Chapter 2: Chemical Level Of Organization Flashcards
1
Q
How many chemical elements are present in your body?
A
26
2
Q
What are the 4 major elements that constitute 96% of your body mass?
A
O, C, H, N
3
Q
What are the 8 elements that constitute 3.6% of your body mass?
A
Ca, P, K, S, Cl, Mg, Fe, and Na
4
Q
How many trace elements are in your body?
A
14
5
Q
What is the nucleus?
A
The dense core of an atom
6
Q
How many electrons do the first 3 shells hold?
A
First holds 2, second holds 8 and third holds 18
7
Q
Why is an atom usually electrically neutral?
A
Because the number of protons equals the number of electrons
8
Q
What is the atomic number and atomic mass?
A
Atomic number is the number of protons. Atomic mass is the number of protons + neutrons
9
Q
What are isotopes?
A
Atoms that have different numbers of neutrons so have different mass numbers
10
Q
What is a stable isotope?
A
It’s nuclear structure doesn’t change over time.
11
Q
What’s a radioactive isotope? Give some examples
A
Unstable. Their nuclei decay into stable configuration (H-3, C-14, O-15, O-19)
12
Q
Explain how radioactive isotopes can be harmful
A
They can break apart molecules thus posing a threat to human body by producing tissue damage or causing various types of cancer
13
Q
Name some benefits of radioactive isotopes
A
For diagnostic or treatment purposes. Used as tracers to follow movement of certain substances through the body. Iodine-131 detects cancer of thyroid gland. Cesium-137 used to treat advanced cervical cancer.
14
Q
What is the Atomic Mass?
A
Average mass of all its naturally occurring isotopes. Measured in Daltons and is usually close to the mass number
15
Q
What is a Dalton?
A
A unit for measure the mass of atoms and their subatomic particles
16
Q
What is an ion?
A
An atom that is electrically charged because it gives up or gains an electron… have a positive or negative charge
17
Q
Define ionization
A
Process of giving up or gaining an electron
18
Q
What is a molecule?
A
When 2 or more atoms share electrons
19
Q
What is included in a molecular formula?
A
The elements and the number of atoms of each element that make up a molecule (O2… molecule contains 2 atoms of oxygen)
H2O… one oxygen atom shares electrons with 2 hydrogen atoms
20
Q
What is a compound?
A
A substance that contains atoms of 2 or more different elements (H2O and NaCl)
21
Q
What is a Free Radical?
A
An atoms / group of atoms with an unpaired electron in its outer shell… highly unstable and reactive and destructible to nearby molecules
22
Q
How does a free radical become stable?
A
Either by giving up the unpaired electron or by gaining an electron from another molecule
23
Q
What are some sources of free radicals and what are some illnesses that may be associated with free radicals?
A
Sources: UV from sun, X-rays, some reactions occur during normal metabolic processes.
Diseases: Cancer, atherosclerosis, Alzheimer’s, DM, cataracts, rheumatoid arthritis, aging
24
Q
Why are antioxidants important?
A
They inactivate oxygen-derived free radicals. So may slow down aging!
25
What atoms are most likely to bind with others?
Atoms who do not have a filled valence shell
26
What is the Octet Rule?
Explains why atoms act in predictable ways. One atom will be more likely to bind with another if doing say will leave both of them with 8 electrons in its valence shell
27
What are the 3 types of chemical bonds?
Ionic, covalent, and hydrogen
28
What is an ionic bond?
A force of attraction that holds together 2 ions with opposite charges. Ie Na+ and Cl- create NaCl (sodium chloride). When an atom of sodium donates its sole valence electron to an atom of chlorine the resulting positive and negative charges pull both ions tightly close together and an ionic bond is formed.
29
What's an electrolyte?
Ionic compound that breaks apart into positive and negative ions in a solution... the solutions conduct a negative current
30
What's a covalent bond?
Two or more atoms SHARE electrons rather than gaining or losing them. The larger the number of electron pairs share between the 2 atoms the stronger the bonds. Can be single, double or tripple covalent bonds
31
What's a non-polar covalent bond?
Sharing of electrons between 2 atoms is equal. One atom does not attract the shared electrons more strongly. Such as all bonds between 2 identical atoms.
32
What is a polar covalent bond?
Sharing of electrons betwee 2 atoms is UNEQUAL. Nucleus of one atom attracts the shared electrons more strongly than the nucleus of the other atom. Resulting molecule has a negative charge near the atom that attracts electrons more strongly (this atom has electronegativity... power to attract electrons to itself). At least one other atom in the molecule will have a positive charge. H2O... oxygen atom has greater electronegativity
33
What are hydrogen bonds?
