What is Chemistry concerned with?
Chemistry is concerned with the composition of substances and how they change in chemical reactions
All anatomical structures are?
chemicals
All physiological processes are based on?
chemical reactions
What does biochem help explain?
Helps explain physiological and disease processes
Why is chemistry studied in A/P?
�Chemistry is concerned with composition of substances and how they change in chemical reactions.
�Human body, food, and medications are all composed of chemicals.
�All anatomical structures are chemicals, and all physiological processes are based on chem
Matter
Anything that takes up space and has mass. Matter is composed of elements. Solids, liquids, and gases are matter.
Elements
Simplest types of matter with certain chemical properties. There are 98 naturally occurring elements.
Atoms
Smallest particles of an element that have properties of that element
Different elements are required by the body in ?
different amounts
Bulk Elements
required by the body in large amounts: CHONPS: make up +25% of body weight
Trace Elements
required by the body in small amounts: Fe, I
Ultratrace Elements
required by the body in very
minute amounts - As
Atomic Structure
Atoms: Composed of subatomic particles:
Proton: Carries a single positive charge
Neutron: Carries no electrical charge
Electron: Carries a single negative charge
Nucleus:
Central part of atom
Composed of protons and neutrons
Electrons move around the nucl
Characteristic of Electron and Electron Change
Extremely small particle within a atom; almost no weight; carries a negative electrical charge and is in constant motion around an atomic nucleus
CHANGE: becomes an ion then
- Particle, formed from an atom, that is electrically charged bc it has gained or
Characteristics of Proton and Proton Change
Characteristics: Relatively large particle w/n an atom; carries a positive electrical charge, found w/n atomic nucleus
CHANGE: molecule then
- Particle formed by the chem union of two or more atoms
Atomic Number
�Number of protons in the nucleus of an atom of a specific element
�Each element has a unique atomic number
�Number of protons is equal to the number of electrons in the atom; atoms are electrically neutral
Atomic Weight
�The number of protons plus the number of neutrons in one atom
�Electrons do not contribute to the weight of the atom because they are so light
Isotopes
Isotopes are atoms with the same atomic numbers but with different atomic weights.
Isotopes contain different numbers of neutrons, but same number of protons & electrons.
Example: Oxygen often forms isotopes (O16, O17, and O18, with numbers representing a
All atoms of a certain element have the same?
atomic #
Radioactive Isotopes
Radioactive isotopes are unstable, releasing energy or atomic fragments (atomic radiation) until they gain stability; some are used to detect and treat disease.
For any element, the atomic weight is often considered the?
average of the atomic weights of all of its isotopes.
How can radioactive isotopes reveal physiology?
Radioactive iodine-131 can be used to destroy cancerous thyroid gland tissue. This is very effective, because the thyroid gland is the only part of the body that actively transports and metabolizes iodine.
Radioactive isotopes have many medical uses: dete
Ionizing Radiation
Radiation (alpha, beta, and gamma) is called ionizing radiation, because its energy can remove electrons from atoms, resulting in the formation of ions. The free electrons can damage nearby atoms.
Ionizing radiation sources include X rays, naturally occur
Alpha Radiation
consists of particles from atomic nuclei, each of which includes two protons and two neutrons that move slowly and cannot easily penetrate matter
Beta Radiation
consists of much smaller particles (electrons) that travel faster and more deeply penetrate matter
Gamma Radiation
form of energy similar to X-Ray and is most penetrating form of atomic radiation
Molecule
Particle formed when two or more atoms chemically combine
Compound
Particle formed when two or more atoms of different elements chemically combine
Molecular Formulas
Depict the elements present and the number of each atom present in the molecule
H2 = a molecule of hydrogen
C6H12O6 = a molecule of glucose
H2O = a molecule of water
Describe the formation of water
Molecules of hydrogen or
oxygen form when 2 identical
atoms combine chemically. (H-H) and (O-O)
When 2 atoms of hydrogen
combine with 1 atom of oxygen,
the compound water is formed. (H20)
When do chemical bonds form?
Chem bonds form when atoms combine with other atoms. They result from interactions between the electrons of the atoms.
Electron Shells or Energy Shells
Electrons of an atom occupy regions of space called electron shells (energy shells), which circle the nucleus
Rules of Electron Shells
For atoms with atomic numbers of 18 or less, the following rules apply:
� The first shell can hold up to 2 electrons
� The second shell can hold up to 8 electrons
� The third shell can hold up to 8 electrons
Lower energy shells/inner orbits are filled fir
Octet Rule
Except for the first shell, 8 electrons are required to fill the shells in most of the atoms important in living organisms so that the outermost shell is completely filled and achieves a more stable structure like the noble gases
Inert
Atoms like HE, whose outermost electron shells are filled, already have stable structures and are chemically inactive or inert (they cannot form chemical bonds).
