Matthayom Sueksa 3 Science Curriculum

UNIT Genetics and Heredity

1.1 DNA and Genes

• DNA (Deoxyribonucleic Acid) and genes are related to the genetic information of living organisms.
• DNA is a molecule that carries the genetic information for the development of living organisms.
• Genes are segments of DNA that determine the characteristics of a living organism.
• The structure of DNA is like a twisted ladder called a double helix with two long strands of nucleotides coiled around each other.
• Nucleotides are the building blocks of DNA, consisting of a sugar molecule, a phosphate group, and nitrogenous bases.
• There are four types of nitrogenous bases: adenine (A), guanine (G), cytosine (C), and thymine (T).
• The two DNA strands are held together by hydrogen bonds between the nitrogenous bases, with adenine (A) always pairing with thymine (T) and cytosine (C) always pairing with guanine (G).
• The functions of DNA include genetic information storage, protein synthesis, genetic inheritance, gene regulation, DNA replication, DNA repair, and evolutionary history.
• Gene expression is the process by which the information encoded in a gene is used to produce a functional gene product, such as a protein or RNA molecule.
• The process of gene expression includes transcription, mRNA processing, translation, and protein folding and function.

1.2 Cell Cycle and Chromosomes

• Chromosomes are thread-like structures found within the nucleus of a cell, composed of DNA, proteins, and other associated molecules.

• The structure of chromosomes includes DNA, histones, chromatin, sister chromatids, centromere, telomeres, and chromosomal arms (short arm or "p arm" and long arm or "q arm").

• There are 46 chromosomes in human cells, arranged into 23 pairs.

• The main phases of a cell cycle include interphase, mitosis, and cytokinesis, with stages including prophase, metaphase, anaphase, telophase, and cytokinesis.### Types of Chromosomes

• There are two main types of chromosomes: Autosomes ( Autosomal Chromosomes) and Sex Chromosomes (Allosomes)

  • Autosomes determine most traits and characteristics of an individual
  • Sex Chromosomes determine the sex of an individual and are responsible for sexual development

Human Chromosomes

• Humans have a total of 46 chromosomes, organized into 23 pairs
  • 22 pairs of autosomes labeled as chromosome 1 through 22
  • 1 pair of sex chromosomes, called X and Y chromosomes
  • Females have two X chromosomes (XX), while males have one X and one Y chromosome (XY)

Cell Cycle and Chromosomes

• The cell cycle refers to the series of events that take place in a cell as it grows, replicates its DNA, and divides into two daughter cells
  • The main phases of the cell cycle are Interphase and M Phase
  • Interphase has three subphases: G1 Phase (Gap 1 Phase), S Phase (Synthesis Phase), and G2 Phase (Gap 2 Phase)
  • M Phase (Mitotic Phase) consists of two main processes: Mitosis and Cytokinesis

Mitosis

• Mitosis is the process of cell division that results in two identical daughter cells, each with the same number of chromosomes as the parent cell
  • There are four stages of Mitosis: Prophase, Metaphase, Anaphase, and Telophase

Meiosis

• Meiosis is a specialized type of cell division that occurs in sexually reproducing organisms
  • Meiosis consists of two main stages: Meiosis I and Meiosis II
  • Meiosis I has four stages: Prophase I, Metaphase I, Anaphase I, and Telophase I
  • Meiosis II has four stages: Prophase II, Metaphase II, Anaphase II, and Telophase II

Inheritance of Traits

• Traits are passed from parents to offspring through genes
  • Mendelian Inheritance Pattern is a way of predicting the inheritance of traits
  • Punnett Square is a tool used to predict the possible genotypes and phenotypes of offspring based on the genotypes of the parents

Genetic Disorders

• Genetic disorders are caused by mutations in one or a few genes
  • Some genetic disorders are caused by abnormal numbers of chromosomes
  • Examples of genetic disorders include Marfan syndrome, sickle cell anemia, hemophilia A, and Down syndrome

Acids and Bases

• Acids produce hydrogen ions, while Bases accept hydrogen ions

  • pH scale is used to measure the concentration of hydrogen ions in a substance
  • Acid-base indicators are substances that change color in response to changes in pH
  • pH and pOH of a substance can be calculated using various formulas### Properties of Acids and Bases

• Acids are substances that produce H+ ions in aqueous solutions (Arrhenius definition) or donate protons (Bronsted Lowry definition).

• Bases are substances that produce OH- ions in aqueous solutions (Arrhenius definition) or accept protons (Bronsted Lowry definition).

• Acids have a sour taste, no slippery feel, and corrode metals, while bases have a bitter taste, slippery feel, and don't corrode metals.

