer forms a boundary between a cell and its external environment

Question 25

Dehydration synthesis

Answer 25

occurs when two molecules or compounds are joined to form a larger molecule following the removal of water.

Question 26

hydrolysis

Answer 26

Hydrolysis is any chemical reaction in which a molecule of water breaks one or more chemical bonds
Adding a water molecule to break apart

Question 27

Amphipathic

Answer 27

a chemical compound containing both polar (water-soluble) and nonpolar (not water-soluble) portions in its structure.
phospholipids are amphipathic

Question 28

Carbs def

Answer 28

Made up of carbon, hydrogen, and oxygen
1:2:1 ratio of C:H:O

Question 29

Uses/General purposes carbs IMPORTANT

Answer 29

Short term / transportable energy storage
Ex: lactose, a sugar in milk

Longer-term energy storage
Ex: starch (plant-based) and glycogen (in muscles)

Structure
Ex: cellulose (in cell walls of plant cells)
chitin (forms cell walls of fungi and the exoskeletons of many invertebrates

Question 30

ex. of carbs

Answer 30

a. Sugars – anything ending in “-ose”
Sucrose, glucose, fructose, lactose
Cellulose – strong support that makes up plant walls (ingestible so it forms fiber in your diet)

b. Starch – a long chain of sugars joined together, such as in in pasta, cereals, breads, potatoes, etc.

Question 31

types of carbs

Answer 31

Carbs can be polymers of monomers
Simple sugar monomers are called monosaccharides
Ex: glucose, fructose, ribose
b. Two monosaccharides can join to form a disaccharide
Ex: sucrose, lactose, maltose
d. Polysaccharides: long chains of connected monosaccharides
Ex: starch, glycogen, cellulose, chitin

Question 32

formation of di- and polysaccharide

Answer 32

dehydration synthesis - loss of water (H2O) in joining 2 molecules together

Question 33

Be able to recognize a carbohydrate when given a structural drawing or molecular formula.

Answer 33

1:2:1 ratio of CHO