Chapter 2 - The Chemistry of Life Flashcards
0
Q
Which 6 elements account for 98.5% of body’s weight?
A
O- Oxygen C- Carbon H- Hydrogen N- Nitrogen Ca- Calcium P- Phosphorus
1
Q
What is a chemical element?
A
The simplest form of matter to have unique chemical properties
2
Q
Which 6 elements account or 0.8% of body’s weight?
A
S- Sulfur K- Potassium Na- Sodium Cl- Chlorine Mg- Magnesium Fe- Iron
3
Q
What are the remaining trace elements (12)?
A
Cr- Chromium Co- Cobalt Cu- Copper F- Fluorine I- Iodine Mn- Manganese Mo- Molybdenum Si- Silicon Sn- Tin V- Vanadium Zn- Zinc
4
Q
What are minerals?
A
Inorganic elements extracted from the soil of plants
5
Q
Particle so small that nothing can cut it?
A
Atom
6
Q
The nucleus of an atom is composed of?
A
Protons and neutrons
7
Q
Has a single positive charge
A
Proton
8
Q
Has no charge
A
Neutron
9
Q
Has a single negative charge
A
Electron
10
Q
Around the nucleus are?
A
One or more concentric clouds of electrons
11
Q
Electrons determine?
A
The chemical properties of an atom
12
Q
The number of electrons equals?
A
The number of protons
13
Q
What determines the bonding of an atom?
A
The electrons in the outermost shell when electrons swarm the nucleus in electron shells (energy levels)
14
Q
What is an isotope?
A
Elements which differ in number of neutrons
15
Q
What are radioisotopes?
A
Isotopes that are unstable and decay (breakdown) to more stable isotopes by giving off radiation
16
Q
What is ionizing radiation?
A
High-energy radiation that destroys molecules and produces dangerous free radicals and ions in human tissues
17
Q
What are ions?
A
Charged particles with unequal numbers of protons and electrons
18
Q
Elements with 1-3 electrons in their outer shell tend to do what?
A
Give up electrons
19
Q
Elements with 4-7 electrons in their outer shell tend to do what?
A
Gain more electrons
20
Q
What are anions?
A
Particles that gain electrons and acquire a negative charge
21
Q
What are cations?
A
Particles that lose electrons and acquire a positive charge
22
Q
Ions with opposite charges are?
A
Attracted to each other and tend to follow each other through the body
23
Q
What are electrolytes?
A
Compounds that ionize in water and form solutions capable of conducting electricity
24
What are electrolytes important for?
Their chemical reactivity, osmotic effects, and electrical effects
25
What are free radicals?
Chemical particles with an odd number of electrons
26
How are free radicals produced?
By normal metabolic reactions and combine with molecules which converts them into free radicals
27
What are chemical bonds?
Forces that hold a molecule together and attract molecules to one another
28
What are the different types of chemical bonds?
Ionic bonds
Covalent bonds
Hydrogen bonds
Van der Waals forces
29
What is an ionic bond?
A weak attraction of a cation to an anion that easily dissociates in the presence of something more attractive
30
What is a covalent bond?
An attraction between atoms formed by the sharing of electrons
31
What are the different types of covalent bonds?
Single Covalent Bond- sharing of a single pair of electrons.
| Double Covalent Bond- sharing of two pairs of electrons.
32
What is a hydrogen bond?
A weak attraction between hydrogen atom in a molecule and an oxygen or nitrogen in another
33
What are Van der Waals forces?
Weak, brief attractions between neutral atoms
34
Most mixtures in our bodies are chemicals dissolved or suspended in?
H2O
35
What is solvency?
The ability to dissolve other chemicals
36
What are the types of solvency?
Hydrophilic- substances that dissolve in water.
| Hydrophobic- substances that do not dissolve in water.
37
What is adhesion?
The tendency of one substance to cling to another
38
What is cohesion?
The tendency of molecules of the same substance to cling to each other
39
What is surface tension?
A force that holds water molecules together so that they form an elastic layer
40
What happens during chemical reactivity?
Water participates in chemical reactions by ionizing other chemicals
41
What happens during thermal stability?
