UPCAT Science Reviewer Notes

Solutions

• Solvent: The substance that dissolves the solute in a solution.
• Water as a Solvent: Effective due to its polarity and small molecular size.
• Saturated Solution: A solution that cannot dissolve any more solute at a given temperature.
• Miscible Liquids: Liquids that can form a solution when mixed (e.g., ethanol and water).
• Supersaturated Solution: Requires specific conditions, not simply adding more solute or solvent.
• Physical Change:
  • Example: Sugar dissolving in water.
  • Not a physical change: Boiling an egg (chemical change).
• Chemical Change: Results in substances with different properties.
• Law of Definite Proportions: A compound always contains the same elements in the same proportion by mass (e.g., Heptane is always 84% carbon and 16% hydrogen).

Atomic Structure

• Mass Number: The sum of protons and neutrons in an atom's nucleus. $(\text{Mass Number} = \text{Protons} + \text{Neutrons})$

Chemical Reactions

• Rate of Reaction: Increased by higher temperature and higher reactant concentrations.
• Activation Energy: The energy needed to start a chemical reaction; supplied by a match when lighting a candle.

Thermodynamics

• Ice water warms up faster than ice cold water on a warm day

Motion and Mechanics

• Inertia: An object's tendency to stay at rest unless acted upon by a force.
• Constant Velocity: Achieved when the applied force equals the opposing forces.
• Acceleration: Caused by unbalanced forces.
• Work Done: $(\text{Work} = \text{Force} \times \text{Distance})$
• Power: $(\text{Power} = \frac{\text{Work}}{\text{Time}})$

Waves and Sound

• Frequency of Motion: Inversely related to the mass of the block on the end of the spring.

Optics

• Color Absorption: A red gemstone absorbs most wavelengths except red, which it reflects.
• Refraction: Light moving from water to air at 90° is not refracted.

Heat Transfer

• Heat Transfer Processes: Radiation and convection.

States of Matter

• Density: $(\text{Density} = \frac{\text{Mass}}{\text{Volume}})$
• Phase Changes: The graph shows the substance completely turns into gas from 0-16 mins. The substance is solid from 0-2 mins.

Mixtures

• Suspension vs. Colloid: Suspensions have larger particles that settle over time and can be filtered.

Gases

• Molecular Speed and Kinetic Energy: At the same temperature, lighter molecules (e.g., hydrogen) have higher average speeds but the same kinetic energy as heavier molecules (e.g., oxygen).

Acids and Bases

• Acids: Form hydronium ions ($H_3O^+$) in water.
• Acids in Cooking: Marinades use acids to tenderize meat.

Chemistry

• Distillation: Separates components based on differences in boiling points.
• Conservation of Mass: Mass is neither created nor destroyed in a chemical reaction.
• Balancing Equations: e.g., $AlCl<em>3 + 3NaOH \rightarrow Al(OH)</em>3 + 3NaCl$
• Alkenes: Hydrocarbons containing one or more double bonds.
• Endothermic Process: Absorbs heat from the surroundings; has a positive sign.

Evolution

• Darwin's Theory: Supported by fossil evidence, island species, and artificial selection.
• Analogous Structures: Structures with similar functions but different evolutionary origins (e.g., the wing of a bird and a bat wing).

Biology

• Levels of Organization: Cell is the smallest/lowest level.
• Properties of Life: Includes responding to stimuli, reproducing, and regulating internal environment.

Pendulums

• Kinetic Energy: Maximum at the lowest point (C) of the swing.
• Speed: Minimum at the highest points (A and E) of the swing.

Antibiotic Resistance

• Natural Selection: Antibiotic resistance evolves because antibiotics create an environment where resistant bacteria flourish.

Cell Structure

• Capsule: A slippery outer covering that protects bacteria from phagocytosis.
• Eukaryotic vs. Prokaryotic Cells: Eukaryotic cells have mitochondria; prokaryotic cells have simpler cell walls.
• Protoplasts: Cells without a cell wall.

Ecology

• Niche: Realized niche is narrower than the fundamental niche.
• Sporozoa: Protozoa with no means of locomotion.

Physiology

• Vertebrate Skeleton: Living tissue that grows, protects organs, and provides attachment points for muscles.