Comprehensive Notes: Biology and the Chemistry of Life
Biology and Its Branches
- Biology is a natural science concerned with the study of life and living organisms, including their structure, function, growth, evolution, distribution, and taxonomy.
- Biology generally recognizes the cell as the basic unit of life, genes as the basic unit of heredity, and evolution as the engine that propels the synthesis and creation of new species.
- The term biology is derived from the Greek word bios, "life" and the suffix -logia, "study of."
Biological Organization
- Biological Organization refers to the hierarchical arrangement of living things from the smallest units to the whole system.
- Slide content (illustrative sequence): Atom → Molecule/Compound → Organelle → (Levels of Organization) → Cell → Tissue → Organ → Organ System → Organism.
- Expanded Levels (as listed): Populations → Organisms → Organ Systems → Organs → Tissues → Cells.
- Note: These levels describe increasing complexity from microscopic to population-level organization.
- The structure applies to humans as well as other organisms.
Levels of Biological Organization
- Smallest unit: Atom
- Next: Molecule or Compound
- Then: Organelle
- Then: Cell
- Then: Tissue
- Then: Organ
- Then: Organ System
- Then: Organism
- Then: Populations
- Then: Organisms (plural level)
- Then: Organ Systems (reiterated level)
- Then: Organs
- Then: Tissues
- Then: Cells
Cells
- A cell is the most basic unit of structure.
Tissues
- General concept: groups of similar cells performing a common function; specific examples in the slide are garbled in the transcript.
Organs
- Structures composed of two or more tissues working together to perform a specific function.
Organ Systems
- Groups of organs that cooperate to carry out major physiological functions (e.g., digestive system, circulatory system).
Organisms
- Individual living beings that can carry out all life processes.
Populations
- Groups of individuals of the same species living in a defined area.
Classification of Living Things
- What is classification? Classification is the grouping of living organisms according to similar structures and functions.
- Early classification systems: Aristotle grouped animals according to the way they moved.
- The modern classification system (developed by Carolus Linnaeus) consists of 7 levels: Kingdom, Phylum, Class, Order, Family, Genus, Species.
FIVE KINGDOMS (historical perspective)
- Monera: single-celled organisms without a nucleus. Bacteria make up this kingdom. More forms of bacteria than any other organism on Earth. Some bacteria are beneficial (e.g., those in yogurt); others can cause illness.
- Fungi: usually motionless organisms that absorb nutrients for survival. Includes mushrooms, molds, and yeasts.
- Protists: mostly single-celled organisms with a nucleus; usually live in water. Some protists move, others stay in one place. Examples: some algae, paramecium, and amoeba.
- Plants: contain chlorophyll and perform photosynthesis (convert energy from sunlight into food). Cell walls are cellulose. Fixed in one place. Divided into two groups: flowering/fruit-producing plants and those that don’t produce flowers or fruits (includes garden flowers, agricultural crops, grasses, shrubs, ferns, mosses, conifers).
- Animals: complex, multicellular organisms with nervous systems; subdivided into vertebrates and invertebrates; include mammals, amphibians, reptiles, birds, and fish.
- Note: There are now six kingdoms. The five-kingdom model existed around 1969 and grouped all bacteria with the others; the modern system recognizes additional complexity.
Taxonomic Example (Kingdom Animalia; some taxa shown)
- Kingdom Animalia → Phylum Chordata → Class Aves → Order Strigiformes → Family Strigidae → Genus Bubo → Species Bubo virginianus
- This example illustrates hierarchical taxonomy used to classify organisms.
Characteristics of Living Things
1) Made of Cells
- Examples: Nucleus, Red Blood cells, Onion skin epidermal cells, Human cheek cells.
2) Grows and develops - Includes: increase in cell size and/or number; development, aging, death; Differentiation (cell specialization for a certain job).
3) Obtains & uses Energy
4) Reproduces
5) Responds to the Environment - a) Movement (internal or external)
- b) Irritability (ability to respond to a stimulus)
Branches of Biology
- Biology is the study of life and concerns all living things; many branches focus on different groups or aspects of life.
ZOOLOGY
- Zoology is the study of animals. A person who studies Zoology is a Zoologist.
BOTANY
- Botany is the study of plants. A person who studies Botany is a Botanist.
CYTOLOGY
- Cytology is the study of cells.
ECOLOGY
- Ecology studies the relationships of living things with each other and their environment.
- Also ecology includes pollution issues (air and water).
CENETICS (Genetics)
- Genetics is the study of how features are passed to offspring from their parents.
ANATOMY
- Anatomy is the study of the inner organs of the body (e.g., kidney, heart, liver).
MICROBIOLOGY
- Microbiology is the study of microscopic life (e.g., bacteria).
- Typical bacteria: pilus, cytoplasm, bacterial flagellum, membrane, capsule, cell wall, ribosomes, DNA, plasma (often listed as plasmid).
TAXONOMY
- Taxonomy is the study of the classification of living organisms. Classification is made into groups of organisms.
LORNITHOLOGY
- Ornithology is the study of birds.
ENTOMOLOGY
- Entomology is the study of insects (e.g., mosquitoes) and arachnids (e.g., spiders).
PARASITHOLOGY
- Parasithology is the study of parasites; parasites are harmful organisms for living things.
BACTERIOLOGY
- Bacteriology is the study of bacteria.
- Bacterial shapes: coccus (spherical), bacillus/rod (cylindrical), spirillum (spiral).
MYCOLOGY
- Mycology is the study of fungi.
VIROLOGY
- Virology is the study of viruses.
PHYSIOLOGY
- Physiology is concerned with the function of tissue, organs, and systems.
MORPHOLOGY
- Morphology is concerned with the phenotype (appearance) of living things.
EMBRYOLOGY
Embryology studies developmental patterns from zygote to birth.
Additional subfields noted in slides: Aerobiology, Agriculture, Arachnology, Astrobiology (exobiology/exopaleontology/bioastronomy), Biochemistry, Bioengineering, Biogeography, Bioinformatics, Biomathematics (mathematical biology), Biomechanics, Biomedical research, Bio musicology, Biophysics, Cell biology, Conservation biology, Cryobiology, Developmental biology, Environmental biology, Epidemiology, Epigenetics, Ethology, Evolutionary biology, Biotechnology, Building biology.
The Chemistry of Life
- The Chemistry of Life explores how chemistry underpins biological processes.
WHY SHOULD WE STUDY CHEMISTRY IN BIOLOGY?
- Life depends on chemistry! When you eat food or inhale oxygen, your body uses these materials in chemical reactions to stay alive.
- Living things are built from chemical compounds, just as buildings are built from bricks, steel, glass, and wood.
- An understanding of building materials is analogous to understanding biological materials; the same logic applies to geneticists, ecologists, zoologists, botanists, biologists, etc.
Atoms and the History of the Atom
- The study of chemistry begins with the basic unit of matter: the Atom.
- History: Greeks first explained chemical reactions.
- 400 BC: thought that all matter was composed of Fire, Earth, Water, and Air.
- Democritus coined the term "atomos", meaning indivisible.
Structure of the Atom
- Atoms are composed of 3 main subatomic particles: Protons (+), Neutrons, Electrons (-).
- Visual representation (simplified): electron (-) ; proton (+) ; neutron (0).
- Protons and neutrons are located in the nucleus; strong forces bind them to form the nucleus; both particles have about the same mass.
- Electrons are negatively charged and have about 1/1840 the mass of a proton; they are in constant motion around the nucleus.
- Atoms have equal numbers of electrons and protons; because these subatomic particles have equal but opposite charges, atoms are neutral; charge neutrality is represented by