Exam 2

Question 1

Acids

Answer 1

when dissolved in h2o, releases H ions

Question 2

Bases

Answer 2

acceptors of those H ions

Question 3

Functional group of biological acids

Answer 3

carboxylic acid

Question 4

pH scale is based on…

Answer 4

the concentration of hydrogen ions (H+) in a solution and how acidic/basic water is, and the negative log of the molar
concentration of H+ ions:

Question 5

pH of acid

Answer 5

Lower pH number = higher [H+] =
greater acidity, #1-6

Question 6

pH of base

Answer 6

Higher pH number, #8-16

Question 7

pH of neutralization

Answer 7

pH = 7, neither too acidic nor basic

Question 8

Buffers

Answer 8

a weak acid and its corresponding base; helps maintain constant pH

Question 9

Importance of buffers

Answer 9

Important for preventing pH changes that could disrupt ability of blood to carry oxygen to tissues

Question 10

Law of mass action

Answer 10

addition of a reactant on one side of a reversible system drives the system in the direction that uses up that compound

Question 11

Isomers and different types

Answer 11

molecules with the same chemical formula but atoms are arranged in different ways. Types include structural, cis-trans, and optical

Question 12

Structural isomers

Answer 12

differ in how atoms are joined together

Question 13

Cis-trans isomers

Answer 13

different orientation around a double bond

Question 14

Optical isomers

Answer 14

occur when C atom has four different groups attached to it (an asymmetric carbon)

Question 15

4 functional groups discussed

Answer 15

Hydroxyl, carboxyl, amino, and phosphate

Question 16

Hydroxyl

Answer 16

R-OH, forms hydrogen bonds with water to help dissolve molecules, enables linkage to other molecules by condensation

Question 17

Carboxyl

Answer 17

R-O=C-OH, charged, acidic, ionizes in living tissues to form COOH- and H+, some are important in energy releasing reactions

Question 18

Amino

Answer 18

R-N-H-H, charged, basic, accepts H ions in living tissues to form NH3+, enters into condensation reactions by giving up H+

Question 19

Phosphate

Answer 19

R-O-P=O-O(-)-Cl(-), charged, acidic, enters into condensation reactions by giving up OH, when bonded to another phosphate, hydrolysis releases a lot of energy

Question 20

Organic compounds and what they consist of

Answer 20

any of a large class of chemical compounds in which one or more atoms of carbon are covalently linked to atoms of other elements, most commonly hydrogen, oxygen, or nitrogen

Question 21

4 major types of organic compounds

Answer 21

proteins, carbs, lipids, and nucleic acids

Question 22

Hydrolysis

Answer 22

break down polymers into monomers ‐ energy released, H2O consumed

Question 23

Condensation reactions

Answer 23

form polymers ‐ energy required and H20 molecule removed, ex: dehydration synthesis

Question 24

Spontaneous generation

Answer 24

creating life from inanimate objects/nature

Question 25

Redi experiment

Answer 25

disproved of spontaneous generation by placing meat in open jars to demonstrate that dead maggots or flies would not generate new flies when placed on rotting meat in a sealed jar, whereas live maggots or flies would

Question 26

Pasteur experiment

Answer 26

In 1858, Pasteur filtered air through a gun-cotton filter and, upon microscopic examination of the cotton, found it full of microorganisms, suggesting that the exposure of a broth to air was not introducing a “life force” to the broth but rather airborne microorganisms.

Question 27

Life from outside Earth

Answer 27

Some meteorites contain molecules such as purines, pyrimidines, and amino acids, suggests that living organisms may have reached Earth via meteorite. meteorite was discovered in Australia in 1969, analyzed water: amino acids, nucleotide bases, and sugars found

Question 27

Chemical evolution

Answer 27

1st theory on how life arose, conditions on primitive Earth led to formation of simple molecules, which led to formation of life
forms

Question 28

Miller Urey experiment

Answer 28

a scientific experiment conducted in 1952 that simulated the conditions of early Earth’s atmosphere, demonstrating that organic molecules, like amino acids, could be formed from simple inorganic compounds through chemical reactions

Question 29

Key to the origin of life

Answer 29

catalysts - proteins called enzymes that speed up reactions

Question 30

Ribozyme

Answer 30

catalytic RNAs that speed up reactions involving their own nucleotides

Question 31

what came first – DNA, RNA, or protein

Answer 31

possible that RNA was the first catalyst since its molecules are similar to enzymes, RNA could have acted as a catalyst for its own replication and synthesis of proteins, DNA could have then evolved from RNA

Question 32

Protocell

Answer 32

steppingstones for origins of cells, are organized systems of parts w/ substances interacting, sometimes catalytically, have interior distinct from exterior environment, can self‐replicate

Question 33

Cell theory

Answer 33

an important unifying theory of biology

Question 34

Cell theory states that

Answer 34

• Cells are the fundamental units of life.
• All organisms are composed of cells.
• All cells come from preexisting cells.
• Modern cells evolved from a common ancestor

Question 35

Cell theory implications

Answer 35

• Functions of all cells are similar
• Life is continuous
• Origin of life was origin of cells

Question 36

Size of a prokaryotic cell

Answer 36

0.1 to 5.0 micrometers (μm) in diameter

Question 37

Size of a eukaryotic cell

Answer 37

10 to 100 μm

Question 38

Passive transport

Answer 38

no energy input required, with concentration gradient

Question 39

Active transport

Answer 39

energy and transport protein required, against concentration gradient

Question 40

What factors affect the rate of diffusion

Answer 40

• Size and mass of molecules or ions
• Temperature of the solution
• Density of the solution
• Concentration gradient
• Area and distance across which substance diffuses

Question 41

Osmosis

Answer 41

diffusion of water, depends on relative concentrations of water molecule

Question 42

Isotonic

Answer 42

equal solute concentrations

Question 43

Hypotonic

Answer 43

low solute concentration, lot of water in cell

Question 44

Hypertonic

Answer 44

high solute concentration, little water in cell

Question 45

Turgor pressure

Answer 45

plant cells with rigid cell walls build up internal pressure that keeps more water from entering

Question 46

3 proteins in active transport

Answer 46

• Uniporter: moves one substance in one direction
• Symporter: moves two substances in one direction
• Antiporter: moves two substances in opposite directions

Question 47

Primary vs. Secondary active transport

Answer 47

Primary active transport requires direct hydrolysis of ATP, Secondary active transport energy comes from ion
concentration gradient established by primary active transport

Question 48

Endocytosis vs. Exocytosis

Answer 48

Endocytosis - brings molecules and cells into a eukaryotic cell, bigger molecules need vesicles to get in
Exocytosis - materials in vesicles expelled from cell

Question 49

Phagocytosis vs. pinocytosis vs. receptor-mediated endocytosis

Answer 49

Phagocytosis: molecules or entire cells are engulfed
Pinocytosis: vesicle forms to bring small, dissolved substances or
fluids into a cell
Receptor-mediated endocytosis - very specific; macromolecules bind to receptor proteins