Module 2: Chemistry Intro Flashcards
units of matter in all chemical elements
Atom
Atoms consist of
Nucleus, positively charged protons & neutrons & negatively charged electrons that move about the nucleus in different energy levels
Proton
Positively charged
Neutron
Neutral (no) charge
Electron
Negatively charged
Different atoms of the same chemical element that have same number of protons but different number of neutrons
Isotope
Unstable isotope that emits energy
Radioactive isotope
Atomic number
of protons in the nucleus of an atom and the usual number of electrons
Mass number
The sum of the number of protons & neutrons in an elects nuclues
An atom that has a positive or negative charge
An ion
Positively charged ions
Cations
Negative charged ions
Anion
When two or more atoms share electrons
Molecule
A compound is
The combination of two or more different atoms
An electrically charged atom or group of atoms with a unpaired electron in its outermost shell
Free radical
Antioxidant
Substances that inactivate oxygen-derived free radicals
How are ions formed
When an atom loses or gains a valence electron
Ionic bond
Negative & positive charged ions held together
Dissociation of positive and negative ions
Electrolyte
Holds positively & negatively charged ions together
Ionic bond
Formed when atoms of molecules share electrons
Covalent bond
Formed when the atoms of molecules share electrons
Covalent bonds
Strongest & most common bond
Covalent bond
Can be polar or non polar
Covalent bodn
The polar covalent bonding of hydrogen to oxygen can allow for
Hydrogen bonds to form
Two atoms associate with a hydrogen ion
Hydrogen bond
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
Occurs when new bonds are formed or old bonds break between atoms
Chemical reaction
Starting substances of chemical reaction
Reactants
Products
The ending substance of chemical reactions
The total mass of the reactants will be equal to the total mass of the products
The law of the conservation of mass
All the chemical reactions occurring in an organism
Metabolism
Energy
The capacity to do work
Forms of energy and chemical reactions
Potential energy (chemical energy) and kinetic energy
Energy stored by matter due to its position
Potential energy
Energy stored in bonds of compounds or molecules
Chemical energy
Energy associated with matter in motion
Kinetic energy
occur when two or more atoms, ions, or molecules combine to form new and larger molecules
Synthesis reactions
Synthesis reactions are anabolic or catabolic
These reactions are anabolic, which means that bonds are formed.
decomposition reaction are anabolic or catabolic
These reactions are catabolic, which means that chemical bonds are broken in the process.
the loss of electrons from a molecule, which results in a decrease in the potential energy of the molecule.
Oxidation
the gain of electrons by a molecule, which results in an increase in the potential energy of the molecule
Reduction
usually lack carbon and are simple molecules
Inorganic compounds
always contain carbon and hydrogen always have covalent bonds, and usually contain oxygen.
organic compounds
examples of inorganic compounds
water, salts, acids, bases - carbon dioxide and bicarbonate ion
examples of organic compounds
carbohydrates, lipids, proteins, nucleic acids and ATP
the most important and abundant inorganic compound in all living systems
Water
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
the ideal medium for most chemical reactions in the body, and it participates as a reactant or product in certain reactions
Water
breaks large molecules down into simpler ones by adding a molecule of water
Hydrolysis
Dehydration synthesis occurs when
two simple molecules join together, eliminating a molecule of water in the process.
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
When the molecules of inorganic acids, bases, or salts dissolve in water, they undergo
ionization or dissociation, meaning that they separate into ions
Acids ionize into
one or more hydrogen ions (H+) and one or more anions (negative ions)
Bases dissociate into
one or more hydroxide ions (OH-) and one or more cations (positive ions). Bases are proton acceptors.
When dissolved in water, a salt dissociates into
cations and anions, neither of which is H+ or OH-.
[H+] > [OH-]
acid solutions
[H+] < [OH-]
alkaline solutions
a pH of 7.0 equals 10-7 or 0.0000001 moles of H+/L, which is
neutrality
the pH of urine, saliva
6.3-6.6
pH of blood
neutral, pH of 7.4
Carbohydrates
sugars, starches, glycogen, and cellulose
Carbohydrates
sugars, starches, glycogen, and cellulose
Carbohydrates are divided into three major groups based on their size
monosaccharides, disaccharides, and polysaccharides
Disaccharides are formed from two monosaccharides by
dehydration synthesis
split disaccharides back into simple sugars
Hydrolysis
the largest carbohydrates, are known as complex carbohydrates; they can include hundreds of monosaccharides
Polysaccharides
The principal polysaccharide in the human body is
glycogen
glycogen is stored where
in the liver and skeletal muscles
joined by dehydration synthesis, and separated by hydrolysis
Monosaccharides
contain carbon, hydrogen, and oxygen; however, unlike carbohydrates, they do not have a 2:1 ratio of hydrogen to oxygen
Lipids
have fewer polar covalent bonds, and thus they are mostly insoluble in polar solvents such as water (they are hydrophobic)
Lipids
soluble in non-polar solvents such as chloroform or alcohol
lipids
the most plentiful lipids in the body and provide protection, insulation, and energy (both immediate and stored)
Triglycerides
structurally similar to triglycerides and are important membrane components
Phospholipids
composed of four rings of carbon atoms. Examples include dietary lipid cholesterol, and the sex hormones estrogen and testosterone
Steroids
give structure to the body, regulate processes, provide protection, help muscles to contract, transport substances, and serve as enzymes.
