Chapter 2 Flashcards
1
Q
Mass
A
Equal to the amount of matter in an object and remains constant
2
Q
Kinetic energy
A
Energy in action
3
Q
Potential energy
A
Stored energy or inactive energy that has the capability to do work but is not presently doing so (ex. batteries in an unused toy). When potential energy is released it becomes kinetic.
4
Q
Forms of energy
A
Chemical, electrical, mechanical, and radiant (electromagnetic radiation)
5
Q
Chemical energy
A
Form stored in the bonds of chemical substances. Energy is captured temporarily in the bonds of ATP (adenosine triphosphate) later the bonds are broken and the stored energy is released
6
Q
Electrical energy
A
Results from the movement of changed particles. Electrical currents are generated when charged particles (ions) move along cell membranes. The nervous system uses nerve impulses (or action potentials) to transmit messages in the body.
7
Q
Mechanical energy
A
Energy directly involved in moving matter (ex. riding a bike)
8
Q
Radiant energy
A
(a.k.a electromagnetic radiation) is energy that travels in waves. These waves are called electromagnetic spectrum they include radio waves, microwaves, infrared waves, and x-rays.
9
Q
Energy conversions
A
Some of the initial energy supply is always “lost” to the environment as heat. It isn’t lost but it is unusable.
10
Q
Elements
A
Unique substances that cannot be broken down into simpler substances by ordinary chemical methods. There are 118, of those 92 occur in nature. Carbon, oxygen, hydrogen, and nitrogen make up about 96% of body weight.
11
Q
Physical properties
A
Those we can detect with our senses (color and texture) or measure (boiling hand freezing point)
12
Q
Chemical properties
A
Describe the way atoms interact with other atoms (bonding behavior)
13
Q
Nucleus
A
Central in the atom and contains protons and neutrons and surrounded by electrons
14
Q
Planetary model
A
Electrons move around the nucleus in fixed, circular orbits. Can’t determine the exact locations of elections bc they move around
15
Q
Orbitals
A
Regions around the nucleus in which an electron or electron pair is likely to be found most of the time.
16
Q
Orbital model
A
Useful for predicting the chemical behavior of atoms. It depicts probable regions of greatest electron density by denser shading (this haze is called the electron cloud)
17
Q
Size of atoms
A
Hydrogen: 1 proton, 1 electron, no neutrons
Helium: 2 protons, 2 electrons, 2 neutrons
Lithium: 3 protons, 3 electrons, 4 neutrons
18
Q
Atomic number
A
It is equal to the number of protons in its nucleus and is written as a subscript to the left of its atomic symbol.
19
Q
Mass number
A
The sum of the masses of its protons and neutrons. Indicated by a superscript to the left of its atomic symbol.
20
Q
How do you find the number of subatomic particles?
A
The atomic number (protons), the atomic number (neutrons), mass number minus atomic number (number of neutrons)
21
Q
Isotopes
A
Two or more structural variations of elements. They have the same number of protons and electrons (and chemical properties), but they differ in the number of neutrons.
22
Q
Atomic weight
A
An average of the weights (mass numbers) of all isotopes of an element. Atomic weight is approximately equal to the mass number of its most abundant isotope.
23
Q
Radioisotopes
A
The process of atomic decay is radioactivity and isotopes that exhibit this behavior are called radioisotopes. The disintegration of a radioactive nucleus occurs Whalen subatomic alpha particles (packets of 2p+2n), beta particles (electron-like particles), or gamma rays (electromagnetic energy) are ejected from the atomic nucleus
24
Q
Quarks
A
Dense nuclear particles are composed of smaller particles called quarks that associate in one way to form protons and in another way to form neutrons
25
Molecule of that element
Two or more of the same element combine that results in a substance
26
Compound
Two or more different kind of atoms bind. They are chemically pure and all of their molecules are identical.
27
Mixtures
Substances composed of two or more components physically intermixed. There are three types: solutions, colloids, and suspensions
28
Solutions
Homogenous (same composition throughout) mixtures of components that may be solids, liquids, or gases (ex. air and seawater). The substance present in the greatest amount is called the solvent or dissolving medium (usually liquids). Substances present in smaller amounts (dissolved in the solvent) are called solutes.
29
True solutions
Gases, liquids, or solids dissolved in water (ex. saline and mineral water). They are usually transparent.
