Bio-168 Ch. 2

Front 1

What are the subatomic structures that make up an atom?

Back 1

Protons (P+)

Neutrons (N)

Electrons (E-)

Front 2

Complete atoms have the same # of what particles?

Back 2

Protons (P+) & Electrons (E-)

Front 3

The number of protons in the atoms of a particular element:

Back 3

Atomic number

Front 4

The number of protons + the number of neutrons in the atoms of a particular element:

Back 4

Atomic weight

Front 5

All atoms of a particular element have the same atomic _______.

Back 5

Number

Front 6

The atoms of an element vary in the number of _________ in their nuclei; thus they vary in atomic _________.

Back 6

Neutrons;

Weight

Front 7

Atoms of an element with different atomic weights:

Back 7

Isotopes

Front 8

Unstable isotopes are called _______ because they emit energetic particles, and the energy or atomic fragments they give off are called _______.

Back 8

Radioactive;

Radiation

Front 9

Elements are determined and identified by what?

Back 9

The number of protons in the nucleus (atomic number)

Front 10

The time required for an isotope to lose one-half of its radioactivity:

Back 10

Half-life

Front 11

The chemical behavior of atoms results from interactions among their _______.

Back 11

Electrons

Front 12

When atoms form chemical bonds, they gain, lose, or share _______.

Back 12

Electrons

Front 13

The electrons of an atom occupy one or more areas of space, called _______, around the nucleus.

Back 13

Shells

Front 14

Max. # of electrons that the first three inner shells can hold:

Back 14

First shell: 2

Second shell: 8

Third shell: 8

Front 15

Atoms whose outermost shells are filled, have stable structures & are chem. inactive are called ______.

Back 15

Inert

Front 16

Atoms that gain or lose electrons, becoming electrically charged:

Back 16

Ions

Front 17

Atoms that gain electrons become _______.

Back 17

Negative ions

Front 18

Atoms that lose electrons become _______.

Back 18

Positive ions

Front 19

Ionic bonds:

Back 19

Formed between oppositely charged ions in close proximity.

Front 20

Covalent bonds:

Back 20

Formed between atoms that share electrons

Front 21

What happens when covalent bonds are broken?

Back 21

Energy is released

Front 22

Polar covalent bond:

Back 22

Electrons are shared, but not equally, such that they move toward one of the bonded atoms

Front 23

When do polar covalent bonds typically form?

Back 23

When hydrogen atoms bond to oxygen or nitrogen atoms

Front 24

Polar molecule:

Back 24

Has an equal number of protons & electrons, but more of the electrons are at one end of the molecule, making that end slightly negative, while the other end is slightly positive.

Front 25

Why is water called the "universal solvent"?

Back 25

It has the ability to break ionic bonds, due to its polar nature.

Front 26

Hydrogen bond:

Back 26

The attraction of the positive (H) end of a polar molecule to the negative (O or N) end of another polar molecule.

Front 27

When water (H2O) breaks apart, it forms _____ & _____.

Back 27

Hydrogen ions (H+) & hydroxide ions (OH-)

Front 28

What does pH stand for?

Back 28

Percentage of hydrogens

Front 29

What does pH measure?

Back 29

Hydrogen ion concentration

Front 30

A solution is _______ if there are more hydrogen (H+) ions than hydroxide (OH-) ions.

Back 30

Acidic

Front 31

A solution is _______ if there are more hydroxide (OH-) ions than hydrogen (H+) ions.

Back 31

Basic (Alkaline)

Front 32

A solution is _______ if it has equal numbers of hydrogen (H+) & hydroxide (OH-) ions.

Back 32

Neutral

Front 33

A neutral solution has a pH _______ 7.

Back 33

equal to

Front 34

An acidic solution has a pH ________ 7.

Back 34

less than

Front 35

A basic, or alkaline, solution has a pH _______ 7.

Back 35

greater than

Front 36

What does each whole number on the pH scale represent?

Back 36

A tenfold difference in hydrogen (H+) ion concentration.

Front 37

Substances that release ions in water:

Back 37

Electrolytes

Front 38

Electrolytes that release hydrogen (H+) ions in water:

Back 38

Acids

Front 39

Electrolytes that release ions that bond with hydrogen (H+) ions:

Back 39

Bases

Front 40

Chemicals that resist pH change:

Back 40

Buffers

Front 41

How do buffers resist pH change?

Back 41

They combine with hydrogen (H+) ions when those ions are in excess & donate hydrogen (H+) ions when those ions are depleted.

Front 42

Organic molecules always contain what two elements?

Back 42

Carbon & hydrogen

Front 43

A molecule made up of C, H, & O, where there are twice as many H's as O's, and usually twice as many H's as C's:

Back 43

Carbohydrates

Front 44

What is a monosaccharide?

Back 44

A carbohydrate with one C-backbone

Front 45

What is a disaccharide?

Back 45

A carbohydrate with two C-backbones

Front 46

What is a polysaccharide?

Back 46

A carbohydrate with three or more C-backbones

(complex carbohydrate)

Front 47

Why are carbohydrates soluble in water?

Back 47

Water forms H-bonds to the polar areas of the molecule, dissolving it.

Front 48

What is the structure of a triglyceride?

Back 48

A glycerol molecule + three fatty acid chains

Front 49

What is the structure of a phospholipid?

Back 49

A triglyceride molecule + two fatty acid chains & a phosphate group

Front 50

What makes a fat saturated?

Back 50

All C-atoms are linked by single bonds, so they bind as many H-atoms as possible

Front 51

What makes a fat unsaturated?

Back 51

There are one or more double bonds between the C-atoms

Front 52

What is the structure of an amino acid molecule?

Back 52

A central carbon bonded to a hydrogen, with an amino group (-NH2) at one end, a carboxyl group (-COOH) at the other end, and an R-group across from the H

Front 53

What are proteins made up of?

Back 53

Chains of amino acids

Front 54

How many different types of amino acids are there?

Back 54

20

Front 55

What is the primary structure of a protein?

Back 55

The specific amino acid sequence of the polypeptide chain

Front 56

What is the secondary structure of a protein?

Back 56

The coiling or pleating of the polypeptide chain arising from H-bonding between the O- & H-atoms in different parts of the chain

Front 57

What is the tertiary structure of a protein?

Back 57

Major bending, folding, & coiling (due to H- & covalent boding of R-groups) which produces an active site

Front 58

What is the quaternary structure of a protein?

Back 58

Two ro more proteins combined to form a larger molecule

Front 59

What are the building blocks of nucleic acids?

Back 59

Nucleotides

Front 60

What is the structure of a nucleotide?

Back 60

A five-C sugar (ribose or deoxyribose), with a phosphate group & a nitrogenous base attached

Front 61

What are the five nitrogenous bases found in DNA & RNA?

Back 61

1. Adenine (both)

2. Thymine (DNA)

3. Guanine (both)

4. Cytosine (both)

5. Uracil (RNA)

Front 62

What is the structure of ATP?

Back 62

Adenosine triphosphate:

adenine + ribose + 3 phosphates

Front 63

What sugars are used in DNA & RNA?

Back 63

DNA: deoxyribose

RNA: ribose

Front 64

Where is the bond found between two nucleotides in a polynucleotide?

Back 64

Between the sugar of one nucleotide & the phosphate of the next