Chap 2 Chemistry of Life Flashcards
(112 cards)
1
Q
What is matter?
A
any material that takes up space
2
Q
What is an element?
A
a substance that cannot be broken down by chemical means into other substances
3
Q
What does the atomic number represent?
A
number of protons
4
Q
What does the atomic weight (mass) represent?
A
number of protons and neutrons (avg)
5
Q
What is an atom?
A
the smallest piece of an element that retains the characteristics of the element
6
Q
List the three subatomic particles
A
Protons
Neutrons
Electrons
7
Q
Where are the subatomic particles found?
A
Electrons - surrounding the nucleus
Protons and Neutrons - close together in the nucleus
8
Q
What are the charges on the subatomic particles?
A
Electron - negative (-)
Neutron - none
Proton - Positive (+)
9
Q
What are Ions?
A
When an atom either gains or loses electrons
10
Q
What are Isotopes?
A
the number of neutrons vary among atoms of the same element
11
Q
What are molecules?
A
two or more chemically joined atoms
12
Q
What are compounds?
A
molecules of two or more elements
13
Q
What determines chemical bonding?
A
electrons
14
Q
In what way do electrons exist?
A
in energy shells/orbitals
15
Q
When are atoms stablest?
A
when their outer shell has no vacancies
16
Q
How do atoms fill vacancies in their outer shells?
A
bonding with other atoms
17
Q
What is a Covalent bond?
A
electrons are shared
18
Q
What is Electronegativity?
A
measure of an atom’s ability to attract electrons
19
Q
Valency when looking at periodic table
A
Rows - number of energy shells
Columns - number of electrons
20
Q
What determines the type of chemical bond formed?
A
electronegativity differences
21
Q
Atoms with similar electronegativity form what kind of bonds?
A
nonpolar covalent
22
Q
Atoms with some different electronegativity form what kind of bonds?
A
polar covalent
23
Q
Atoms with very different electronegativity form what kind of bonds?
A
ionic
24
Q
What is an Ionic bond?
A
a transfer of electrons
25
What creates an ionic bond?
the attraction between oppositely charged ions
26
Can some atoms be partially charged?
yes
27
What is a Hydrogen bond?
when an atom has a partial charge
28
What gives water its emergent properties?
hydrogen bonds
29
What is essential to life?
water
30
Unique properties of water
```
cohesive
adhesive
excellent solvent
dissolves salt
regulates temperature
expands when frozen
participates in chem rxns
```
31
What is cohesion?
tendency of water molecules to stick to one another
32
What creates surface tension on water?
cohesion
33
What is adhesion?
water molecules form hydrogen bonds with other molecules.
34
What can water dissolve?
Hydrophilic substances - Polar solutes, ions
35
What helps water dissolve most biologically important molecules?
its polarity
36
How does salt dissolve in water?
Neg charge (O) attracts positive (Na)
Pos charge (H) attracts negative (Cl)
37
Hydrogen bonds in water make it resist what?
temperature changes (cools and heats very slowly)
38
What happens when water freezes?
it expands and becomes less dense
39
What is a chemical reaction?
when two or more molecules (reactants) exchange their atoms resulting in different molecules (products)
40
What are life's chemical reactions?
Photosynthesis
| Respiration
41
What is the pH scale based on?
the amount of H+ in a solution
42
What pH do most chem rxns in a cell occur?
pH = 7
43
pH and H+ of acidic solution
pH = low
| H+ - high
44
pH and H+ of basic solution
```
pH = high
H+ = low
OH- = higher than H+
```
45
What happens if an organism strays too far from its optimal pH?
it could die
46
What is the homeostasis pH of many organisms?
pH = 7
47
What does a Buffer Solution?
when pH is too high releasees H+ ion to lower pH
when pH is too low absorbs H+ ions to raise the pH
48
What is an organic molecule?
a molecule containing both carbon and hydrogen
49
What are the four categorized organic molecules needed for life's processes?
Carbohydrates
Proteins
Nucleic acids
Lipids
50
What are organic molecules made up of?
functional groups
| monomers
51
List the four functional groups
Hydroxyl -OH
Carboxyl -COOH
Amino -NH(2)
Phosphate -PO(4)^-2
52
What are monomers?
a single unit of a carbohydrate, protein, or nucleic acid
53
Monomers join to form what?
polymers
54
What joins monomers together
dehydration synthesis
55
During dehydration synthesis what happens with water?
a water molecule is released
56
What happens in dehydration synthesis?
enzymes form bonds between two monomers
57
What breaks polymers apart?