Forms when a H atom with a partial + charge attracts the partial negative charge of neighbouring electronegative atoms... usually O or N atoms. . Results from attraction of oppositely charged parts of molecules rather than from sharing electrons (covalent) or loss/gain of electrons (ionic). Weakest bond. Can't bind atoms into molecules.
34
What is cohesion?
Hydrogen bonds that link neighbouring water molecules give water considerable cohesion which is the tendency of like particles to stay together. Cohesion of water molecules creates high SURFACE TENSION, a measure of the difficulty of stretching or breaking the surface of a liquid. The boundary between water and air means that surface tension is very high. Hydrogen bonds, when many act together, provide lots of strength and stability. When we breathe, each inhalation must have enough force to overcome the opposing effect of surface tension as the air sacs stretch and enlarge when taking in air
35
What is a acid?
A substance that dissociates (separate into ions and surrounded by water molecules) into one or more hydrogen ions (H+) and one or more anions. Acid is a proton donor because H+ is a single proton with a charge
36
What's a base?
Dissociate into one or more hydroxide ions (COH-) and one or more cations. It's a proton acceptor because it removes H+ from solution.
37
What is salt?
When dissolved in water it dissociates into cations and anions (neither of which is H+ or OH-). Salt like potassium chloride are electrolytes responsible for carrying electrical currets epseiclaly in nerve and muscle tissue. Acids and bases react with one another to form salts
38
What is the pH scale?
Expresses acidity and alkilinity. 0-14. Based on concentration of H+ per mole per L. More H+ ions, the more acidic. More OH- than H+ = basic. Higher numbers are basic.
39
What are buffer systems?
Convert strong acids and bases into weak acids and bases.
40
Strong acids/bases vs weak acids/bases?
Strong acids/bases ionize easily and contribute many H+ (or OH-) ions to solutions which can disrupt body's metabolism. Weak acids/bases don't ionize as much and contribute fewer H+ or OH- so have less affect on pH
41
What are buffers?
Chemical compounds that can convert strong acids/bases into weak ones by adding or removing protons (H+)
42
What is the carbonic acid - bicarbonate buffer system?
Carbonic acid (H2CO3) can act as a weak acid and the bicarbonate ions (HCO3) acts as a weak base. Compensates for an excess or shortage of H+. HCO3 is a weak base and compensates for an excess or shortage of H+. H2CO3 acts as a weak acid and provides the needed H+.
43
Why is carbon useful to living organisms?
Can form bonds with 1-1000 other carbon atoms to produce large molecules with different shapes. Useful for building body structures because the molecules are big and many don't dissolve easily in water. 4 electrons in valence shell.
44
Define a Carbon Skeleton
Chain of C atoms in organic molecules
45
Define a hydrocarbon
Many carbons are bounded to H atoms
46
What are functional groups?
Other atoms/molecules bound to the hydrocarbon skeleton
47
What are some major functional groups of organic molecules?
Hydroxyl, sulfhydryl, carbonyl, carboxyl, ester, phosphate, amino acids
48
What are macromolecules?
Small organic molecules combined into very large molecules
49
What are Polymers?
A large molecule formed by the covalent bonding of many identical/similar small building block molecules called monomers. MACROMOLECULES are polymers. Two monomers are usually joined by dehydration synthesis
50
What are isomers?
MOlecules with the same molecular formula but different structures so have different chemical properties.
51
What are carbohydrates?
Includes sugars, glycogen, starches, cellulose. Source of chemical energy for generating ATP needed to drive metabolic processes. C, H and O are elements of carbohydrates. Ratio of H to O is 2:1.
52
What are the 3 main groups of carbohydrates?
Monosaccharides, disaccharides, and polysaccharides.
53
What are monosaccharides?
The monomers of carbohydrates. Contains 3-7 C atoms. End in "ose". Prefix indicates the number of C atoms. Hexose glucose broken down to produce ATP.
54
What are disaccharides?
Molecule formed from the combination of 2 monosaccharides by dehydration synthesis. For example fructose and glucose cmbine to form the disaccharide sucrose. Disaccharides can be split into smaller simpler molecules by hydrolysis.
55
What are polysaccharides?
Contains hundreds of monosaccharides joined through dehydration syntheses. Usually insoluble in water. Glycogen is the main polysaccharide in the body (is made up of glucose monomers).