Water has a high heat capacity and thus can absorb heat without changing temperature much
42
What is a solution?
Particles (solute) under 1 nm mixed with a liquid (solvent).
43
Identities of a solution
a) Particles will pass through most selectively permeable membrane.
b) Solution does not separate when allowed to stand.
44
What is a colloid?
Particles 1 to 100 nm mixed with a liquid
45
Identity of a colloid
Particles this large scatter light, so colloids are usually cloudy
46
What is suspension?
Particles larger than 100 nm mixed with a liquid
47
Identities of a suspension
a) Particles will not pass through membranes.
| b) Particles separate from liquid on standing.
48
What are the Measures of Concentration of Solutions?
Weight per volume
Percentages
Molarity
49
What is an acid?
A proton (H+) donor
50
What is a base?
A proton acceptor or OH- donor
51
What is pH?
A measure derived from the molarity of H+ (ph= -log [H+])
52
A pH of 7.0 is?
Neutral solution
53
A pH of below 7.0 is?
Acidic solution
54
A pH of above 7.0 is?
Basic (alkaline) solution
55
What is energy?
The capacity to do work
56
What are the different types of energy?
a) Potential Energy- energy contained in an object because of its position or internal state but it is not doing work at the time.
b) Kinetic Energy- energy of motion, energy that is doing work.
57
What is chemical energy?
Potential energy stored in the bonds of molecules
58
What is a chemical reaction?
A process in which a bond is formed or broken
59
What is a decomposition reaction?
When a large molecule breaks down into smaller ones
60
What are the different types of Reactions?
Chemical Reaction
Decomposition Reaction
Synthesis Reaction
Exchange Reaction
61
What is a synthesis reaction?
When small molecules combine to form a larger one
62
What is an exchange reaction?
When two molecules exchange atoms or groups of atoms
63
Metabolism
All chemical reactions in the body
64
Catabolism
Energy-releasing decomposition reactions
65
Anabolism
Energy-storing synthesis reactions that require energy input
66
What is carbon?
A versatile atom that serves as basis of a variety of structures.
a) Has 4 valence electrons.
b) Can bond with other carbon to form long chains, branched molecules and rings.
c) Commonly bonds with H, O, N, and S.
67
What are functional groups?
Small clusters of atoms, attached to a carbon backbone, which determine the properties of an organic molecule
68
Different types of functional groups?
```
Hydroxyl - OH
Methyl - CH3
Carboxyl - COOH
Amino - NH2
Phosphate - H2PO4
```
69
What are monomers?
Subunits
70
What are polymers?
Molecules made of a repetitive series of identical or similar subunits
71
What is dehydration synthesis?
-OH group is removed from from a monomer and a -H from another, producing H2O and forming covalent bond between them
72
What is hydrolysis?
When water ionizes to OH- and H+, covalent bond is broken between monomers with OH- added to one monomer and H+ added to another
73
What is a carbohydrate?
A hydrophilic organic molecule with the general formula (CH2O)n, where n represents the number of carbon atoms
74
Three primary types of carbohydrates?
Glucose
Fructose
Galactose
75
What is glucose?
The "blood sugar" that provides energy for most cells
76
What are disaccharides?
Sugars composed of two monosaccharides, important ones are sucrose, lactose, and maltose
77
What are oligosaccharides?
Short chains of three or more monosaccharides
78
What are polysaccharides?
Long chains of monosaccharides
79
Different types of polysaccharides?
a) Glycogen - energy-storage molecule made by cells of the liver, muscles, brain, uterus, and vagina.
b) Starch - energy-storage molecule of plants that is digestible by humans.
c) Cellulose - molecule that gives strength to the cell walls of plants, not digestible by humans but is important as dietary fiber.
80
What are the functions of carbohydrates?
a) A source of energy that can be quickly mobilized.
b) Carbs. are converted to glucose, which is oxidized to make ATP.
c) Glycolipids
d) Glycoproteins
e) Proteoglycans
81
Function of glycolipids?
Component of cell surface coat
82
Function of glycoproteins?
Component of cell surface coat and mucus
83
Function of proteoglycans?
Cell adhesion, lubrication, and filler of some tissues
84
What is a lipids?