30
Concentration of solutions
Describe in terms of the percent (parts per 100 parts) of the solute in the solution. Water is assumed to be the solvent.
31
Mole
A mole of any element or compound is eqaul to its atomic weight or molecular weight (sum of the atomic weights) in grams. Express the concentration of a solution in terms of its molarity (moles per liter indicated by M)
32
Avogadro’s number
One mole of any substance always contains exactly the same number of solute particles, that is 6.02 x 10^23
33
Colloids
(aka emulsions) are heterogenous mixtures, which means their composition is dissimilar in different areas of the mixture. Solute particles are larger than those in true solutions but it does not settle out. They can go through sol-gel transformations (change from a fluid to a more solid state). Ex. cytosol
34
Suspensions
They are heterogenous mixtures with large, often visible solutes that tend to settle out (ex. sand and water, blood)
35
Difference between mixtures and compounds
Mixtures: no chemical bonding, can be separated by physical means (strainer), some homogenous and some heterogenous,
Compounds: separated only by chemical means (breaking bonds),
36
Covalent bonds
Electrons are shared to achieve stability. That produces molecules in which the shared electrons occupy a single orbital common to both atoms.
37
Ionic bonds
A chemical bond between atoms formed by the transfer of one or more electrons from one atom to another. The atom that gains one or more electrons is the electron acceptor. It acquires a net negative charge am dis called an anion. The atom that loses electron is the electron donor. It acquires a net positive charge called a cation. They stay close. (ex. forming salt)
38
Hydrogen bonds
Attraction between a hydrogen atom carrying a partial positive charge and an electronegative atom with a slightly negative charge. Weakest bond. Common between dipoles bc the slightly negative oxygen of one molecule attract the slightly positive hydrogen atoms of other molecules.
39
Nonpolar molecules
Molecules formed are electrically balanced. They do not have separate + and - poles of charge.
40
Polar molecules
Unequal electron pair sharing especially in nonsymmetrical molecules containing atoms with different electron-attracting abilities.
41
Electronegativity
Small atoms with 6 or 7 valence shell electrons attract electrons very strongly.
42
Electropositive
Only one or two valence shell electrons. Their electron-attracting capabilities is so low that they lose their valence shell electrons to other atoms.
43
Chemical reaction
When chemical bonds are formed, rearranged, or broken
44
Chemical equations
A number written as a subscript indicates that the atoms are joined by chemical bonds. A number written as a prefix denotes the number of unjoined atoms or molecules (ex. 4H+C (reactant) -> CHv4 (product))
45
Reactants
The number and kinds of the interacting substances
46
Products
The chemical composition of the result of the reaction
47
Relative proportions
Balanced equations indicate the relative proportion of each reactant and product
48
Synthesis reactions
Smaller particles are bonded together to form larger, more complex molecules (ex. Amino acids are joined together to form a protein molecule)
49
Decomposition reactions
Bonds are broken in larger molecules, resulting in smaller, less complex molecules (ex. glycogen is broken down to release glucose molecules)
50
Exchange reactions
Bonds are both made and broken (aka displacement reactions) ex. ATP transfers its terminal phosphate group to glucose to form glucose-phosphate
51
Oxidation-reduction reactions
(aka redox reactions) decomposition reactions that are the basis of all reactions in which food fuels are broken down for energy. Electrons are exchanged between the reactants. The donor is oxidized and the acceptor is reduced. Also form when ionic compounds are formed.
52
Exergonic reactions
They release energy with less energy than the initial reactants (ex. catabolic and oxidative)
53
Endergonic reactions
Products of energy absorbing reactions contain more potential energy in their bonds that the reactants (ex. anabolic)
54
Factors that affect the rate of chemical reactions
Temperature, concentration, particle size, and catalysts
55
Properties of water
High heat capacity, high heat of vaporization, polar solvent properties, universal solvent, layers of water molecules (hydration layers) around large charged molecules (proteins) aka biological colloids, reactivity, and cushioning
56
Salts
Ionic compound containing cations other than H+ and anions other than the hydroxyl ion (OH-). The most plentiful salts are calcium phosphates that make bones and teeth hard
57
Acids
Can react with (dissolve) many metals. Substance that release hydrogen ions in detectable amounts. They are proton donors.
58
Bases
They are proton acceptors (take up hydrogen ions in detectable amounts. A common inorganic base is hydroxides. These disassociate when dissolved in water.
