Biochemistry and Intro to Chemistry - Lecture Notes Review

Biochemistry Foundations

The transcript introduces biochemistry as the study of the tiny ingredients in the body, connecting chemistry to biology.
Chemistry definition: the study of matter and reactions.
Biochemistry combines these ideas to explain how the body's small components interact and function.

One LEGO piece represents a pattern (an atom type).
A molecule is two or more atoms bonded together.
The analogy uses colored LEGOs to illustrate different atom types; the idea is that a molecule is built from different atoms in a bond.
Important clarification (from the lecture tone): a molecule can include identical atoms as well as different ones (e.g.,
there are molecules like
ext{O}2 or ext{H}2 ext{O}). A compound is formed from two or more elements.
The transcript mentions HCO as bicarbonate; the correct chemical form is bicarbonate ion: ext{HCO}_3^-.
This section emphasizes breaking things down into basic building blocks: atoms → molecules → compounds.

Ionic bonding:
- Forms when electrons are transferred from one atom to another.
- Creates ions with opposite charges; these ions attract each other.
- Often described as an electrostatic attraction between cations and anions.
- The metaphor: magnets that attract due to opposite charges.
Covalent bonding:
- Involves sharing electrons between atoms.
- The transcript uses the idea of atoms "holding hands" to illustrate sharing.
Important correction from the lecture notes/teacher feedback:
- Opposite charges attract; like charges repel. So, two negatives do not attract each other and two positives do not attract each other.
- In real biology, many interactions are ionic or hydrogen bonds, which can be weaker in aqueous environments, but covalent bonds are typically strong bonds within molecules.
Takeaway: Ionic bonds involve electron transfer; covalent bonds involve electron sharing; both are essential for structure and function in biomolecules.

Acids are substances that release hydrogen ions in solution: ext{acid}
ightarrow ext{H}^+ ext{ + conjugate base}.
pH scale basics:
- Acidic region: 0 \, \le \; pH \; \le \; 6.9
- Neutral: pH = 7
- Basic/Alkaline: 7.1 \le pH \le 14
Alkalosis: condition of too much base in the body; clinical symptoms can include muscle cramps and irritability; relates to pH regulation in physiology.
The lecture references a chart of pH values (to be posted to you); this chart is used to relate pH to physiological states.
Bicarbonate and buffering:
- Bicarbonate as a buffer helps regulate blood pH; form noted in the transcript as ext{HCO}_3^- (bicarbonate ion).
Real-world relevance: maintaining proper pH is crucial for enzyme activity, metabolic processes, and overall homeostasis.

Calcium is involved in:
- Muscle contractions
- Nerve signaling
- Concentration-related roles in physiology (linking to homeostasis concepts like maintaining proper ion balance and signaling cascades)
Homeostasis (the transcript references the idea of maintaining stable internal conditions): pH, ion concentrations, and other biochemical balances are kept within narrow ranges for proper function.
Concentration concept discussed:
- Concentration refers to the amount of solute in a given amount of solution.
- The transcript mentions measuring milligrams to milliliters as a common way to express concentration in biological contexts.
- Common concentration expressions include:
- C = \dfrac{m}{V} (mass concentration, e.g., mg/mL)
- C = \dfrac{n}{V} (molar concentration, e.g., mol/L or M), where n is moles and V is volume.
The idea is that calcium and other ions participate in signaling and contraction through precise concentrations in bodily fluids.

Concentration is the amount of solute per unit volume:
- Generic form: C = \dfrac{\text{solute amount}}{\text{solution volume}}
Common units:
- Mass-based: \text{mg/mL}
- Molar: \text{mol/L} = \text{M}
Why it matters:
- Proper concentrations ensure enzymes function, signaling pathways proceed correctly, and tissues maintain integrity.
The transcript’s practical note: measuring using milligrams and milliliters is common when preparing solutions or dosing in physiological contexts.

Proteins have a key role in rebuilding tissue:
- They support the skin and connective tissue (among other tissues).
- They contribute to structure (collagen, elastin, etc.), repair, and maintenance of tissues.
The transcript emphasizes protein’s rebuilding function in the context of tissue maintenance and healing.

Bicarbonate is listed as ext{HCO}_3^- and is a critical buffering agent in blood.
Buffers help resist changes in pH when acids or bases are added, maintaining homeostasis in bodily fluids.
Practical relevance: Buffer systems are essential for maintaining enzyme activity and metabolic stability during digestion, respiration, and other physiological processes.

The notes illustrate how chemistry concepts underpin bodily functions: bonding, electron transfer, acid-base balance, ion concentrations, and protein functions.
Understanding these basics helps explain physiologic phenomena such as muscle contraction, nerve signaling, blood pH regulation, and tissue repair.
Ethical/philosophical/practical implications (implicit): accurate interpretation of pH and buffering is essential in medical settings (e.g., diagnosing acid-base disturbances, guiding therapies), and misinterpretation can lead to incorrect clinical decisions.
Suggested study approach reflected in the transcript: writing out and organizing concepts (paraphrase and structured notes) to improve understanding.