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Atomic Structure, Elements of the Body, Chemical Bonding, and Properties of Water

Atomic Structure

  • Focus on PowerPoints for quizzes and exams.
  • Understanding chemical concepts is crucial for understanding physiological processes to understand how atoms interact.

Matter

  • Matter is anything that occupies space.

  • Exists in three forms: solid (ice), liquid (water), and gas (moisture).

  • Water's properties make life possible.

Atoms

  • Atoms are the smallest particles exhibiting chemical properties of an element.

  • Elements include carbon, oxygen, nitrogen, sodium, and potassium.

  • Each element has unique atoms.

Elements in the Human Body

  • Elements occur naturally and are essential for various properties in the body.

  • Six major elements make up over 98% of the human body (focus on four):

    • Oxygen (O)
    • Carbon (C): Basis for macromolecules.
    • Hydrogen (H): Component of water (H_2O).
    • Nitrogen (N)
    • Calcium (Ca): Important for diet.
    • Phosphorus (P): Needed for ATP (adenosine triphosphate) and bone growth.

  • Minor/Trace Elements:

    • Sulfur (S)
    • Potassium (K)
    • Sodium (Na)
    • Chlorine (Cl)
    • Magnesium (Mg)
    • Iron (Fe)

Iron (Fe)

  • Essential for blood formation.

  • Found in erythrocytes (red blood cells) within the hemoglobin pigment.

  • Without iron, no hemoglobin is present, leading to anemia.

  • Sources: Organ meat (liver), eggplant.

  • Eggplant oxidizes (turns brown) due to iron content.

Iodine

  • Important for thyroid gland function; needed to produce thyroxine.

  • Deficiency can lead to goiter (enlarged thyroid gland) and affects metabolic rate.

  • Source: Iodized salt.

Atomic Structure

  • Atoms have subatomic particles: protons, neutrons, and electrons.

  • Shell model: Atoms have a nucleus containing protons (positively charged) and neutrons (no charge).

  • Electrons (negatively charged) orbit the nucleus in shells.

Subatomic Particles

  • Protons: In the nucleus, positively charged.

  • Neutrons: In the nucleus, no charge.

  • Electrons: Orbit around the nucleus in shells, negatively charged.

  • The number of protons, neutrons, and electrons differ for each element.

Periodic Table

  • Displays elements with atomic number (number of protons), symbol, and atomic mass (mass of protons and neutrons).

  • Each element has a unique symbol (e.g., H for hydrogen, O for oxygen).

Shell Model

  • Atoms have shells of electrons surrounding the nucleus.

  • Innermost shell holds two electrons.

  • Second shell can hold up to eight electrons.

  • First shell must be filled before moving to the next.

  • Outer shell typically holds a maximum of eight electrons (octet rule).

  • No empty shells between filled shells.

Isotopes

  • Different atoms of the same element with the same number of protons and electrons but different numbers of neutrons.

  • Exhibit identical chemical characteristics.

  • Example: Carbon exists as C-12, C-13, and C-14.

Importance

  • Radioisotopes are used in medical imaging to identify tumors (e.g., in the thyroid gland).

Chemical Stability and Octet Rule

  • Periodic table organized by electrons in the outer shell.

  • Column eight elements have a full valence shell of eight electrons = noble gasses.

  • Atoms are stable with eight electrons in the outer shell.

Octet Rule

  • Elements lose, gain, or share electrons to obtain a complete outer shell (eight electrons) for stability.

  • Atoms interact to become stable via giving, gaining, or sharing electrons.
    Analogy:

  • Atom A (7 electrons) interacts with Atom B (8 electrons) to achieve stability.

Chemical Bonding

Ions and Ionic Compounds

Sodium Chloride (NaCl)

  • Sodium (Na) loses one electron, chlorine (Cl) gains one electron.

  • Chemical compound: Two atoms come together and share or exchange electrons.

  • Ionic bond: Losing or gaining an electron (e.g., sodium chloride).

  • Ionic compounds: Structures composed of ions held together.

Ions

  • Groups of atoms with a positive or negative charge.

  • Produced by loss or gain of electrons.

