General Biology: Lessons 1-3 Overview

A comprehensive set of vocabulary flashcards covering the key terms and concepts from the notes on hierarchy of life, cell theory, cell structure, organelles, cell types, and basic histology.

Atoms

Basic particles of chemical elements (protons, neutrons, and electrons).

Molecules

Two or more atoms bonded together; examples include H2O, CO2, and C6H12O6.

Macromolecules

Very large molecules such as carbohydrates, lipids, proteins (enzymes), and nucleic acids.

Organelles

Subcellular structures within a cell, e.g., mitochondria.

Cell

The basic unit of life. Eukaryotic cells have a nucleus; prokaryotic cells do not.

Tissue

A group of cells that work together to perform a common function (e.g., skeletal muscle tissue).

Organ

A structure made of tissues that performs a specific function.

Organ System

A group of organs that work together to perform broader functions (e.g., cardiovascular system).

Organism

Any living thing that functions as an individual.

Population

A group of the same species living at the same place and time.

Community

Interacting populations in a shared environment.

Ecosystem

A community plus the non-living (abiotic) environment.

Biome

A large-scale ecosystem; e.g., tropical climates in the Philippines.

Biosphere (Ecosphere)

The worldwide sum of all ecosystems.

Hydrosphere

All planetary water systems.

Cryosphere/Triosphere

Ice component of the Earth (noted as Triosphere in the notes).

Geosphere

Rocks and minerals of the Earth.

Atmosphere

The layer of gases surrounding Earth.

Lithosphere

The solid, outer part of the Earth (land).

Earth

The only astronomical object known to harbor life.

Order (Life Property)

Organisms are highly organized, coordinated structures composed of cells.

Reproduction

The ability to produce new organisms; involves sexual and asexual modes.

Stimuli Response

Organisms respond to diverse environmental stimuli.

Growth (Life Property)

Organisms grow and develop according to genetic instructions.

Regulation

Complex regulatory mechanisms coordinate internal functions and responses to environment.

Energy Processing

All organisms use a source of energy for activities.

Homeostasis

Maintenance of stable internal conditions (temperature, pH, chemical balance).

ATP

Adenosine Triphosphate; the primary energy currency, produced mainly in mitochondria.

DNA

Deoxyribonucleic acid; genetic material containing hereditary information.

Glycosidic Bond

A type of covalent bond joining a sugar molecule to another group, such as in nucleotides.

Cell Theory - Postulates I-VI

I: All living organisms are made of cells; II: Cells are the basic units of life; III: Cells arise from pre-existing cells; IV: Hereditary information is passed from cells; V: All cells have the same basic chemical composition; VI: Energy flow occurs within cells.

Basic Cell Chemical Composition

Elements: carbon, hydrogen, oxygen, nitrogen, phosphorus, potassium (K), and sulfur.

Robert Hooke

1665 English physicist who studied cells; coined the term 'cell' from cork observations.

Antonie van Leeuwenhoek

Father of Microbiology; observed microorganisms (animalcules).

Matthias Schleiden

1838 botanist who proposed that all plant tissues are made of cells.

Theodor Schwann

1839 physiologist who proposed that all animal tissues are made of cells.

Rudolf Virchow

Proposed that new cells arise from pre-existing cells.

Prokaryotic Cell

Small, simple cells lacking a nucleus and membrane-bound organelles; DNA is circular and located in cytoplasm.

Eukaryotic Cell

Larger, more complex cells with a true nucleus and membrane-bound organelles.

Nucleus

Membrane-bound organelle containing genetic material (DNA).

Cell Membrane (Plasma Membrane)

Phospholipid bilayer that encloses the cell and regulates substance movement.

Cell Wall

Rigid layer outside the cell membrane; present in plant cells and many bacteria.

Cytoplasm

Interior of the cell between the membrane and nucleus; contains cytosol and organelles.

Mitochondria

Powerhouse of the cell; site of ATP production.

Chloroplast

Organelle in plants/algae where photosynthesis occurs; contains chlorophyll.

Ribosome

Molecular machine for protein synthesis; can be free-floating or attached to ER.

Nucleolus

Nuclear substructure where ribosomal RNA (rRNA) synthesis occurs.

Nucleopores

Pores in the nuclear envelope that regulate ribosome and RNA traffic.

Haploid (n)

Single set of chromosomes; typical of prokaryotes and gametes in meiosis.

Diploid (2n)

Two sets of chromosomes; typical of somatic cells in most organisms.