56
Name two polysaccharides
Starches and cellulose. Cellulose can't be digested by humans and starches are found in food like pasta and potatoes and are a major source of carbohydrates for the body.
57
What are lipids?
Organic compounds. Contains C, O, and H. But the H and O don't have a 2:1 relationship... proportion of electronegative O atoms is smaller in lipids than carbohydrates. So fewer covalent bonds. Most lipids are insoluble in polar solvents like water.
58
What are lipid proteins?
Lipid-protein complexes that are soluble because the proteins are on the outside and lipids on the inside.
59
What is glycogen?
Stored form of carbohydrate in the human body
60
What are some lipids?
Fatty acids, triglycerides (fats and oils), phospholipids, steriods, eicosanoids, fat soluble vitamins (A, D, E and K) and lipoproteins
61
What are fatty acids?
They synthesize triglycerides and phopholipids. Simplest. Catabolized to generate ATP. Consists of hydroxyl groups and a hydrocarbon. Can be saturated and unsaturated.
62
What are saturated fatty acids?
Has single covalent bonds between C atoms and hydrocarbon chain. Each carbon atom of the hydrocarbon chain is saturated with hydrogen atoms.
63
What are unsaturated fatty acids?
Has one or more double covalent bonds between C atoms and the hydrocarbon chain. Therefore the fatty acid is not completely saturated with H atoms (see diagrams). Kink at the site of the double bond.
64
What is monounsaturated? What is polyunsaturated?
One double bond in hydrocarbon chain and one kink. More than one double bond in hydrocarbon and more than one kink
65
What are triglycerides?
Most plentiful lipids in the body. Consists of 2 types of building blocks: Single glycerol molecule and 3 fatty acid molecules. 3-carbon glycerol molecule forms the backbone of triglycerides. 3 fatty acids are attached via dehydration synthesis.
66
What's an ester linkage?
CHemical bond formed where each water molecule is removed
67
How does hydrolysis affect triglycerides?
Breaks down a single molecule of a triglyceride into 3 fatty acids and glycerol.
68
What is saturated fat?
Fat that consists mainly of saturated fatty acids. Lacks double bonds so they can pack close together and solidify into solid. Occurs mostly in red meats and non-skim dairy products.
69
What is oil?
Triglyceride that's a liquid at room temperature. Unsaturated fatty acids. Contains one or more double bonds in hydrocarbon chain. Kinks prevent them from packing close together.
70
What is monounsaturated fats?
Oil. Contains triglycerides that contain monounsaturated fatty acids. Olive oil, peanut oil, canola oil.
71
What is polyunsaturated fats?
Oil. Has triglycerides that mainly consist of polyunsaturated fatty acids. Corn oil, sunflower oil, soybean oil, fatty fish
72
What are phospholipids?
Glycerol backbone and 2 fatty acid chains attached to the first 2 carbons. A phosphate group (PO4 3-) links a small charged group that contains N to the backbone and is called "the head". The head is polar and can form H bonds with water molecules. The tails (2 fatty acids) are non polar and only interacts with other lipids
73
What is Amphipathic?
MOlecules that have both polar and nonpolar parts
74
What are steroids?
Structure differs from triglycerides. Has 4 rings of C atoms
75
What are sterols?
Steroids that have one hydroxyl group (alcohol) (-OH)
76
What are some steroids?
Cholesterol, estrogen and testosterone, cortisol, bile salts, vitamin D
77
What is Eicosanoids?
Lipids derived from a 20 carbon fatty acid called arachidonic acid. There are two subclasses: Prostaglandins and leukotrienes
78
What do prostaglandins do?
MOdify responses to hormones, contribute inflammatory responses, prevent stomach ulcers dilate airways to lungs, regulate body temperature, influence formation of blood clots
79
Define chemical reaction
Occurs when new bonds form or old bonds break between atoms. Interactions of valence electrons is the basis of chemical reactions
80
Reactants vs products
Reactants are the starting substance and products are the end substance. Total mass of reactants equals total mass of products.
81
Define metabolism
All chemical reactions occurring in body
82
Potential vs kinetic energy
Potential energy is the energy stored by matter due to its position. Kinetic energy is associated with matter in motion. Potential energy converts to kinetic.
83
What's chemical energy?
Form of potential energy that's stored in the bonds of compounds and molecules
84
Law of Conservation of Energy
Matter can't be destroyed or made. Can only be converted from one form to another
85
Exergonic reactions
Releases more energy than absorbs. Occurs as nutrients like glucose breaks down
86
Endergonic reactions
Absorbs more energy than it releases. Energy released from an exergonic reaction used to drive endergonoc one
87
What's activation energy?