59
pH units
Relative concentration of hydrogen ions in various body fluids measured in concentration units. Runs from 0-14 and is logarithmic. At a pH of 7 the solution is neutral, neither acidic nor basic. Below 7 is basic and above 7 are alkaline.
60
Neutralization
Acids and bases are mixed and react with each other in displacement reactions to form water and a salt.
61
Buffers
Homeostasis of acid-base balance is regulated by chemical systems (proteins and other types of molecules). They resist large swings in pH by relying hydrogen ions (acting as acids) when the pH rises and binding hydrogen ions (acting as bases) when it drops. They have a weak acid and weak base.
62
Dehydration synthesis
Monomers join together. A hydrogen atom is removed from one monomer and a hydroxyl group is removed from the monomer it is to be joined with. As a covalent bond unites the monomers, a water molecule is released.
63
Hydrolysis
Opposite of dehydration synthesis in which molecules are degraded.
64
Carbohydrates
A group of molecules that includes sugars and starches. They contain carbon, hydrogen, and oxygen. The hydrogen and oxygen occur in the same 2:1 ratio as in water.
65
Monosaccharides
Or simple sugars, are single chain ir single ring structures containing from 3 to 7 carbon atoms. CHO comes in 1:2:1 ratio. (CHv20)vn (ex. pentose and hexose like deoxyribose and glucose)
66
Isomer
Have the same molecular formula, but their atoms are arranged differently giving the, different chemical properties
67
Disaccharides
Or double sugar, is formed when two monosaccharides are joined by dehydration synthesis. A water molecule is lost as the bond is made. (ex. sucrose, lactose, and maltose)
68
Polysaccharides
Polymers of simple sugars linked together by dehydration synthesis. They are used for storage bc they are large and fairly insoluble. (ex. starch and glycogen)
69
Starch
The storage carbohydrate formed by plants. We are unable to digest cellulose. It’s is important in providing the bulk (one from of fiber) that helps move feces.
70
Glycogen
The storage carbohydrate of animal tissues, is stored primarily in skeletal muscle and liver cells. Liver uses it to store and maintain blood sugar (glucose) levels.
71
Carbohydrate functions
Provide easy source of cellular fuel, can be broken down and oxidized
72
Lipids
Insoluable in water but dissolve quickly in other lipids and organic solvents such as alcohol and ether. All contain carbon, hydrogen, and oxygen at a lower proportion of oxygen. They include triglycerides, phospholipids, steroids, and others.
73
Triglycerides
They are fats when solid or oils when liquid. Composed of two building blocks, fatty acids and glycerol. The fat deposits protect and insulate body organs. Major form of stored energy.
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Saturated fat
Molecules are packed close together forming a solid. There are no double bonds between carbons.
75
Unsaturated fat
Molecules cannot pack together close enough to solidify bc of kinks in the chain. There is a doble bond between one pair of carbons in one of the fatty acids.
76
Phospholipids
They are modified triglycerides that have two fatty acid chains. The third chain is replaced by a phosphate group with an attached nitrogen group. Chief components of cell membranes and helps transport lipids in blood.
77
Steroids
Flat molecules made of four interlocking hydrocarbon rings. They are fat soluble and contain little oxygen. (ex. cholesterol (starting molecule for synthesis of all body steroids), vitamin D, sex hormones, bile salts)
78
Eicosanoids
Diverse lipids chiefly derived from a 20-carbon fatty acid (arachidonic acid) found in all cell membranes. Prostaglandins are important bc they play roles in blood clotting, regulation of blood pressure, inflammation, and labor contractions.
79
Protein
Composes 10-30% of cell mass am dis the basic structural material of the body. Many play roles in cell function. They include enzymes (biological catalyts), hemoglobin of the blood) and contractile proteins of muscle, and have the most varied functions.
80
Protein functions
Structural proteins (mechanical support), enzyme proteins (catalysis and biochemical reactions), transport proteins (moving substances in blood or across plasma membranes), contractile proteins (movement), communication proteins (transmitting signals between cells and chemical messengers or receptors), defensive proteins (protect against disease)
81
Amino acids
The building blocks of proteins. They have two groups: a basic group called amine and a an organic acid group. It can be a base (proton acceptor) or an acid (proton donor). There are only differences in their R group.
82
Peptide bond
Acid end of one amino acid links to the amine end of the next. The resulting bond produces an arrangement of linked atoms called a peptide bond.