Ion
�An atom that gains or loses electrons to become stable
�An electrically charged atom
Cation
�A positively charged ion
�Formed when an atom loses electrons
Anion
�A negatively charged ion
�Formed when an atom gains electrons
Ionic Bonds
Formed when electrons are
transferred from one atom to another atom
The attraction between a
cation and an anion forms a very strong bond between the ions, called an ionic bond.
Covalent Bonds
Strong chemical bonds, formed between atoms that share electrons
Ex1. Two atoms of hydrogen (H) have combined to form a hydrogen molecule (H2). Both atoms in the molecule become stable.
Ex2. Hydrogen molecules (H2) often combine with oxygen (O2) molecules
Structural Formulas
show how atoms bond and are arranged in various molecules.
- One line between atoms means that 1 pair of electrons are being shared (forming single bonds), while two lines indicate that 2 pairs are being shared (forming double bonds).
Polar Molecules
�Molecules with a slightly negative end and a slightly positive end
�Results from unequal sharing of electrons in covalent bonds
�Water is an important polar molecule
- In this water molecule, the
O nucleus pulls the
electrons more strongly than the H nuc
Hydrogen Bond
�A weak attraction between the slightly positive (H) end of one polar molecule and the slightly negative (N or O) end of another polar molecule
�Formed between adjacent water molecules
�Important for protein and nucleic acid structure
Why are H bonds imp?
�Important for protein and nucleic acid structure
Chemical Reactions
Chemical reactions occur when chemical bonds form or break between atoms, ions, or molecules.
Ex. dissociation of NaCl in water to form Na+ and Cl- ions.
Reactants
Reactants are the starting materials of a chemical reaction: the atoms, ions, or molecules.
Products
Products are substances formed at the end of the chemical reaction.
Types of Chemical Reactions
Synthesis, Decomposition, Exchange, Reversible Reactions
Chemical Reaction: Synthesis Reaction
more complex chemical structure is formed
A+ B --> AB
Chemical Reaction: Decomposition Reaction
chemical bonds are broken to form a simpler chemical structure
AB --> A+ B
Chemical Reaction: Exchange Reaction
chemical bonds are broken and new bonds are formed
AB + CD --> AD + BC
Chemical Reaction: Reversible Reaction
the products can change back to the reactants
A + B <--> AB
Catalysts
are molecules that influence the rates (not the direction) of chem rxn but are not consumed in the process
Dissaciate
When ionically bound substances are placed in water, the ions are attracted to the pos and neg ends of the water molecules and tend to leave each other, or dissociate
Electrolytes:
Substances that release ions in water. The solution can conduct an electric current, so it is called an electrolyte.
NaCl --> Na+ + Cl-
Acids
Electrolytes that dissociate to release hydrogen ions in water
HCl --> H+ + Cl-
Bases
Substances that release ions that can combine with hydrogen ions
NaOH --> Na+ + OH-
Salts
Electrolytes formed by the reaction between an acid and a base
HCl + NaOH --> H20 + NaCl
What happens when ionically bonded substances are placed in water?
When an ionically bonded substance is put into water, the charged ions are attracted to the slightly charged ends of the polar water molecules.
This dissociates the substance, and the ions become surrounded by water molecules. The substance is now called
Concentrations of acids and bases affect?
Concentrations of acids and bases affect chemical reactions in living organisms.
What is H+ ion concentration measured in?
H+ ion concentration is measured in g/L of body fluid.
pH scale
The pH scale is used as shorthand for H+ ion concentration; it is based on the number of decimal places in the concentration
�pH scale runs from 0 - 14; each number represents a tenfold difference in H+ ion concentration
�Acids have a pH <7, and bases hav
Interpreting H+ Ion Concentration and pH Scale
�If H+ ion concentration = 0.01 g/L, the pH = 2
�If H+ ion concentration = 0.000000001 g/L, the pH =9
Correlation between Hydrogen Ion Concentration and pH Scale
The higher the H+
concentration, the
lower the pH, and
the higher the
acidity.
The lower the H+
concentration, the
higher the pH, and
the lower the acidity
(which corresponds
to higher alkalinity).
What does the pH indicate toward?
Indicates the concentration of hydrogen ions in a solution
Neutral pH
A pH of 7 indicates equal concentrations of H+ and OH-. This is the pH of water.
