Cell Biology
The branch of biology that studies the structure, function, and behavior of cells, including organelles and molecular processes.
cells
the basic structural and functional units of life
Robert Hooke
who observed cork cells under a simple microscope and coined the term "cell."
Matthias Schleiden and Theodor Schwann
In the 19th century, __________ and __________ proposed the cell theory, which states that all living organisms are composed of cells, cells are the basic units of structure and function in organisms, and cells arise only from pre-existing cells.
Cell Membrane
Surrounds the cell, regulates substance passage, and is composed of a phospholipid bilayer with embedded proteins.
Cytoplasm
Gel-like substance filling the cell, where organelles are suspended. Contains various ions, enzymes, and other molecules necessary for cellular processes.
Nucleus
Houses the genetic material (DNA) of the cell and controls cellular activities. Surrounded by a nuclear envelope and contains the nucleolus, where ribosomal RNA is synthesized.
Mitosis and Meiosis
Processes of cell division crucial for growth, repair, and reproduction.
Organelles
Specialized structures within cells like mitochondria, endoplasmic reticulum, Golgi apparatus, and lysosomes performing specific functions.
Metabolism
Sum of chemical reactions in a cell.
Cell Division
Process by which cells replicate and divide to produce new cells. (mitosis and meiosis)
Cellular Communication
Cells communicate with each other through signaling molecules, allowing coordination of physiological processes and responses to external stimuli.
Differentiation
Process by which cells become specialized in structure and function to perform specific roles within an organism.
Microscopy
Techniques using microscopes to visualize cells and structures.
Cell Culture
Cells can be cultured in vitro under controlled conditions to study their behavior, growth, and responses to experimental manipulations.
Molecular Biology Techniques
__________________ such as polymerase chain reaction (PCR), gel electrophoresis, and DNA sequencing, are used to study cellular processes at the molecular level.
Medicine, Biotechnology, Regenerative Medicine, Environmental Science
Applications of Cell Biology
Ecosystem
Community of living organisms interacting with the environment.
Biotic Components of Ecosystems
Include all living organisms within an ecosystem, from microorganisms to plants and animals. These organisms interact with each other and with their environment, shaping the dynamics of the ecosystem.
Abiotic Components of Ecosystems
Consist of non-living factors that influence the structure and function of ecosystems. These include physical factors such as temperature, sunlight, soil composition, water availability, and topography.
Biodiversity
Variety of species within an ecosystem, indicating ecosystem health and resilience.
Ecological Interactions
Organisms within an ecosystem interact with each other in various ways, forming complex networks of relationships.
Predation
One organism (predator) consumes another organism (prey) for food.
Competition
Organisms compete for limited resources such as food, water, and habitat.
Mutualism
Both organisms benefit from the interaction (e.g., pollination by bees).
Parasitism
One organism (parasite) benefits at the expense of another organism (host).
Commensalism
One organism benefits while the other is unaffected (e.g., epiphytic plants growing on trees).
Ecological Succession
refers to the process by which an ecosystem undergoes predictable changes in species composition in an ecosystem over time.
Primary succession
occurs in newly formed habitats, such as bare rock or volcanic lava, where pioneer species colonize the area and gradually pave the way for more complex communities.
Secondary succession
occurs in habitats that have been disturbed or altered but still retain soil and some vegetation. It typically involves the reestablishment of vegetation following events like fires or clear-cutting.
Ecology
the scientific study of interactions between organisms and their environment. It encompasses the relationships between organisms, as well as their interactions with abiotic factors such as temperature, water, sunlight, and soil.
Innate Immunity
Non-specific defense mechanisms providing immediate protection against pathogens.
Individual, Population, Community, Ecosystem, Biome, Biosphere
Levels of Ecological Organization
Individual
The smallest level of organization, consisting of a single organism.
Population
A group of individuals of the same species living in the same area and interbreeding.
Community
All the populations of different species living and interacting in a particular area.
Ecosystem
A community of organisms and their physical environment, including biotic and abiotic components.
Biome
A large geographic area characterized by distinct climate, vegetation, and animal life.
Biosphere
The global sum of all ecosystems, encompassing the regions of the Earth inhabited by living organisms.
Habitat
The specific environment in which an organism lives and to which it is adapted.
Niche
The role or function of an organism within its ecosystem, including its interactions with other organisms and its use of resources.
Energy Flow
The transfer of energy through trophic levels in an ecosystem, from producers (plants) to consumers (herbivores, carnivores) to decomposers (bacteria, fungi).
Food Chains and Food Webs
Diagrams representing the transfer of energy and nutrients through feeding relationships in an ecosystem.
Nutrient Cycling
The movement and recycling of essential nutrients (such as carbon, nitrogen, and phosphorus) through biotic and abiotic components of ecosystems.
Biomes
are large-scale ecological regions characterized by distinct climate, vegetation, and animal life. Examples include tropical rainforests, temperate forests, grasslands, deserts, tundras, and aquatic ecosystems.
Structural adaptations
type of adaptation that involve physical features or body structures that enhance an organism's ability to survive (camouflage coloration, protective shells).