Binary Fission

Asexual reproduction in prokaryotes where a cell divides into two.

Archaea

Unicellular, prokaryotic organisms often living in extreme environments.

Phospholipid Bilayer

The double-layered membrane that makes up cell membranes.

Intracellular Space

Inside the cell.

Extracellular Space

Outside the cell.

Glucose (C6H12O6)

A simple sugar; main energy source for most organisms.

Lipids

Hydrophobic molecules such as fats and oils used for energy storage and membranes.

Hydrophobic

Water-fearing; nonpolar molecules tend to repel water.

Hydrophilic

Water-loving; polar molecules dissolve in water.

Bacteria (Peptidoglycan; LPS)

Prokaryotes; cell walls contain peptidoglycan; Gram-negative bacteria have lipopolysaccharides.

Superbug

Antibiotic-resistant bacteria.

Apoptosis

Programmed cell death; a controlled way for cells to die.

Lysosomes

Organelle with enzymes that digest waste and damaged organelles.

Glycosidic Bond

Bond connecting a sugar molecule in carbohydrates or nucleic acids.

Nitrogenous Bases (DNA)

Adenine, thymine, cytosine, guanine in DNA; pairings encode genetic information.

Chromosomes

DNA packaged with proteins in the nucleus; humans have 46 (23 pairs).

Autosomes

Non-sex chromosomes (22 pairs in humans).

Sex Chromosome

Chromosome determining sex (X and Y in humans).

Gamma of Cell Structures (Page 4 terms: Nucleus, Nucleolus, Ribosomes, Nucleopores)

Nucleus = genetic material; Nucleolus = ribosome synthesis; Ribosomes = protein synthesis; Nucleopores = gateways in the nuclear membrane.

Endoplasmic Reticulum (ER)

Rough ER has ribosomes for protein synthesis; Smooth ER synthesizes lipids.

Golgi Body

Sorting and dispatch center for materials within the cell.

Mitochondria (revisited)

Powerhouse; generates ATP via cellular respiration.

Chloroplast and Chlorophyll

Chloroplast performs photosynthesis; Chlorophyll is the pigment that captures light.

Vacuoles

Storage organelles; central vacuole in plants stores water.

Egg Cell

Largest cell in the human body; female gamete.

Sperm Cell

Smallest cell; male gamete; contains flagellum for movement.

Plasmid

Circular DNA molecule in bacteria that carries extra genes.

Reticulum (ER)

Endoplasmic reticulum; site of lipid and protein synthesis (rough and smooth).

Hypothesis of Stem Cells: Pluripotency

Cells capable of giving rise to all cell types except placenta.

Stem Cells: Unipotency

Cells capable of differentiating into only one cell type.

Embryonic Stem Cells

Primitive, undifferentiated cells from an embryo with high pluripotency.

Stem Cell Plasticity

Ability of stem cells to differentiate into multiple cell types.

Hematopoietic Stem Cells

Stem cells that give rise to all blood cells (RBCs, WBCs, etc.).

Mesenchymal Stem Cells

Stem cells that can form bones, cartilage, fat, and connective tissue.

Skin Stem Cells (Basal Layer)

Basal layer cells (keratinocytes) that renew the epidermis.

Keratinocytes

Skin cells that produce keratin and protect against toxins and pathogens.

Melanocytes

Skin cells that produce melanin, affecting pigmentation and UV protection.

Merkel Cells

Touch receptor cells in the skin linked to nerves.

Langerhans Cells

Skin immune cells involved in antigen processing.

Endothelial Cells

Cells lining blood vessels; involved in vascular function.

Epithelial Cells

Cells lining cavities and surfaces of organs; form barriers and secretion.

Dendritic Cells

Immune cells that present antigens to T cells.

Monocytes and Macrophages

Monocytes circulate in blood; macrophages engulf pathogens (phagocytosis).

Neurons

Nerve cells that transmit electrical signals; main cells of the brain and nervous system.

Neuroglial (Glial) Cells

Support cells in the nervous system (astrocytes, oligodendrocytes, microglia, etc.).

Astrocytes

Glial cells providing nutrients and support to neurons.

Oligodendrocytes

Glial cells that form the lipid-rich myelin sheath.

Ependymal Cells

Glial cells involved in producing cerebrospinal fluid.

Microglia

Glial cells that act as macrophages in the CNS.

Muscle Tissues

Skeletal (voluntary), Cardiac (heart, involuntary), and Smooth (involuntary, in organs like the digestive tract).