ELS_GR11 MAD_2ND QUARTER REVIEWER

Page 1: Introduction to Life Science

Overview

• Earth and Life Science topics covered include:

  • Introduction to Life Science

  • Cell Theory, Parts, Functions, and Transport

  • Cell Cycle

  • DNA, RNA, Central Dogma

  • Photosynthesis

  • Cell Respiration

Biology

• Definition: Study of structures, functions, and relationships of living organisms with their environment.

Hierarchy of Life

• Cell: Basic unit of life.

• Tissue: Group of specialized cells working together for a specific function.

• Organ System: Collection of organs performing specific functions.

• Organism: A living thing that carries out all life functions.

Primordial Soup Theory (Oparin)

• Life began from a mixture of inorganic molecules (methane, nitrogen, ammonia, etc.).

• Energy from the sun fueled chemical reactions that formed complex molecules leading to life.

Branches of Biology

• Various fields exploring living organisms and their interactions with the environment.

Page 2: Theories of Life Origin

Miller-Urey Experiment

• Simulated ancient Earth conditions; produced organic molecules from inorganic substances.

Abiogenesis

• Description: Spontaneous generation of life from non-life through energy-induced interactions of organic molecules.

• Historically supported by Ancient Egyptians, Aristotle, John Needham.

Biogenesis

• Definition: Life arises from pre-existing life.

• Key scientists:

  • Francesco Redi: Experimented with jar conditions to test spontaneous generation.

  • Lazzaro Spallanzani: Extended Needham's experiment to kill microorganisms.

  • Louis Pasteur: Enhanced Spallanzani's findings, affirming biogenesis.

Creationism

• Belief in a supernatural being's role in creating life and the universe.

• Philippine Version: Malakas at Maganda, a creation myth similar to Adam and Eve.

The Theory of Evolution

• Living organisms evolve over time, adapting their structures and functions in response to environmental changes.

Page 3: Comparative Anatomy and Evolution

Structural Comparisons

• Homologous Structures: Same origin, different function.

• Analogous Structures: Different origin, similar function.

Notable Figures

• George-Louis Buffon: Contributed to understanding of thermophiles.

• Charles Darwin: Introduced "Survival of the Fittest".

• Jean Baptiste Lamarck: Proposed that organism traits develop through use (Lamarckism).

Panspermia/Cosmozoic Theory

• Life on Earth potentially started from extraterrestrial origins; lacks scientific evidence.

Page 4: Cell Types and Structure

Prokaryotes vs. Eukaryotes

• Prokaryotes: Single-celled organisms without a defined nucleus; abundant on Earth.

• Eukaryotes: Multicellular organisms with a defined nucleus containing DNA.

Types of Eukaryotic Cells

• Plants: Cellulose cell wall, chloroplasts, vacuoles.

• Animals: No cell wall, may have flagella.

• Protists: Cell wall but lack differentiated tissues.

• Fungi: Chitin cell wall; heterotrophs.

Page 5: Structure and Function of Cells

Basic Cell Structures

1. Cell Membrane:

   • Selective barrier regulating material passage.

2. Cytoplasm:

   • Gel-like substance for biochemical reactions and metabolic support.

3. Cell Nucleus:

   • Control center housing DNA and facilitating ribosome synthesis.

Protein Synthesis

• Ribosomes: Synthesize proteins using mRNA.

Endoplasmic Reticulum (ER)

• Network of membranes:

  • Rough ER: Ribosomes present; protein synthesis/modification.

  • Smooth ER: Lipid synthesis, carbohydrate metabolism, detoxification.

Page 6: Energy and Cellular Digestion

Golgi Apparatus

• Processes, packages proteins/lipids from ER; maintains internal balance.

Mitochondria

• Known as Powerhouse of the Cell; generates energy via cellular respiration.

Endosymbiotic Theory

• Eukaryotic cells evolved from engulfed prokaryotic cells.

Chloroplasts

• Exclusive to plant cells; responsible for photosynthesis.

Types of Plastids

• Chloroplasts: Photosynthesis.

• Chromoplasts: Plant pigments.

• Leucoplasts: Non-pigmented, starch storage (

Cellular Digestion

• Lysosomes: Digest unwanted materials.

• Peroxisomes: Degrade toxins, regulating metabolism.

Page 7: Cell Support and Movement

Cytoskeleton

• Provides support and enables movement; crucial for cell stability.

Flagella/Cilia

• Flagella: Elongated structures for protist motility.

• Cilia: Shorter structures aiding in fluid movement over cell surfaces.

Storage and Transport

• Vesicles/Endosomes: Transport materials between organelles.

Differences in Cell Types

• Animal Cells: Smaller, lack cell walls/chloroplasts.

• Plant Cells: Rigid cell walls, contain chloroplasts.

Page 8: Cell Transport Mechanisms

Cell Membrane Functions

• Separates cell from environment, regulates material flow, maintains homeostasis.

Types of Cell Transport

• Active Transport: Requires energy (e.g., endocytosis).

• Passive Transport: No energy needed (e.g., diffusion).

Cell Tonicity

• Refers to water movement affecting cell volume.

Endocytosis/Exocytosis

• Endocytosis: Bulk transport into the cell.

• Exocytosis: Bulk transport out of the cell.

Page 9: Cell Cycle and Disorders

Phases of Cell Cycle

• G1: Growth phase.

• S: DNA copying.

• G2: Preparation for division.

• M: Mitosis.

Genetic Conditions

• Klinefelter Syndrome (47, XXY): Additional X chromosome leads to physical characteristics.

• Turner Syndrome (45, XO): Absence of X chromosome.

• Cri-Du-Chat Syndrome (46, 5p-): Partial loss of chromosome 5.

• Down Syndrome (47, 21+): Trisomy 21 with distinctive eye folds.

• Edward Syndrome (47, 18+): Trisomy with severe developmental issues.

• Patau Syndrome (47, 13+): Similar to Edward syndrome, early mortality.

Page 10: DNA and Genetic Information

DNA Structure

• Definition: Molecule carrying genetic instructions, discovered through inheritance studies.

• Double Helix: Twisted structure with bases (A, C, G, T).

Nucleotide Composition

• Pyrimidines: Cytosine and Thymine.

• Purines: Adenine and Guanine.

DNA Replication

• Process of duplicating DNA before cell division.

mRNA and Protein Synthesis

• mRNA: Transmits genetic information from DNA to ribosomes.

• Translation: Protein synthesis based on mRNA template.

Page 11: Photosynthesis and Cellular Respiration

Photosynthesis Overview

• Converts light energy to chemical energy in glucose; requires sunlight, carbon dioxide, and water.

• Occurs in mesophyll cells of leaves.

Light Reactions

• Light-dependent reactions capturing sunlight energy.

Cellular Respiration

• Converts sugars to usable energy; involves Glycolysis, Krebs Cycle, and Electron Transport Chain.