A hydrophobic organic molecule with a high ratio of H to O
85
What is a fatty acid?
A chain of carbon atoms with a -COOH at one end and -CH3 on the other
86
What are different types of fatty acids?
a) Saturated Fatty Acid - has as much hydrogen as it can hold.
b) Unsaturated Fatty Acid - contains some double bonds so hydrogen could be added to the molecule.
87
What is a triglyceride?
A molecule consisting of three fatty acids bonded to glycerol
88
What are different types of triglycerides?
a) Oils - triglycerides that are liquid at room temperature.
b) Saturated Fats - triglycerides that are solid at room or body temperature.
c) Adipose Tissue - used for energy storage, insulation and cushions organs.
89
What are phospholipids?
A molecule consisting of three fatty acids and one fatty acid is replaced by a phosphate group
90
Identities of phospholipids
a) The fatty acids are hydrophobic, but the phosphate is hydrophilic.
b) Phospholipids serve as the foundation of cell membranes.
91
What are eicosanoids?
20-carbon compounds derived from a fatty acid
92
Identity of eicosanoids
Function as hormone-like chemical signals between cells
93
What is are the functions of prostaglandins?
They a variety of signaling roles in inflammation, blood clotting, hormone action, labor contractions, etc.
94
What is cholesterol?
A lipid with carbons arranged in four rings.
a) The "parent" from which steroids are formed.
b) A component of cell membranes and is required for nervous system functions.
95
What is protein?
A polymer of amino acids.
a) A polypeptide of 50 amino acids or more.
b) Have complex structures where a change in their conformation can destroy the function.
96
What is an amino acid?
An amino acid has a central carbon atom with an amino group, a carboxyl group and a functional or radical group
97
What is a peptide?
A molecule composed of two or more amino acids with an amino group bound to a carboxyl group of the next
98
What is an oligopeptide?
A chain of fewer than 15 amino acids
99
What is a polypeptide?
A chain of more than 15 amino acids
100
What is the primary structure of protein?
The protein's sequence of amino acids, which is encoded in the genes
101
What is the secondary structure of protein?
Coiled or folded shape held together by H bonds between C=O group and N-H group some distance away
102
What is the tertiary structure of protein?
Further bending and folding of proteins unto various globular and fibrous shapes
103
What is the quaternary structure of protein?
Association of two or more polypeptide chains by non-covalent forces
104
What is an important property of protein?
Their ability to change conformation
105
What are the functions of protein?
```
Structure
Communication
Membrane transport
Catalysis
Recognition and protection
Movement
Cell adhesion
Enzymes
```
106
What do enzymes do?
a) Enable reactions to occur rapidly at normal body temperatures.
b) Lower the activation energy and release energy in small steps
107
Enzyme action
a) A substrate molecule approaches the active site of the enzyme.
b) The substrate binds to the enzyme to form a complex.
c) The enzyme breaks bonds between 2 molecules or brings 2 molecules together and makes them react with each other.
d) The products are released.
108
What happens if there is a change in shape in an enzyme?
Change in shape in an enzyme alters or destroys its ability to bind to its substrate
109
What is a cofactor?
Nonprotein partner required by enzymes
110
What is a coenzyme?
Organic cofactors that accept electrons from an enzyme and transfer them to another enzyme
111
What are metabolic pathways?
Chains of reactions with each step catalyzed by a different enzyme
112
What are nucleotides?
Organic compounds with nitrogenous base, a monosaccharide, and one or more phosphate groups
113
What is Adenosine Triphosphate (ATP)?
The body's most important energy-transfer molecule which briefly stores energy and releases it for physiological work
114
What is phosphorylation?
The Pi released from ATP that are added to enzymes or other molecules to activate them
115
What is Guanosine Triphosphate (GTP)?
Nucleotide also involved in energy transfers
116
What is cAMP?
A nucleotide formed by the removal of two Pi groups from ATP, and acts as a "second messenger"
117
What are nucleic acids?
Polymers of nucleotides
118
What is Deoxyribonucleic Acid?
Polymers of nucleotides that constitute our genes
119
What is Ribonucleic Acid?
Polymers of nucleotides that carry out the DNA instructions and synthesize the proteins
