Biology Three domains: Bacteria, Archaea,
and Eukarya.
Created by: its_nikkii • Eukarya includes Kingdoms:
• Biology is the study of life. Plantae, Animalia, and Fungi.
• Characteristics of life: metabolism, • Protists are also Eukaryotes.
reproduction, growth, movement, • Bacteria and Archaea are
responsiveness, and complex prokaryotes.
organization. • All evolved from a universal
ancestor.
Scientific method:
Cytology: The Study of Cells
• Observation of phenomena to
formulate testable and falsifiable • Cell Theory: All living things are
hypotheses. composed of cells and come from
• Testing hypotheses, collecting data, cells.
and statistical analysis. • Cell size: Small to maximize the
ratio of surface area to volume.
Evolution
Cell (plasma) membrane:
• Evolution is the concept that all
organisms are related by common • Composed of a fluid-like
ancestry. It's the unifying theme in phospholipid bilayer, proteins,
biology. cholesterol, and glycoproteins.
• Natural selection: A mechanism for Cell wall:
evolution based on the survival of
the best-adapted offspring. • Outside of the cell membrane in
▪ Individuals sexually reproduce, some organisms.
creating many offspring. • Composed of carbohydrates (e.g.,
▪ Offspring show variations based on cellulose for plants; chitin for fungi)
genetic differences. or carbohydrate derivatives (e.g.,
▪ Individuals with adaptations survive peptidoglycan for bacteria).
to reproductive age and pass on their
Cytoplasm: Material outside the nucleus.
genes.
▪ Nature selects offspring, shaping • Site for metabolic activity.
species evolution. • Cytosol: Solution with dissolved
• Artificial selection: Humans select substances.
traits in an organism's offspring (e.g., • Organelles: Membrane-bound
pets, farm crops). subunits with specialized functions.
• Cytoskeleton: Supportive and
metabolic structure composed of
microtubules, microfilaments, and
Organismal evolution: intermediate filaments.
, Prokaryotic Cells: • Energy can be potential (stored) or
kinetic (active).
• Simple cellular organization with no
• Energy types: nuclear, magnetic,
nucleus or other membrane-bound
electrical, radiant, chemical, and
organelles.
thermal (heat).
• Contain ribosomes, pili, flagellum,
• Conversions between energy types
DNA, capsule, cell wall, and plasma
involve thermal energy.
membrane.
Laws of thermodynamics:
Eukaryotic Cells:
o First law (conservation of energy):
• Complex cellular organization with
The total energy in a closed system
membrane-bound organelles.
is constant.
Organelles: o Second law (increased entropy): The
free energy to do work decreases,
1. Nucleus: Contains DNA in the form
and disorder increases.
of chromosomes; controls cellular
• Earth is an open system, receiving
activities via genes.
radiant energy from the Sun.
2. Nucleolus: Site for ribosome
synthesis. • Photosynthetic organisms convert
3. Rough endoplasmic reticulum: Has radiant energy into organic
ribosomes, which are necessary for molecules.
protein synthesis. • Metabolism: Energy transfers within
4. Smooth endoplasmic reticulum: organisms based on metabolic
Involved primarily in lipid synthesis, pathways (catabolic/exergonic or
as it lacks ribosomes. anabolic/endergonic).
5. Golgi apparatus: Packaging center • Enzymes: Biological catalysts that
for molecules; synthesizes speed up reaction rates.
carbohydrates. • Adenosine triphosphate (ATP): A
6. Lysosome: Contains hydrolytic high-energy molecule. Energy is
enzymes for intracellular digestion. released by breaking phosphate
7. Peroxisome: Involved in hydrogen bonds.
peroxide synthesis and degradation.
Photosynthesis:
8. Chloroplast: Site of photosynthesis.
9. Chromoplast: Contains nongreen • Light-dependent reactions: Light
pigments. energy is transferred to electrons
10. Leukoplast: Stores starch. from H2O; O2 is a by-product.
11. Mitochondrion: Produces adenosine • Light-independent reactions:
triphosphate (ATP). Energized electrons are transferred to
12. Vacuole: General storage and space- CO2 to form glucose.
filling structure.
Cell Respiration:
Energy & Life