• pH of acids is less than 7, while pH of bases is greater than 7.

Applications of Acids and Bases

• Acids are found in food and beverages (e.g., citrus fruits, vinegar), cleaning products (e.g., acetic acid, phosphoric acid), personal care products (e.g., salicylic acid, lactic acid), and medical and pharmaceuticals (e.g., ascorbic acid, hydrochloric acid).
• Bases are found in baking and cooking (e.g., baking soda, baking powder), agriculture and gardening (e.g., calcium bicarbonate), food preservation (e.g., sodium hydroxide), and antacid medicine (e.g., aluminum hydroxide gel).

Acids and Bases Indicators

• Types of indicators: natural (e.g., litmus paper, beetroot, turmeric, red cabbage, China Rose), synthetic (e.g., phenolphthalein, methyl orange), and olfactory (e.g., onion, vanilla extract).
• Examples of indicators and their color changes:
  • Litmus paper: blue turns red (acid), red turns blue (base)
  • Beetroot: turns to purple (acid), turns to yellow (base)
  • Turmeric: remains yellow (acid), turns to red (base)
  • Red cabbage: turns to pink or red (acid), turns to blue, green, or yellow (base)
  • China Rose: turns to magenta (acid), turns to green (base)
  • Phenolphthalein: remains colorless (acid), turns to pink (base)
  • Methyl orange: remains orange (acid), turns to yellow (base)
  • Onion: retains smell (acid), loses smell (base)
  • Vanilla extract: retains smell (acid), loses smell (base)

pH and pOH

• pH is a measure of the power of hydrogen or potential of hydrogen, used to determine whether a solution is acidic, basic, or neutral.
• pOH is a measure of the hydroxide ion concentration.
• The relationship between pH and pOH is: pH + pOH = 14.

Organic Compounds

• Organic compounds are compounds that contain carbon atoms bonded to other atoms, most commonly hydrogen.
• All living things are made up of organic compounds.

Hydrocarbons

• Hydrocarbons are organic compounds composed solely of hydrogen and carbon atoms.
• Physical properties: insoluble in water, increase in boiling point with increasing molecular weight, and flammable.
• Classification: aliphatic (linear or branched arrangement of carbon atoms) and aromatic (cyclic structures with alternating double bonds).
• Examples: alkanes (e.g., methane, ethane, butane), alkenes (e.g., ethene, propene, heptene), and alkynes (e.g., ethyne, propyne).
• Reactions: combustion, halogenation, addition, and substitution.

Alcohols, Carboxylic Acids, and Esters

• Alcohols are organic compounds that contain a hydroxyl group (-OH) bonded to a carbon atom.
• Physical properties: soluble in water, higher boiling point, and distinctive odor.
• Reactions: oxidation, esterification, dehydration, and substitution.
• Carboxylic acids are organic compounds that contain a carboxyl group (-COOH) attached to a carbon atom.
• Physical properties: tend to have higher boiling point, strong and pungent odor, and weak acidic properties.
• Reactions: acid-base, esterification, reduction, and decarboxylation.
• Esters are organic compounds that contain a carbonyl group (C=O) bonded to an oxygen atom (O) and an alkyl or aryl group (R).
• Physical properties: lower boiling points, fruity or floral odor, and generally soluble in organic solvents.
• Reactions: hydrolysis, transesterification, and reduction.

Polymers

• Polymers are large molecules made up of smaller repeating units called monomers.
• Types of polymers: natural, synthetic, linear, branched, crosslinked, addition, and condensation.
• Properties: mechanical (strength, elasticity, ductility, brittleness, and toughness), thermal (melting point, glass transition temperature), electrical (conductivity, dielectric properties), and optical (transparency, refractive index).
• Uses and applications: packaging materials, textile and clothing, automotive components, medical devices, construction materials, electronics, and adhesive and coatings.

Biochemistry

• Biochemistry deals with the structures, bonding, functions, and interactions of biological macromolecules, such as proteins, carbohydrates, lipids, and nucleic acids.
• Biomolecules: carbohydrates, proteins, lipids, and nucleic acids.
• Composition and functions of each type of biomolecule:
  • Carbohydrates: composed of carbon, hydrogen, and oxygen, function as energy source and structural components.
  • Proteins: composed of carbon, hydrogen, oxygen, and nitrogen, function as enzymes, hormones, and structural components.
  • Lipids: composed of carbon, hydrogen, and oxygen, function as energy storage and structural components.
  • Nucleic acids: composed of carbon, hydrogen, oxygen, nitrogen, and phosphorus, function as genetic material and_blueprint for life.