Module 2: Chemistry Intro Flashcards
(136 cards)
1
Q
units of matter in all chemical elements
A
Atom
2
Q
Atoms consist of
A
Nucleus, positively charged protons & neutrons & negatively charged electrons that move about the nucleus in different energy levels
3
Q
Proton
A
Positively charged
4
Q
Neutron
A
Neutral (no) charge
5
Q
Electron
A
Negatively charged
6
Q
Different atoms of the same chemical element that have same number of protons but different number of neutrons
A
Isotope
7
Q
Unstable isotope that emits energy
A
Radioactive isotope
8
Q
Atomic number
A
of protons in the nucleus of an atom and the usual number of electrons
9
Q
Mass number
A
The sum of the number of protons & neutrons in an elects nuclues
10
Q
An atom that has a positive or negative charge
A
An ion
11
Q
Positively charged ions
A
Cations
12
Q
Negative charged ions
A
Anion
13
Q
When two or more atoms share electrons
A
Molecule
14
Q
A compound is
A
The combination of two or more different atoms
15
Q
An electrically charged atom or group of atoms with a unpaired electron in its outermost shell
A
Free radical
16
Q
Antioxidant
A
Substances that inactivate oxygen-derived free radicals
17
Q
How are ions formed
A
When an atom loses or gains a valence electron
18
Q
Ionic bond
A
Negative & positive charged ions held together
19
Q
Dissociation of positive and negative ions
A
Electrolyte
20
Q
Holds positively & negatively charged ions together
A
Ionic bond
21
Q
Formed when atoms of molecules share electrons
A
Covalent bond
22
Q
Formed when the atoms of molecules share electrons
A
Covalent bonds
23
Q
Strongest & most common bond
A
Covalent bond
24
Q
Can be polar or non polar
A
Covalent bodn
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The polar covalent bonding of hydrogen to oxygen can allow for
Hydrogen bonds to form
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Two atoms associate with a hydrogen ion
Hydrogen bond
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These bonds are weak & cannot bind atoms into molecules; instead these bonds severe as links between molecules to provide strength & stability and help determine the three dimensional shape of large molecules
Hydrogen bonds
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Occurs when new bonds are formed or old bonds break between atoms
Chemical reaction
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Starting substances of chemical reaction
Reactants
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Products
The ending substance of chemical reactions
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The total mass of the reactants will be equal to the total mass of the products
The law of the conservation of mass
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All the chemical reactions occurring in an organism
Metabolism
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Energy
The capacity to do work
34
Forms of energy and chemical reactions
Potential energy (chemical energy) and kinetic energy
35
Energy stored by matter due to its position
Potential energy
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Energy stored in bonds of compounds or molecules
Chemical energy
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Energy associated with matter in motion
Kinetic energy
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occur when two or more atoms, ions, or molecules combine to form new and larger molecules
Synthesis reactions
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Synthesis reactions are anabolic or catabolic
These reactions are anabolic, which means that bonds are formed.
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decomposition reaction are anabolic or catabolic
These reactions are catabolic, which means that chemical bonds are broken in the process.
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the loss of electrons from a molecule, which results in a decrease in the potential energy of the molecule.
Oxidation
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the gain of electrons by a molecule, which results in an increase in the potential energy of the molecule
Reduction
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usually lack carbon and are simple molecules
Inorganic compounds
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always contain carbon and hydrogen always have covalent bonds, and usually contain oxygen.
organic compounds
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examples of inorganic compounds
water, salts, acids, bases - carbon dioxide and bicarbonate ion
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examples of organic compounds
carbohydrates, lipids, proteins, nucleic acids and ATP
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the most important and abundant inorganic compound in all living systems
Water
48
In what molecule does the uneven sharing of valence electrons confers a partial negative charge near the single oxygen atom and two partial positive charges near the two hydrogen atoms
In the water molecule
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the ideal medium for most chemical reactions in the body, and it participates as a reactant or product in certain reactions
Water
50
breaks large molecules down into simpler ones by adding a molecule of water
Hydrolysis
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Dehydration synthesis occurs when
two simple molecules join together, eliminating a molecule of water in the process.
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a measure of the difficulty involved to stretch or break the surface of a liquid
surface tension; which is created by the cohesion of water molecules
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When the molecules of inorganic acids, bases, or salts dissolve in water, they undergo
ionization or dissociation, meaning that they separate into ions
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Acids ionize into
one or more hydrogen ions (H+) and one or more anions (negative ions)
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Bases dissociate into
one or more hydroxide ions (OH-) and one or more cations (positive ions). Bases are proton acceptors.
