Essential Biology Terms and Concepts for Students
Key Biological Terms
Abiotic: Non-living.
Aerobic: Biological processes occurring in the presence of oxygen.
Anaerobic: Biological processes occurring without oxygen.
Anabolism: Metabolic reactions synthesizing larger molecules from smaller ones, requiring energy.
DNA: Molecule containing genetic information, responsible for protein production and hereditary transmission.
Alleles: Alternative forms of a gene.
Amino Acids: Building blocks of proteins.
Antibody: Plasma protein synthesized by the immune system, binding specifically to antigens.
Antigen: Foreign molecule stimulating antibody production.
Golgi Apparatus: Cell organelle involved in processing and packaging proteins.
ATP: Adenosine triphosphate, the main energy currency of the cell.
Bacteria: Main class of prokaryotes.
Catabolism: Metabolic processes breaking down larger molecules into smaller ones, releasing energy.
Catalyst: Substance speeding up a chemical reaction.
Cell: Basic structural and functional unit of living organisms.
Zygote: Diploid cell resulting from the union of two haploid gametes.
Cytoskeleton: Protein structures providing internal cell support.
Cytosol: Fluid part of the cytoplasm where metabolic reactions occur.
Cytoplasm: Viscous contents of the cell, excluding the nucleus.
Krebs Cycle: Set of reactions in mitochondrial respiration, degrading acetic acid to carbon dioxide and releasing energy.
Complement: Group of plasma proteins causing lysis of foreign cells.
Chromosome: Structure in the nucleus containing DNA and genes.
Chromatin: Complex of DNA and proteins in eukaryotic cells.
Diploid: Cell with two sets of homologous chromosomes.
Disaccharides: Carbohydrates composed of two monosaccharides.
Enzyme: Protein biocatalyst.
Eukaryote: Cell with a defined nucleus.
Phagocytosis: Ingestion and destruction of germs by phagocytic cells.
Gamete: Haploid reproductive cell.
Gene: Unit of heredity.
Genome: Complete set of genetic elements.
Carbohydrates: Energy source and reserve.
Glucose: Monosaccharide, main energy source.
Glycogen: Polysaccharide, energy storage in animal cells.
Gluconeogenesis: Synthesis of glucose from non-carbohydrate sources.
Glycolysis: Catabolic pathway for glucose degradation.
Haploid: Cell with a single set of chromosomes.
Hydrolysis: Breaking down a chemical compound by adding water.
Mendelian Inheritance: Heredity linked to non-sex chromosomes.
Sex-linked Inheritance: Genetic inheritance through sex chromosomes (X or Y).
Immunoglobulins: IgA, IgG, IgM, IgD, IgE.
Immune: Specific defensive reaction to a substance or infectious agent.
More Key Biological Terms
Interferon: Chemical inhibiting viral spread.
Lysosome: Vesicle with digestive enzymes.
B Lymphocytes: Produce antibodies, humoral immunity.
T Lymphocytes: Cell-mediated immunity.
Macrophages: Large phagocytic cells.
Plasma Membrane: Cell membrane surrounding the cytoplasm.
Meiosis: Cell division producing haploid cells.
Mitosis: Eukaryotic cell division.
Metabolism: Set of chemical reactions in the cell.
Mitochondria: Organelles producing cellular energy (ATP).
Nucleus: Organelle containing chromosomes and DNA.
Nucleolus: Structure in the nucleus where ribosomal RNA is synthesized.
Proteins: Organic compounds formed by amino acids.
Prokaryotes: Cells lacking a defined nucleus.
Endoplasmic Reticulum: Organelle involved in protein synthesis and lipid metabolism.
Rough Endoplasmic Reticulum: Synthesizes, stores, and transports proteins, containing ribosomes.
Smooth Endoplasmic Reticulum: Synthesizes, stores, and transports lipids, cholesterol, and steroids, lacking ribosomes.
Ribosomes: Structures involved in protein synthesis.
Tissue: Group of similar cells working together.
Transcription: Synthesis of RNA from DNA.
Translation: Protein synthesis from RNA.
Transaminase: Enzyme indicating liver or kidney damage.
Virus: Nucleic acid and protein structure reproducing inside cells.
Immune System Components
Immune System: Mechanisms protecting the body from infection.
I. Nonspecific Defense Mechanisms
1. Physical Barriers:
Skin and Mucous Membranes: Prevent microorganism entry.
Washing: Tears, coughing, urination, bowel movements.
2. Chemical Barriers:
Acidity: Skin, stomach, vagina.
Lysozyme: Saliva, tears (breaks bacterial walls).
3. Biological Barriers:
Normal Flora: Inhibitory microorganisms.
Natural Resistance: Species-specific immunity.
4. Nonspecific Immunity:
Innate, natural immunity, independent of immune memory.
- Inflammation, natural killer (NK) cells.
- Interferon: Proteins inhibiting viral replication.
- Complement: Plasma proteins controlling infections.
II. Specific Immunity
B Lymphocytes: Produce antibodies.
T Lymphocytes: Cell-mediated immunity (helper T cells, cytotoxic T cells).