The collision energy needed to break chemical bonds
88
What are 2 things that will influence the change a collision occurs?
1) concentration: more particles of matter present in a confined space = higher chance of collision. 2) temperature: as temp rises particles move faster
89
What are catalysts?
Chemical compounds that speed up reactions by lowering the activation energy needed for a reaction to occur
90
What are synthesis reactions?
When 2 or more atoms, ions or molecules are combined to form larger molecules. Anabolism (endergonoc because they absorb more than they release)
91
Decomposition reactions
Split up larger molecules into smaller atoms, ions and molecules. Catabolism ( exergonic because they release more energy than absorbed)
92
Exchange reactions
Consist of both synthesis and decomposition reactions. "Switching partners"
93
Reversible reactions
The products revert back to their original reactants indicated by 2 half arrows pointing in opposite directions. May require catalysts called enzymes
94
Oxidation- reduction reactions
Essential for all life. Breaks down food molecules to produce energy. Oxidation is loss of electronics and in the process the oxidized substance releases energy. Reduction is gain of electrons and in the process the reduced substance gains energy. When one substance is oxidized the other is reduced at same time. When a food molecule like glucose is oxidized the energy produced is used by a cell to carry out various functions
95
What are inorganic compounds
Usually lack C. Few atoms and don't perform complex biological functions. Water, many salts, acids, bases . CO2, bicarbonate (HCP3) and carbonic acid (H2CO3) are inorganic and contain C.
96
Organic compounds
Always contain C. Usually contains H. Always covalent bonds.
97
What is water's most important feature and why?
It's polarity. Makes water a great solvent for other ionic compounds or polar substances, gives water molecules cohesion and allows water to resist temp changes. THINK ABOUT HOW SALT DISSOLVES IN IT
98
Give and example of a solvent and solute
Water as a solvent and salt as a solute
99
Hydrophilic
Dissolves easily I'm water. Polar covalent bonds
100
Hydrophobic
Not water soluble. Non polar covalent bonds
101
Why is water a good medium for metabolic reactions?
Water allows dissolved reactants to collide and form products
102
Hydrolosys
Decomposition reactions break down large nutrient molecules into smaller molecules by adding water.
103
Dehydration-synthesis reaction
Water molecule is one of the products formed
104
What's a thermal property of water
Water can absorb and release lots of heat without a huge change in temp. It has lots of H bonds so some of the heat used to break up these bonds. Helps maintain temp homeostasis
105
How is water used in the body
As libricating fluid. In the pleural and pericardial cavities. Abdomen (peristalsis cavity) where internal organs slide over each other. Joints (bones ligaments and tendons runs against each other)
106
What's a Mixture
Combination of elements or compounds that are physically blended together but not bound by chemical bonds. Air is a mixture of gases.
107
What's a solution
Very small particles so looks transparent
108
What's a colloid?
Solute particles are big enough to scatter light (translucent or opaque)
109
What's a suspension?
Suspended material may mis with liquid or suspending medium but will eventually settle out (like blood. RBCs settle at the bottom and plasma is upper layer).
110
2 ways to express the concentration of a solution?
1) mass per volume percentage (relative mass of a solute found in a given volume of solution). 2) Moles per litre (mil/L): total number of molecules in a volume of solution (a joke is the amount of any substance that has a mass equal to the sum of the atomic mass of all its atoms).
111
WHat to Leukotreines do?
Participate in allergic and inflammatory responses
112
What are proteins?
Large molecules that contain O, H, C and N. Some contain . More complex in structure than carbohydrates and lipids. Responsible for structure of body tissues. Examples enzymes, antibodies, some hormones
113
What are amino acids?
The monomers (or building blocks) of proteins. There are 20 different amino acids and each as an H atom and 3 functional groups (an amino group, a carboxyl group, and a side chain (R group). Each are joined via a covalent bond and this is called a PEPTIDE BOND (creates proteins). Dehydration synthesis reaction.
114
Dipeptide vs tripeptide vs polypeptide
Dipeptide is when 2 amino acids combine. Tripeptide is when an amino acid combines with a dipeptide. Polypeptide is 10-2000 or more.
115
What are the 6 types of proteins?
Structural, regulatory, contractile, immunological, transport, catalytic.
116
What are the levels of structural organizations in proteins?