Proteins
Amino acids contain
carbon, hydrogen, oxygen, and nitrogen
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
The denaturation of a protein by a hostile environment causes
a loss of its characteristic shape and function
Different amino acids join together to form peptides, polypeptides, or proteins via dehydration synthesis. The bonds between the amino acids are
Peptide Bond
Catalysts in living cells are called
enzymes
speed up chemical reactions by increasing the frequency of molecule collisions, lowering the activation energy, and properly orienting colliding molecules
Enzymes
huge organic molecules that contain carbon, hydrogen, oxygen, nitrogen, and phosphorus.
Nucleic acids
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)
carries instructions from the genes in the nucleus of the cell to guide how the ribosomes assemble amino acids into proteins
Ribonucleic acid (RNA)
The basic units of nucleic acids which are composed of a nitrogenous base, a pentose sugar, and a phosphate group.
nucleotides
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
building blocks of all nucleic acids
nucleotides
huge organic molecules that contain carbon, hydrogen, oxygen, nitrogen, and phosphorus.
Nucleic acids
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)
carries instructions from the genes in the nucleus of the cell to guide how the ribosomes assemble amino acids into proteins.
Ribonucleic acid (RNA)
nucleotides, which are composed of
a nitrogenous base, a pentose sugar, and a phosphate group.
The basic units of nucleic acids
nucleotides
The basic units of nucleic acids
nucleotides
the principal energy-storing molecule in the body
adenosine triphosphate
adenosine consits of
adenine and ribose
ATP is made by
three phosphate groups connected to adenosine
When energy is liberated from ATP, it is
decomposed to adenosine diphosphate (ADP) and phosphorus (P).
manufactured from ADP and P using the energy supplied by various decomposition reactions, particularly that of glucose
ATP
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
the enzyme that catalizes hydrolysis of ATP
atpase
by addition of a water molecule, energy is liberated and leaves a molecule called
adenosine diphosphate
the energy needed to attach a phosphate group to ADP in supplied mainly by the breakdown of glucose. the process is called
cellular respiration
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.
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).
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
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.
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.
How is ATP the “energy currency” of the cell?
ATP releases energy stored in its two high-energy phosphate bonds.
Define the term acid.
When put in water, an acid is a substance that dissociates into hydrogen ions and one or more anions.
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
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.
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.
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.
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.
Three important types of lipids
a) Triglycerides ― energy storage
b) Phospholipids ― membrane structure
c) Steroids ― hormones membrane structure
List the four elements that make up about 96% of our body weight:
a) Carbon
b) Hydrogen
c) Oxygen
d) Nitrogen
What are the four chemical groups of an amino acid?
Hydrogen, Amine, Carboxyl, Side chain (R group)
what is a radioactive isotope
A radioactive isotope is an isotope that is unstable and emits radiation as it breaks down.
what is a radioactive isotope
A radioactive isotope is an isotope that is unstable and emits radiation as it breaks down.
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.
What kind of a net charge is carried by a cation?
A cation is a positively charged ion.
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.
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.
Which of the following would be the smallest in size?
Electron
Which of the following is the most abundant inorganic substance in humans?
Water
The most plentiful lipid in the human body is:
Triglyceride
The more _____________ ions are present in a solution, the more basic the solution.
Hydroxide
Which of the following elements are found in carbohydrates
Oxygen/carbon/hydrogen
What type of bonds hold water molecules together?
Covalent bonds
Which of the following is considered to be neutral on the pH scale?
Pure water
Steroids are classified as
Lipids
“Saturated fat” is saturated with
Hydrogen
The atoms of the isotopes of a particular element vary in their number of
Neutrons
Which element is needed for clotting and muscle contraction, and contributes to the hardness of teeth and bone?
Calcium