Hydrolysis
58
What happens in hydrolysis?
enzymes break bonds between monomers
59
During hydrolysis what happens with water?
a water molecule is needed for the rxn to occur
60
What do carbohydrates include?
simple sugars
| polysaccharides
61
What are monosaccharides?
simple sugars; they are the monomers that make up carbohydrates
62
Examples of monosaccharides?
ribose, glucose, fructose
63
How are carbohydrates synthesized?
Dehydration synthesis (bonds two monosaccharides together forming a disaccharide) e.g. sucrose
64
How are carbohydrates broken down?
Hydrolysis (separates disaccharides into monosaccharides)
65
What are polysaccharides?
long chains of carbohydrates
66
Examples of polysaccharides
cellulose: structure
starch: energy
glycogen: energy
67
Proteins have many different what?
structures and functions
68
What are proteins?
the workers of the cells; they do almost everything
69
What are proteins made of?
amino acids
70
What are the monomers of protein?
amino acids
71
What is the general animo acid structure?
look up slide 32 of lecture 4
72
How many different amino acids are there in nature?
20
73
What determines the properties of a protein?
the properties of the amino acids (each has its own R-group)
74
How are Proteins synthesized?
dehydration synthesis (binds two amino acids together forming a dipeptide)
75
What is a long chain of amino acids called?
polypeptide
76
What breaks down proteins?
hydrolysis (separates dipeptides and polypeptides into individual amino acids)
77
How do polypeptides form proteins?
they fold up
78
Denatured proteins lose what?
their shape
79
The function of a protein depends on what?
shape or tertiary structure
80
Primary structure of proteins
amino acid sequence of polypeptides
81
Secondary structure of proteins
localized areas of coils, sheets, and loops within a polypeptide
82
Tertiary structure of proteins
overall shape of one protein
83
Quaternary structure of proteins
overall protein shape; arises from the interaction b/w the multiple polypeptides that make up the functional protein
84
What do nucleic acids do?
carry genetic information
85
Give examples of nucleic acids
DNA
| RNA
86
The primary structure of each protein in a cell is determined by?
the nucleic acids
87
What are the monomers of nucleic acids?
nucleotides
88
What are the three parts of a nucleotide?
phosphate group
five-carbon sugar
nitrogenous base
89
How many different possible nitrogenous bases are there?
5
90
List the 5 nucleotides
```
Adenine (A)
Cytosine (C)
Guanine (G)
Thymine (T)
Uracil (U)
```
91
Which nitrogenous base does only DNA use?
Thymine (T)
92
Which nitrogenous base does only RNA use?
Uracil (U)
93
Which nitrogenous bases does both DNA and RNA use?
Adenine (A)
Cytosine (C)
Guanine (G)
94
How are nucleic acids synthesized?
dehydration synthesis (binds two nucleotides together forming a dipeptide)
95
How are nucleic acids broken down?
hydrolysis
96
Characteristics of DNA
double helix
Nitrogenous baes held together by hydrogen bonds (A to T, G to C)
Function: store genetic info
97
Characteristics of RNA
single stranded
nitrogenous bases: A to U, G to C
Function: caries DNA information to protein-synthesizing organelles
98
Are lipids built from chains of monomers?
No
99
Are lipids hydrophobic or hydrophilic?
hydrophobic
100
Classes of lipid
Triglycerides
| Steroids
101
What are triglycerides?
fats and oils
energy rich
for long term energy storage
102
What are steroids?
have four ring structure
103
How are Triglycerides formed?
by covalently attaching three fatty acid molecules to a glycerol molecule
104
What links fatty acids to the glycerol?
dehydration synthesis
105
How are triglycerides broken down?
hydrolysis
106
What are saturated fatty acids?
all carbons are bonded to four other atoms. gives it a straight shape
107
What are unsaturated fatty acids?
contains at least one double bond. gives it a bent shape (prevents them from packing close together)
108
At room temp what are saturated fatty acids?
solid
109
At room temp what are unsaturated fatty acids
liquid
110
At room temp what are trans fats?
solid
111
Cholesterol is what?
a lipid in the steroid class
112
What does cholesterol do?
regulates the fluidity of animal cell membranes
also used to synthesize many sex hormones