Physiological Functions

  • Sodium (Na+): Electrical signals in neurons.

  • Calcium (Ca2+): Blood clotting and muscle contraction.

  • Chlorine (Cl-): Hydrochloric acid in the stomach for digestion.

  • Ions are formed by ionization (gaining or losing electrons).

Common Cations (Positively Charged)

  • Sodium, potassium, calcium, magnesium, and hydrogen play vital roles.

  • Calcium: Bone and teeth strength, muscle contraction, exocytosis, and blood clotting.

  • Magnesium required for ATP production.

Common Anions (Negatively Charged)

  • Chloride ions, bicarbonate (buffering), phosphate (ATP molecules) play important roles.

Cations vs. Anions

  • Cation: Loses an electron, becomes positively charged.

  • Anion: Gains an electron, becomes negatively charged.

  • Positive and negative charges attract (e.g., sodium and chlorine forming sodium chloride).

  • Ionic compounds generally exist in solids (e.g., table salt).

Molecular Compounds

  • Stable association between two or more atoms of elements held together by chemical bonds.

  • Written as molecular formulas (e.g., C6H{12}O_6 for glucose).

  • Examples: Water (H2O), carbon dioxide (CO2), and glucose.

Isomers

  • Molecules with the same molecular formula but different arrangements (e.g., glucose, galactose, fructose).

  • Isomers have different chemical properties.

Covalent Bonds

  • Most abundant and strongest bonds in the body.
    *Formes by the sharing of electrons among atoms to become stable forming covalent bonds
  • Formed by sharing electrons between atoms.

Properties

Example: Simplest covalent bond formation occurs between two hydrogen atoms.

**Outer Shell Sharing:

  • When two electrons are shared (a pair), it forms a double bond; depending on the number of electrodes, Single, double and triple bonds are formed; there is no losing or gaining involved.**

Most Common Elements in Covalent Bonds:

  • Carbon, hydrogen, oxygen, and nitrogen.

Atoms in a covalent may not share electrons equally

  • Nonpolar: Equal sharing of electrons.

  • Polar: Unequal sharing of electrons.

Hydrogen Bonds

  • Weakest of all bonds; easy to make and break.

  • Weak intermolecular attractions between partially positive and partially negative atoms of polar molecules.

  • Individually weak, collectively strong (e.g., surface tension in water).

  • Important in maintaining the shape of complex molecules (e.g., DNA double helix).

Molecular Structure of Water

  • Polar molecule composed of one oxygen atom bonded to two hydrogen atoms.

  • Can form four hydrogen bonds with adjacent molecules.

  • Central to water's properties, making life possible.

Water exist in three phases depending on temperature.**

  • Gas - vapor
  • Liquid form- major component of our body
  • Solid- ice* Properties includes cohension, tension, addhesion.*
    Water molecules help to prevent the lungs from collapsing, it's a mixture of lipids and the proetins. (like a baby and a soap bubble floating on the water and doesn't pop due to air and surface tension)

Important properties of Water

  • The high heat of visicocity have made life water, without it we would not exist.*

  • Temperature is kinetic energy within the solution.* High and low temperatures we die.*
    High heat of voporization helps the body in many ways.

  • Solvent vs Solute** *Water is refered to as *universial solvent becuase the electrolytes will intereact with plan*

  • **What is formed when water dissociates? H_2 O spontaenously is disassossiated to form ions.
    *** Acids dissociate into hydrogen ions in one or more anions, leads to positive ions.
    Hydrocloric is an acid, is sour and disassosiates fast*
    Acids donate in the water*
    Hydroxides take the proton acceptor and decreases the concentration of ions in in in the solution.
    PH measures the log of the ions and the ph scale is zero to fourteen. The PH Scale is always 0 to 14
    PH
    Zero to fourteen scale
    Neutral, solution is equa to hydroxyl ions. So pure water is neutral
    Water is the measure to whether it's acidic, auqaline or base, you mix two sentences
    Hyrdroxy ions, if you are girls in the room and boys what occurs depending on the amounts of them.
    What are th ethree categories of WATER mixtures?