Acidic pH
A pH of <7 indicates a greater concentration of H+ than OH-
Basic (alkaline) pH
A pH >7 indicates a higher concentration of OH- than H+
What is the normal range of blood pH?
Normal range of blood pH is 7.35 - 7.45
Acidosis
Acidosis occurs when blood pH drops to 7.0 - 7.3
�Makes a person feel disoriented, fatigued: Alkalosis
�Caused by vomiting of alkaline intestinal contents, diabetes, lung disease with impaired CO2 exhalation
Alkalosis
Alkalosis occurs when blood pH rises to 7.5 - 7.8 - Alkalemia
�Makes a person feel dizzy and agitated
�Caused by high altitude breathing, vomiting of acidic stomach contents, high fever, taking excess antacids
�Homeostatic mechanisms help regulate pH
� Bu
What are buffers and how do they relate to alkalosis?
Buffers are chemicals which act to resist pH
changes; bind and release H+ ions to regulate pH
Chemical Constituents of Cells: Organic v Inorganic Molecules
Organic molecules:
�Contain C and H
�Depending on the type, they will dissolve in either water or organic liquids
�Water-soluble organic compounds do not release ions, and are non-electrolytes
�Carbohydrates, proteins, lipids, and nucleic acids
Inorganic
Organic Molecules
�Contain C and H
�Depending on the type, they will dissolve in either water or organic liquids
�Water-soluble organic compounds do not release ions, and are non-electrolytes
�Carbohydrates, proteins, lipids, and nucleic acids
Inorganic Molecules
�Generally do not contain C and H
�Usually dissolve in water and dissociate, forming ions, and are electrolytes
�Water, oxygen, carbon dioxide, and inorganic salts
Inorganic Substances
Water, Oxygen (O2), Carbon Dioxide, Inorganic Salts
Water: Inorganic Substance
Most abundant compound in living material
Two-thirds of the weight of an adult human
Major component of all body fluids
Medium for most metabolic reactions
Important role in transporting chemicals in the body
Absorbs and transports heat
Water balance exis
Solvent / Solute / Solution Define
A substance in which other substances dissolve is a solent. Water is an imp solvent bc many other substances readily dissolve in it. A substances dissolved in a solvent, like water, is called a solute. The combo of a solvent and any other solvent and any
Water Balance
Body reg gains and loses water, but it must be present in the correct {} in the extracellular fluid, to aintain homeostasis. Such condition where gains and losses of water are equal is called water balance
Oxygen (O2): Inorganic Substance
Used by organelles to release energy from nutrients in order to drive cell's metabolic activities
Necessary for survival
Carbon Dioxide: Inorganic Substances
�Waste product released during metabolic reactions
�Must be removed from the body through exhaling
Inorganic Salts: Inorganic Substances
�Abundant in body fluids
�Sources of necessary ions (Na+, Cl-, K+, Ca+2, etc.)
�Play important roles in metabolism
�Help control H2O concentration, pH, blood clotting, nerve
and muscle processes
�Electrolyte balance exists when gains equal losses
Organic Substances: Carbohydrates
A. Main source of cellular energy:
�Supply materials to build cell structures
�Water-soluble
�Contain C, H, and O
�Ratio of H to O close to 2:1 (C6H12O6 = glucose)
B> Size classification of carbohydrates:
�Monosaccharides (single sugars): glucose, fructos
What is the main source of cellular energy? (organic substance)?
CARBOHYDRATES: �Supply materials to build cell structures
�Water-soluble
�Contain C, H, and O
�Ratio of H to O close to 2:1 (C6H12O6 = glucose)
Size Classification of Carbs
Size classification of carbohydrates:
�Monosaccharides (single sugars): glucose, fructose
�Disaccharides (double sugars): sucrose, lactose
�Polysaccharides (complex carbohydrates: starch, glycogen, cellulose)
Glucose have straight chain or carbon atoms, r
Lipids: Organic Substances
�Insoluble in water, but soluble in organic solvents
�Include triglycerides (fats), phospholipids, steroids
�Important component of cell membranes, and have several functions in cells
What are the most abundant lipids and what are their uses?
Most abundant lipids are triglycerides (fats):
a. Used for cellular energy
b. Contain more energy per gram than carbohydrates
c. Contain C, H, and O, but less O than carbohydrates
d. Consist of 1 molecule of glycerol and 3 fatty acids
Two Types of Fatty Acids
saturated and unsaturated
Saturated: Lipids
Saturated fatty acids have only single carbon-carbon bonds. Most are solid at room temperature, and of animal origin.
