Essential Biology Laboratory Investigations
Cell Observation with a Microscope
Experiment Aim
To observe, draw, and label cells using a microscope, such as onion epidermal cells or cheek cells.
Required Equipment
- Light Microscope
- Glass Slide
- Cover Slip
- Specimen (Onion or Cheek cells)
- Iodine Solution
- Pipette
- Tweezers
- Paper Towel
Experimental Procedure
- Peel a thin layer of onion skin and place it on a clean slide.
- Add a few drops of iodine stain (to make the structures visible).
- Carefully place a cover slip on top, avoiding air bubbles.
- Place the slide on
Matter, Atoms, and Biomolecules: Foundations of Biology
Fundamentals of Matter and Atoms
Matter
Matter is defined as the amount of mass that occupies a space.
The Atom and Its Subatomic Particles
An atom is considered the indivisible part of matter and is composed of three primary subatomic particles:
- Protons (H+): Subatomic particles with a positive charge.
- Neutrons (n): Subatomic particles with a neutral charge.
- Electrons (e-): Subatomic particles with a negative charge.
Isotopes and Atomic Properties
An isotope is an atom that contains a greater number of
Read MoreChemical Reaction Kinetics: Rates, Mechanisms, and Factors
Reaction Rate: Definition
Reaction Rate: The measure of how quickly reactants are consumed or how quickly products are formed in a chemical reaction.
Rate Law Equation
The Rate Law Equation describes the relationship between the rate at which a chemical process occurs and the concentrations of the reactants.
The rate constant (k) depends on the specific reaction and the temperature at which it takes place.
Reaction Order Explained
Reaction Order: The sum of the exponents to which reactant concentrations
Read MoreWater: Structure, Properties, and Global Impact
The Water Molecule
Each water molecule consists of two hydrogen (H) atoms and one oxygen (O) atom. The water molecule has a bent shape, with the H-O-H bond angle being approximately 105°. The two O-H bonds are polar covalent, which makes the entire molecule polar.
Hydrogen Bonding
Hydrogen bonds form when a hydrogen atom, already bonded to an electronegative atom (like oxygen), is attracted to another electronegative atom in a different molecule. These crucial intermolecular links are responsible
Read MorePeriodic Table of Elements: History and Classification
The Periodic Table of Elements
The periodic table of elements is an organizational system that distributes various chemical elements based on specific criteria and characteristics. Its development is usually attributed to Dmitri Mendeleev, who ordered elements based on the periodic variation of chemical properties. Julius Lothar Meyer, working separately, developed a similar system based on the physical properties of atoms.
Discovery of Elements
While some elements such as gold (Au), silver (Ag), copper
Read MoreEssential Organic Chemistry: Reactions & Functional Groups
Carboxylic Acids: Properties & Reactions
- Oxidation: Primary alcohols or aldehydes
- Hydrolysis of Esters: Acidic or basic mechanisms
- Hell-Volhard-Zelinsky (HVZ) Reaction: α-halogenation via PBr3 and Br2
Key Characteristics of Carboxylic Acids
- Polar and acidic nature
- Form strong hydrogen bonds
- Undergo nucleophilic substitution reactions
Acid Derivatives: Synthesis & Reactivity
Includes acid chlorides, esters, amides, and anhydrides.
Synthesis Methods
- From acids using SOCl2 (for acid chlorides)
- From acids