56
When dissolved in water, a salt dissociates into
cations and anions, neither of which is H+ or OH-.
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[H+] > [OH-]
acid solutions
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[H+] < [OH-]
alkaline solutions
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a pH of 7.0 equals 10-7 or 0.0000001 moles of H+/L, which is
neutrality
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the pH of urine, saliva
6.3-6.6
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pH of blood
neutral, pH of 7.4
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Carbohydrates
sugars, starches, glycogen, and cellulose
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Carbohydrates
sugars, starches, glycogen, and cellulose
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Carbohydrates are divided into three major groups based on their size
monosaccharides, disaccharides, and polysaccharides
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Disaccharides are formed from two monosaccharides by
dehydration synthesis
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split disaccharides back into simple sugars
Hydrolysis
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the largest carbohydrates, are known as complex carbohydrates; they can include hundreds of monosaccharides
Polysaccharides
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The principal polysaccharide in the human body is
glycogen
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glycogen is stored where
in the liver and skeletal muscles
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joined by dehydration synthesis, and separated by hydrolysis
Monosaccharides
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contain carbon, hydrogen, and oxygen; however, unlike carbohydrates, they do not have a 2:1 ratio of hydrogen to oxygen
Lipids
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have fewer polar covalent bonds, and thus they are mostly insoluble in polar solvents such as water (they are hydrophobic)
Lipids
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soluble in non-polar solvents such as chloroform or alcohol
lipids
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the most plentiful lipids in the body and provide protection, insulation, and energy (both immediate and stored)
Triglycerides
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structurally similar to triglycerides and are important membrane components
Phospholipids
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composed of four rings of carbon atoms. Examples include dietary lipid cholesterol, and the sex hormones estrogen and testosterone
Steroids
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give structure to the body, regulate processes, provide protection, help muscles to contract, transport substances, and serve as enzymes.
Proteins
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Amino acids contain
carbon, hydrogen, oxygen, and nitrogen
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Amino acids are joined together in a stepwise fashion with each covalent bond joining one amino acid to the next, which forms a
peptide bond
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The denaturation of a protein by a hostile environment causes
a loss of its characteristic shape and function
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Different amino acids join together to form peptides, polypeptides, or proteins via dehydration synthesis. The bonds between the amino acids are
Peptide Bond
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Catalysts in living cells are called
enzymes
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speed up chemical reactions by increasing the frequency of molecule collisions, lowering the activation energy, and properly orienting colliding molecules
Enzymes
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huge organic molecules that contain carbon, hydrogen, oxygen, nitrogen, and phosphorus.
Nucleic acids
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forms the genetic code inside each cell and thus regulates most of the activities that occur in our cells throughout our lifetime
Deoxyribonucleic acid (DNA)
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carries instructions from the genes in the nucleus of the cell to guide how the ribosomes assemble amino acids into proteins
Ribonucleic acid (RNA)
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The basic units of nucleic acids which are composed of a nitrogenous base, a pentose sugar, and a phosphate group.
nucleotides
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The building blocks of all nucleotides are
one or more phosphate groups, a pentose sugar, and a nitrogen-containing base.The nitrogen-containing bases of nucleotides. The two pentose sugars of DNA and RNA
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building blocks of all nucleic acids
nucleotides
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huge organic molecules that contain carbon, hydrogen, oxygen, nitrogen, and phosphorus.
Nucleic acids
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forms the genetic code inside each cell and thus regulates most of the activities that occur in our cells throughout our lifetime
Deoxyribonucleic acid (DNA)
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carries instructions from the genes in the nucleus of the cell to guide how the ribosomes assemble amino acids into proteins.
Ribonucleic acid (RNA)
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nucleotides, which are composed of
a nitrogenous base, a pentose sugar, and a phosphate group.
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The basic units of nucleic acids
nucleotides
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The basic units of nucleic acids
nucleotides
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the principal energy-storing molecule in the body
adenosine triphosphate
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adenosine consits of
adenine and ribose
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ATP is made by
three phosphate groups connected to adenosine
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When energy is liberated from ATP, it is
decomposed to adenosine diphosphate (ADP) and phosphorus (P).
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manufactured from ADP and P using the energy supplied by various decomposition reactions, particularly that of glucose
ATP
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ATP produces energy responsible for
movement of muscles, movement of chromosomes during cell division, movement of structures within cells, transport of substances across cell membranes, and sythesis of larger molecules from smaller ones
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the enzyme that catalizes hydrolysis of ATP
atpase
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by addition of a water molecule, energy is liberated and leaves a molecule called
adenosine diphosphate
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the energy needed to attach a phosphate group to ADP in supplied mainly by the breakdown of glucose. the process is called
cellular respiration
104
Describe hydrogen bonds and give two examples of their importance in cells
Hydrogen bonds are extremely weak bonds between two atoms. They are important for giving proteins and enzymes their three-dimensional shapes, bonding specialized molecules such as hormones and receptors, and binding enzymes to substrates.