Unsaturated: Lipids
Unsaturated fatty acids have one or more carbon-carbon double bond. Most are liquid at room temperature, and are of plant origin.
A triglyceride is composed of
1 glycerol molecule and 3 fatty acids.
Phospholipids: Lipids
�Consist of 1 glycerol, 2 fatty acids, and 1 phosphate
�Have hydrophilic Glycerol portion and hydrophobic fatty acid ends
�Major component of cell membranes
Steroids: Lipids
�4 connected rings of carbon
�Widely distributed in the body, various functions
�Component of cell membranes
�Used to synthesize adrenal and sex hormones
�Cholesterol is the main steroid in the body
Types of Lipids
triglycerides, phospholipids, steroids
Proteins: Organic Substances
Proteins are used as structural materials, energy source, hormones, receptors, enzymes, antibodies.
Proteins consist of building blocks called amino acids.
An amino acid contains an amino (-NH2) group, a carboxyl (COOH) group, and a unique R (side chain)
What are amino acids consisted of?
An amino acid contains an amino (-NH2) group, a carboxyl (COOH) group, and a unique R (side chain) group.
How are amino acids bound to each other/linked?
Amino acids are bound to each other by peptide bonds
Where do peptide bonds form?
Peptide bonds form between the amino group of one amino acid, and the carboxyl group of the adjacent amino acid.
4 Levels of Protein Structure
Primary: Amino acid sequence
Secondary: Pleated or twisted structure formed by hydrogen bonding between nonadjacent amino acids
Tertiary: Unique 3-dimensional folded shape of the protein
Quaternary: Structure formed by some proteins, when 2 or more polype
Primary: Protein Structure
Amino acid sequence
Secondary: Protein Structure
Pleated or twisted
structure formed by hydrogen
bonding between nonadjacent
amino acids
Tertiary: Protein Structure
Unique 3-dimensional
folded shape of the protein
Quaternary: Protein Structure
Structure formed by
some proteins, when 2 or more
polypeptide chains are connected
to become 1 protein
Nucleic Acids: Organic Substances
Nucleic acids carry genetic code (DNA) or aid in protein synthesis (RNA).
Nucleic acids encode amino acid sequences of proteins.
Building blocks are called nucleotides, which consist of a sugar (S), a phosphate group (P), and an organic base (B).
-DNA, RN
DNA: Nucleic Acids
DNA (Deoxyribonucleic acid): a double chain of nucleotides
�Stores the genetic code
�Contains the sugar deoxyribose
�Structure�double helix
�Composed of nucleotides
RNA: Nucleic Acids
RNA (Ribonucleic acid): a single chain of nucleotides
�Interacts with DNA to conduct protein synthesis
�Contains the sugar ribose
�Structure�single strand
�Composed of nucleotides
Two major types of nucleic acids?
DNA RNA
Computerized Tomography (CT) imaging:
�Used to visualize internal anatomy
�Uses X-ray emitting device to create 3-dimensional image of soft tissues
�Differentiates tissues with slightly different densities, tumors
Positron Emission Tomography (PET) imaging:
�Uses radioactive isotopes that emit positrons (unusual positively charge electrons) to detect biochemical activity
�Used to detect various brain disorders, blood flow, normal brain physiology
Cohesion and Adhesion and importance to plants
Adhesion: water molecules stick to other substance sticks to xylem to help to fight gravity
Cohesion Water molecules stick together to help the plant stay upright
When frozen, water molecules are set into a ?
Lattice
Water Solid v Liquid
The water molecules are less dense in ice form than in liquid form. Water expand when frozen and becomes less dense when it is frozen than liquids water
Polar Molecules Another Name
Hydrophilic
Nonpolar Molecules Another Name
Hydrophobic
What property do atoms of polar molecules have that helps make the molecules stay polar?
Highly Electronegative - electron w a strong pull in a covalent bond + an unequal charge will form
What distinguishes a NP molecule from a P molecule?
NP has fewer amts of CHON
Hydrolysis
Hydrolysis is the opposite to condensation. A large molecule is split into smaller sections by breaking a bond, adding -H to one section and -OH to the other.
- The products are simpler substances. Since it involves the addition of water, this explains wh
Condensation
Condensation is a chemical process by which 2 molecules are joined together to make a larger, more complex, molecule, with the loss of water.
- It is the basis for the synthesis of all the important biological macromolecules (carbohydrates, proteins, lipi
What are two important factors in drug delivery and in movements of substances throughout the body?
Water solubility and lipid solubility