Bio and Basic Chemistry 2A and 2B

What is chemistry’s role in physiology?

Governs all biological functions via chemical reactions.

What is matter?

Anything with mass and space.

What is weight?

Mass plus gravity.

States of matter?

Solid (def shape/volume), Liquid (def volume), Gas (changeable both).

What is energy?

Capacity to do work or move matter.

Does energy have mass/space?

No.

Kinetic energy?

Energy in action.

Potential energy?

Stored energy.

4 forms of energy?

Chemical, electrical, mechanical, radiant.

What happens in energy conversion?

Converted forms; some lost as heat.

What are elements?

Substances that can’t be broken down by ordinary means.

Four elements = 96% body?

C, O, H, N.

What are atoms?

Smallest particle of element, retain properties.

What do chemical symbols represent?

Elements (e.g., O = oxygen, Na = sodium).

3 subatomic particles?

Protons (+, 1 amu), Neutrons (0, 1 amu), Electrons (-, 0 amu).

Planetary vs orbital model?

Planetary = fixed orbits; Orbital = probability cloud.

Atomic number?

Number of protons.

Mass number?

Protons + neutrons.

Isotopes?

Same element, diff neutrons.

Atomic weight?

Average mass of isotopes.

Radioisotopes?

Unstable, emit radiation; used in medicine, can damage tissue.

Molecule?

2+ atoms bonded (e.g., O2).

Compound?

2+ different atoms (e.g., H2O).

Mixture?

Physical combo of components.

3 types of mixtures?

Solutions, colloids, suspensions.

Solution?

Homogeneous, particles don’t settle (e.g., saline).

Colloid?

Heterogeneous, cloudy, particles don’t settle (e.g., cytosol).

Suspension?

Heterogeneous, large particles settle (e.g., blood cells).

3 ways to express concentration?

Percent, mg/dL, molarity (M).

Difference

mixtures vs compounds?

What determines chemical bonding?

Valence shell electrons.

Octet rule?

Atoms stable with 8 valence electrons.

Noble gases reactivity?

Inert (full shells).

How do atoms get stable?

Gain, lose, or share electrons.

Ionic bond?

Transfer electrons → ions (e.g., NaCl).

Covalent bond?

Share electrons.

Nonpolar covalent bond?

Equal sharing.

Polar covalent bond?

Unequal sharing (partial charges).

Hydrogen bond?

Weak attraction H ↔ electronegative atom; stabilizes proteins/DNA.

What do chemical reactions do?

Form, break, rearrange bonds.

Reactants vs products?

Reactants = starting, Products = results.

Synthesis reaction?

Atoms/molecules combine.

Decomposition reaction?

Break molecule into smaller pieces.

Exchange reaction?

Both synthesis + decomposition.

Redox reaction?

Electron transfer; reduction = gain, oxidation = loss.

Exergonic reaction?

Release energy; products lower energy.

Endergonic reaction?

Absorb energy; products higher energy.

Reversibility of reactions?

Theoretically reversible; biologically often not.

4 factors affecting reaction rate?

Temperature ↑, concentration ↑, particle size ↓, catalysts.

What are enzymes?

Biological catalysts.

What is biochemistry?

Study of chemical composition and reactions of living matter.

Two main types of compounds in the body?

Inorganic (water, salts, acids, bases) and Organic (carbs, fats, proteins, nucleic acids).

Do inorganic compounds usually contain carbon?

No.

Do organic compounds contain carbon?

Yes, usually large and covalently bonded.

What % of cell volume is water?

60–80%.

5 important properties of water?

High heat capacity, high heat of vaporization, polar solvent, reactivity, cushioning.

Why is high heat capacity important?

Prevents sudden temperature changes.

Why is high heat of vaporization important?

Provides cooling (sweating).

Why is water a good solvent?

Polar; dissolves and dissociates substances.

Example of water in chemical reactions?

Hydrolysis and dehydration synthesis.

How does water cushion organs?

Protects from trauma (e.g., CSF cushions brain).

What happens when salts dissolve in water?

Dissociate into ions.

What does NaCl dissociate into?

Na+ and Cl−.

What are cations?

Positively charged ions (e.g., Na+, K+, Ca2+).

What are anions?

Negatively charged ions (e.g., Cl−, PO43−).

What are electrolytes?

Ions in solution that conduct electricity.

Roles of electrolytes?

Nerve impulses, muscle contraction, fluid balance.

Examples of common body salts?

NaCl, CaCO3, KCl, calcium phosphates.

What is an acid?

Proton donor; releases H+ in solution.

What is a base?

Proton acceptor; releases OH− in solution.

Examples of acids in body?

HCl, acetic acid, carbonic acid.

Examples of bases in body?

Bicarbonate (HCO3−), ammonia (NH3).

Why are acids and bases also electrolytes?

They ionize and dissociate in water.

Why is acid-base balance important?

Maintains homeostasis (pH balance).

Role of water in body?

Solvent, temp regulation, chemical reactions, cushioning.

Role of NaCl?

Electrolyte balance, nerve transmission.

Role of HCl?

Stomach acid, digestion.

Role of bicarbonate (HCO3−)?

Buffering blood pH.

Role of calcium phosphate?

Bone and teeth structure.

Define biochemistry.

Study of chemical processes in living organisms.

Define inorganic compound.

Compound usually without carbon.

Define electrolyte.

Conducts electricity in water.

Define acid.

Proton donor (releases H+).

Define base.

Proton acceptor (releases OH−).

Define salt.

Ionic compound from acid-base neutralization.