105
What is an ionic bond? Give an example of an inonically bonded molecule
An ionic bond is a weak bond between two oppositely charged ions. The bond breaks when the molecule is placed in water. An example is sodium chloride (table salt).
106
```
Give the approximate pH of the following:
Gastric juice
Tomato juice
Blood
Milk of magnesia
```
a) Gastric juice: 1.2–3.0
b) Tomato juice: 4.2
c) Blood: 7.35–7.45
d) Milk of magnesia: 10.5
107
What is an isotope?
Isotopes are atoms of the same element that differ slightly in mass. Different isotopes of the same element have the same number of protons, but more or less neutrons.
108
Define the term base.
When put in water, a base is a substance that dissociates into hydroxyl (OH-) ions and one or more cations. A base also can be described as having the capacity to pick up one or more hydrogen (H+) ions.
109
How is ATP the “energy currency” of the cell?
ATP releases energy stored in its two high-energy phosphate bonds.
110
Define the term acid.
When put in water, an acid is a substance that dissociates into hydrogen ions and one or more anions.
111
What is a buffer
A buffer is a combination of chemicals that minimizes changes in the pH of a solution when acids or bases are added
112
Identify the monosaccharides, and give three common examples.
Monosaccharides are the simple sugars made up of carbon, hydrogen, and oxygen. Examples are glucose, fructose, and deoxyribose.
113
Describe the structure of DNA.
DNA is a large molecule consisting of two helically wound chains of nucleotides. The two chains are held together by hydrogen bonding between the nitrogenous base pairs—adenine and thymine, and cytosine and granine.
114
Describe the functions of water that make it useful in the body
a) Water is a good solvent.
b) Water participates in chemical reactions vital to cells.
c) Water absorbs heat without significantly changing temperature.
d) Water acts as a lubricant.
115
What are nucleotides?
Nucleotides are the building blocks of nucleic acids. Nucleotides are made up of a nitrogen base, a pentose sugar, and one or more phosphate groups.
116
Three important types of lipids
a) Triglycerides ― energy storage
b) Phospholipids ― membrane structure
c) Steroids ― hormones membrane structure
117
List the four elements that make up about 96% of our body weight:
a) Carbon
b) Hydrogen
c) Oxygen
d) Nitrogen
118
What are the four chemical groups of an amino acid?
Hydrogen, Amine, Carboxyl, Side chain (R group)
119
what is a radioactive isotope
A radioactive isotope is an isotope that is unstable and emits radiation as it breaks down.
119
what is a radioactive isotope
A radioactive isotope is an isotope that is unstable and emits radiation as it breaks down.
120
Define the term salt, and give an example.
When put in water, a salt is a substance that dissociates into cations and anions neither of which is (H+) or (OH-). An example of a salt is sodium chloride.
121
What kind of a net charge is carried by a cation?
A cation is a positively charged ion.
122
What is an electrolyte?
An electrolyte is a substance such as a salt, an acid, or a base, that, when put in water dissociates or ionizes into ions. In solution, electrolytes conduct an electric current.
123
How does RNA differ from DNA chemically and physically?
Chemically, the RNA nucleotides are made up of the sugar ribose, whereas DNA nucleotides are made up of deoxyribose. Physically, RNA is usually a single-stranded molecule, whereas DNA is usually double-stranded. RNA uses the nitrogenous bases adenine, cytosine, granine, and uracil; whereas DNA uses the nitrogenous bases adenine, cytosine, guanine, and thymine.
124
Which of the following would be the smallest in size?
Electron
125
Which of the following is the most abundant inorganic substance in humans?
Water
126
The most plentiful lipid in the human body is:
Triglyceride
127
The more _____________ ions are present in a solution, the more basic the solution.
Hydroxide
128
Which of the following elements are found in carbohydrates
Oxygen/carbon/hydrogen
129
What type of bonds hold water molecules together?
Covalent bonds
130
Which of the following is considered to be neutral on the pH scale?
Pure water
131
Steroids are classified as
Lipids
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“Saturated fat” is saturated with
Hydrogen
133
The atoms of the isotopes of a particular element vary in their number of
Neutrons
134
Which element is needed for clotting and muscle contraction, and contributes to the hardness of teeth and bone?
Calcium