83
Dipeptide
Two united amino acids
84
Tripeptide
Three united amino acids
85
Polypeptide
10 or more united amino acids. More than 50 is a protein.
86
Protein primary structure
Sequence of amino acids forms the peptide chain.
87
Protein secondary structure
The primary chain forms spirals (helices) and sheets. The most common is that alpha (a)-helix.
88
Alpha (a)-helix
Formed by coiling the primary chain and is stabilized by hydrogen bonds formed between NH and CO groups. Always link different parts of the same chain together.
89
Beta (B)-pleated sheet
They don’t coil, but at linked side by side by hydrogen bonds to form ribbonlike structure like an accordion. May link together different parts of the same chain that has folded back onto itself.
90
Protein tertiary structure
Helical or pleated regions of the polypeptide chain fold upon one another to produce a compact ball-like, or globular, molecule. Hydrophilic R groups are on the outside and hydrophilic are on the inside.
91
Protein quarternary structure
Two or more polypeptide chains aggregate to form a complex protein.
92
Fibrous proteins
aka structural proteins form long strands. Most have tertiary or quarternary structure. They are insoluble in water and stable. Provide mechanical support and strength (ex. collagen)
93
Globular proteins
aka functional proteins, are compact, spherical proteins that have at least a tertiary structure. Not stable. They are water soluble and chemically active that provide immunity, regulate growth, transport, and catalysts (ex. antibodies, enzymes)
94
What happens when a protein is denatured?
Hydrogen bonds begin to break when pH drops or the temp rises above normal (physiological) levels. Proteins unfold and lose their three dimensional shape. Can be reversed.
95
Active sites
Specific arrangements of atoms where catalytic activity occurs. Fit and interact chemically with other molecules of complementary shape and charge.
96
Enzymes
Globular proteins that act as biological catalysts. They increase the speed of reactions.
97
2 characteristics of enzymes
Apoenzyme (the protein portion) and a cofactor. Together they form a holoenzyme. Cofactor may be an ion of a metal or an organic molecule. When derived from vitamins, the cofactor is a coenzyme.
98
Substrate
Sound stance on which an enzyme acts
99
Activation energy
The certain amount of energy q chemical reaction needs to be absorbed to prime the reaction. It is needed to alter the bonds of the reactants so they can be rearranged to be a product.
100
Enzyme action
STEP 1 substrates bonds to the enzymes active site, temporarily forming an enzyme-substrate complex
STEP 2 the enzyme-substrate complex undergoes internal rearrangements that form the products
STEP 3 the enzyme releases the products of the reaction
101
Nucleic acids
Composed of carbon, oxygen, hydrogen, nitrogen, and phosphorus are the largest molecules in the body. There are two major classes: deoxyribonucleic acid (DNA) and ribonucleic acid (RNA).
102
DNA
found in the nucleus of the cell where it constitutes genetic material aka genes. It replicates itself before the cell divides and provides instructions for building every protein in the body. Bases are adenine (A), guanine (G), cytosine (C), thymine (T).
103
RNA
Outside the nucleus and carries out orders for protein synthesis issues by DNA. Three varieties: messenger RNA, ribosomal RNA, and transfer RNA that are distinguished by size and shape. Single stranded or folded, it’s sugar is ribose, and it’s based are adenine (A), guanine (G), cytosine (C), uracil (U).
104
Structure of DNA
Two nucleotide chains held together by hydrogen bonds between bases. Alternating sugar and phosphate components form backbones and the joined bases form the rungs. A=T, G=C.
105
Structure of RNA
Single strands of nucleotides
106
Adenosine Triphosphate (ATP)
Some energy is captured and stored as small packets of energy in the bonds of ATP. It is the primary energy-transferring molecule in cells and provides energy that is immediately usable. It is an adenosine-containing RNA nucleotide with two additional phosphate groups. ATP can store energy bc it has three negatively charged phosphate groups.
107
Phosphorylation
Enzyme transfers the terminal phosphate group from ATP to another molecule. These phosphorylated molecules become temporarily energetic and capable of performing cellular work. However, they lose the phosphate group.
108
Adenosine Diphosphate (ADP)
Breaking the terminal phosphate group of ATP yields two phosphate groups and an inorganic phosphate group. Breaking it lets out energy and produces adenosine monophosphate (AMP).