Behavioral adaptations
type of adaptation that are actions or behaviors that organisms perform to increase their chances of survival (migration, hibernation).
Physiological adaptations
type of adaptation that are internal mechanisms or processes that help organisms cope with environmental challenges (temperature regulation, water conservation).
immune system
defends the body against pathogens through mechanisms such as phagocytosis, antibody production, and cell-mediated immunity.
Bacteria, Viruses, Fungi, Protists
Types of Pathogens
Bacteria
Single-celled prokaryotic organisms that can be beneficial or harmful. Pathogenic bacteria cause diseases such as tuberculosis, pneumonia, and food poisoning.
Viruses
Small infectious agents that require a host cell to replicate. Common viral diseases include influenza, HIV/AIDS, and COVID-19.
Fungi
Eukaryotic organisms that include yeasts, molds, and mushrooms. Fungal infections can affect the skin, nails, respiratory tract, and internal organs
Protists
Single-celled eukaryotic organisms that include protozoa and algae. Some protists, such as Plasmodium spp. (causative agents of malaria), can cause serious diseases
Innate Immunity
Non-specific defense mechanisms that provide immediate, generalized protection against pathogens. Examples include physical barriers (skin, mucous membranes), phagocytic cells (macrophages, neutrophils), and antimicrobial proteins (complement system).
Adaptive Immunity
Specific immune responses that develop after exposure to specific pathogens or antigens. Provides long-term immunity and immunological memory
Vaccination
is a preventive measure that stimulates the immune system to produce an immune response against a particular pathogen or antigen
contain weakened or inactivated forms of pathogens, antigens derived from pathogens, or genetic material (e.g., mRNA) encoding antigenic proteins.
Antibiotics
are drugs used to treat bacterial infections by inhibiting bacterial growth or killing bacteria
Energy
is vital for life processes, and organisms obtain and utilize energy through processes like photosynthesis and cellular respiration.
Bioenergetics
is the study of energy flow within living systems, focusing on how organisms acquire, transform, and utilize energy to sustain life processes.
Adenosine triphosphate (ATP)
is the primary energy currency of cells, storing and transferring energy for cellular activities.
consisting of adenine, ribose, and three phosphate groups, serving as the primary energy carrier in cells.
Cellular Respiration
The process of breaking down organic molecules to produce ATP, involving glycolysis, the citric acid cycle, and the electron transport chain.
Glycolysis, Citric Acid Cycl (Krebs Cycle), Electron Transport Chain (ETC)
Three main stages of cellular respiration:
Glycolysis
Occurs in the cytoplasm and involves the breakdown of glucose into pyruvate, producing a small amount of ATP and NADH.
Citric Acid Cycle (Krebs Cycle)
Takes place in the mitochondrial matrix and completes the oxidation of glucose-derived pyruvate to produce more ATP, NADH, and FADH2.
Electron Transport Chain (ETC)
Located in the inner mitochondrial membrane, the ETC uses electron carriers (NADH and FADH2) to generate a proton gradient, driving ATP synthesis through oxidative phosphorylation.
Photosynthesis
The conversion of light energy into chemical energy (glucose) by autotrophic organisms through light-dependent reactions and the Calvin Cycle.
Light-dependent Reactions, Calvin Cycle (Light-Independent Reactions)
Two main stages of photosynthesis:
Light-dependent Reactions
stage of photosynthesis that occur in the thylakoid membranes of chloroplasts, where light energy is captured by chlorophyll and used to generate ATP and NADPH.
Calvin Cycle (Light-Independent Reactions):
stage of photosynthesis that takes place in the stroma of chloroplasts and involves the fixation of carbon dioxide and the synthesis of glucose using ATP and NADPH generated during the light-dependent reactions.
Disorders Related to Bioenergetics
Health conditions like diabetes mellitus, mitochondrial diseases, and obesity resulting from disruptions in bioenergetic processes.
Diabetes Mellitus
Characterized by impaired glucose metabolism, resulting in high blood glucose levels (hyperglycemia).
Mitochondrial Diseases
Caused by mutations in mitochondrial DNA or nuclear genes encoding mitochondrial proteins, leading to defects in oxidative phosphorylation and ATP production.
Obesity
Resulting from an imbalance between energy intake and expenditure, leading to excessive accumulation of body fat and associated health risks.
Homeostasis
The maintenance of internal stability in response to external changes through regulation of factors like temperature, pH, and water balance.
Genetics
explores how traits are passed from parents to offspring through genes located on chromosomes.
Variation
arises from genetic differences and environmental influences, leading to diversity within populations.
Evolution
as described by Charles Darwin's theory of natural selection, explains how populations change over time in response to environmental pressures.
Human Physiology
Study of organ systems like digestive, respiratory, circulatory, and nervous systems, crucial for maintaining homeostasis and overall health.
Biotechnology and Genetic Engineering
Involves manipulating living organisms for various purposes, including genetic engineering for agricultural, medical, and industrial applications, with ethical considerations.