Introduction to Matter and Biochemistry

Matter
- Anything that has mass and occupies space.
- Everything in the human body is made of matter.
Atom
- Smallest unit of matter.
- Building blocks of all body structures.
Atomic Particles
- Proton
- Positive charge ( $+$ ).
- Located in the nucleus.
- Neutron
- No charge (neutral).
- Located in the nucleus.
- Electron
- Negative charge ( $-$ ).
- Moves around the nucleus.
Element
- Pure substance.
- A specific type of atom.
- Examples: Oxygen, Carbon, Sodium, Calcium.
Molecule
- Consists of $2$ or more atoms bonded together.
- Atoms may be the same or different.
- Examples: $O_2$ , $H_2$ , $H_2O$ .
Compound
- Consists of $2$ or more different elements bonded together.
- Examples: $H_2O$ , $CO_2$ , $NaCl$ .

Formation of Bonds
- Atoms stick together by forming chemical bonds.
- Atoms become more stable through this process.
Ionic Bond
- Forms when one atom transfers one or more electrons to another atom.
Ion
- An ion is an atom that has a positive or negative electrical charge because it has gained or lost electrons.
- Positive Ion (Cation): If an atom loses an electron, it now has more protons than electrons (more $+$ than $-$ ). Example: $Na \rightarrow Na^+$ . Sodium loses one electron to become a positive ion.
- Negative Ion (Anion): If an atom gains an electron, it has more electrons than protons and becomes negative.

Electrolytes
- A substance that forms ions when dissolved in water.
- These ions conduct electricity and help the body function normally.
Specific Electrolyte Functions
- Sodium ( $Na^+$ )
- Helps regulate fluid balanced.
- Helps nerves send signals.
- Helps muscles contract.
- Potassium ( $K^+$ )
- Heart rhythm.
- Muscle contraction.
- Nerve conduction.

Covalent Bonds
- This type of bond is formed when two atoms share electrons.
- Sharing electrons makes them stable and creates a strong chemical bond.
- Covalent bonds do not usually break in water.
- Covalent bonds form most of the body's organic compounds, including:
- Carbon ( $C$ )
- Hydrogen ( $H$ )
- Oxygen ( $O$ )
- Nitrogen ( $N$ )
Hydrogen Bonds
- Weak attraction between molecules.
- Helps hold the structure of water and protein.
- These bonds gain strength as more hydrogen bonds join.
Inorganic Compounds: Water
- Essential to life.
- Found inside and around each cell.
- Functions of Water:
- Dissolves substances (solvent).
- Transport of nutrients, cells, and waste.
- Temperature regulation.
- Good for blood circulation.
- Nursing Considerations:
- Monitor hydration status (too little or too much water).
- Deviations (too much/little) can disrupt electrolyte balanced.

Acids
- Release hydrogen ions ( $H^+$ ) in water.
- Have a pH less than $7$ .
Bases
- Release hydroxide ions ( $OH^-$ ) or accept hydrogen ions.
- Have a pH greater than $7$ .
Salt
- Formed when an acid and a base react.
- Separate into ions when dissolved in water.
Acid-Base Imbalances
- Can be harmful to the body.
- The body attempts to correct imbalances through compensatory mechanisms.
- Organs for Blood pH Maintenance:
- Respiratory system.
- Urinary system (kidneys).
- Buffers
- Chemicals in the blood that help maintain a stable pH.

Blood pH Classification
- Normal Blood pH: $7.35 - 7.45$ .
- Acidosis: High acidity signified by a low blood pH (< 7.35).
- Alkalosis: High alkalinity signified by a high blood pH (> 7.45).
Organic Chemistry: Macromolecules
- Carbohydrates
- Main source of energy.
- Glucose is the body's main energy source.
- Lipids
- Store energy.
- Provide insulation and protection.
- Protein
- Build and repair tissues.
- Made of amino acids.
- Involved in regulation.
- Nucleic Acids
- DNA and RNA.
- Store and transmit genetic information.
- Direct protein synthesis.