Primary, secondary (helix and beta pleated sheet), tertiary (3D shape) and quaternary structure (arrangement of 2 or more polypeptide chains). Each variation in the number of sequence of amino acids produces a different protein.
117
What is the primary structure of protein?
Amino acids linked by covalent bonds. Genetically determined. When something goes wrong with one, it can cause disorder. Like SCD... nonpolar amino acids replace polar.
118
What is the secondary structure of a protein?
Repeated twisting or folding of neighbouring amino acids in the polypeptide chain. Examples: Alpha helix (clockwise spirals) and beta pleated sheets. Stabalized by H bonds that form at regular intervals
119
What's a tertiary structure in a protein?
3D shape of a polypeptide chain. Unique structure determines how it will function. Folding pattern is determined by disulfide bridges (form between the sulfhydryl groups of 2 monomers of amino acid cysteine) and weak bonds like H bonds, ionic bonds, and hydrophobic interactions.
120
What is the quaternary structure of proteins?
Contains several polypeptide chains
121
What are the 2 classes of proteins?
Fibrous and globular
122
What are fibrous proteins?
Insoluble, polypeptide chains are lone and parallel. Collagen (strenghtens bones, ligaments and tendons), elastin (stretches skin, blood vessels, lung tissue), keratin (forms structure of hair and nails, waterproofs), dystrophin (reinforces parts of muscle cells), fibrin, (forms blood clots) actin and myosin (contractions of muscles, division in cells, and trnsport of substances within cells)
123
What are globular proteins?
Soluble, polypeptide chains are spherical, metabolic functions. Enzymes, antibodies and complement proteins, hemoglobin (trnsports O), lipoproteins (transports lipids and cholesterol), albumins (help regulate blood pH), membrane proteins (transports substances out of cells)
124
What is denaturation?
When a protein encounters an altered environment and unravels and loses its characteristic shape so proteins no longer functional. This is why homeostasis is important.
125
What are enzymes?
Catalysts. Two parts: Protein part (apoenzyme) and nonprotein part (cofactor)
126
What's a cofactor?
A type of enzyme and can be metal (iron, zinc, Mg, Ca) or an organic molecule called coenzyme (often derived from vitamins)
127
What are the 3 important parts of enzymes?
1)Enzymes are highly specific. Each binds to a particular substrate (reactant molecules in which enzymes act). 2) Enzymes are very efficient. Can catalyze reactions 100 million to 10 billion times faster than similar reactions without enzymes. 3) Enzymes are subject to a variety of cellular controls. Their role in synthesis and concentration are under control by the cell's genes.
128
What are nucleic acids?
Huge organic molecules that contain C, O, H, N, and P.
129
What is DNA?
Forms the inherited genetic material. Each gene is a segment of DNA molecules. Controls protein synthesis and acitivities in our cells.
130
What is RNA?
Relays instructions from the genes to guide each cell's synthesis of proteins from amino acids
131
What are nucleotides?
The monomers that repeat in the nucleic acid chain. Each nucleotide has 2 parts: Nitrogenous base, pentose sugar, and phosphate group
132
What is the nitrogenous base part of a nucleotide?
All contain C, H, O and N. Adenosine (A), thymine (T), cytosine (C) and Guanine (G). A and G are large and called purines. T and C are small and called pyrimidines.
133
What is the pentose sugar part of a nucleotide?
A 5 carbon sugar called deoxyribose attaches to each DNA base
134
What is the phosphate group of a nucleotide ?
Phosphate groups alternate with pentose sugars to form the backbone of a DNA strand
135
What's the Watson-Crick Double Helix model look like?
DNA resembles a spiral ladder
136
What is RNA?
Single stranded. Ribose (sugar), pyrimidine thymine is replaced with uracil (U). MRNA, rRNA, tRNA
137
What is Adenosine Triphosphate (ATP)?
Energy currency of the cell. ATP transfers the energy liberated in exergonic catabolic reactions to power cell activities (endergonic reactions). 3 phosphate groups attached to adenosine. ATPase is the enzyme that catalyzes the hydrolosys of ATP.
138
What are the 2 phases of cellular respiration?
1) Anaerobic phase: Reactions that don't require O, glucose is partially broken down by a series of catabolic reactions into pyruvic acid. Each glucose molecule converted into pyruvic acid molecule yeilds 2 molecules of ATP. 2) Aerobic phase: in presence of O, glucose is completely broken down into CO2 and water. Generates heat and 30-32 ATP molecules.
