Cell Structure and Function

Cells are the basic units of life, exhibiting a wide range of shapes and sizes adapted to their specific functions.
All cells share fundamental features, including a plasma membrane, cytoplasm, and DNA.
Prokaryotic cells, like bacteria, lack a nucleus and other membrane-bound organelles.
Eukaryotic cells, including plant and animal cells, possess a nucleus and various organelles, each with a specific role.
The cytoplasm is a gel-like substance filling the cell, containing organelles and enzymes for metabolic processes.
The plasma membrane controls what enters and exits the cell, maintaining homeostasis.
The nucleus houses the cell's DNA, directing cellular activities and regulating gene expression.
Mitochondria are the "powerhouses" of the cell, generating energy through cellular respiration.
Chloroplasts are found in plant cells, harnessing light energy to produce sugars (photosynthesis).
Ribosomes synthesize proteins, vital for cell structure and function.
Endoplasmic reticulum (ER) is a network of membranes involved in protein and lipid synthesis.
Golgi apparatus modifies, sorts, and packages proteins and lipids for transport.
Vacuoles store water, nutrients, and waste products, maintaining turgor pressure in plant cells.
Lysosomes contain enzymes for digestion and recycling cellular components.
Cytoskeleton provides structural support and facilitates cell movement.

Four major classes of biological macromolecules are crucial to life: carbohydrates, lipids, proteins, and nucleic acids.
Carbohydrates, composed of carbon, hydrogen, and oxygen, serve as a primary energy source.
Simple sugars (monosaccharides) like glucose are the basic units, while larger structures (polysaccharides) like starch and glycogen store energy.
Lipids, primarily composed of carbon and hydrogen, are hydrophobic and diverse in function.
Fats (triglycerides) store energy, phospholipids form cell membranes, and steroids have diverse roles in hormone production.
Proteins, polymers of amino acids, perform a vast array of functions including structural support, transport, and catalysis (enzymes).
Nucleic acids, DNA and RNA, store and transmit genetic information.
DNA carries the genetic code, determining the traits of an organism.
RNA plays a crucial role in protein synthesis and other cellular processes.

Cellular respiration is a metabolic process where cells break down glucose to release ATP, the primary energy currency of the cell.
Photosynthesis converts light energy into chemical energy in the form of glucose, a vital process for autotrophs.
Cellular transport includes passive (diffusion, osmosis) and active (protein pumps) mechanisms.
Mitosis is the process of cell division for growth and repair in somatic cells.
Meiosis is the process of cell division for gamete formation (sperm and egg).
DNA replication ensures that genetic material is copied accurately before cell division.
Transcription and translation are the processes through which genetic information is converted into proteins.

Ecology is the study of the interactions between organisms and their environment.
Biotic factors are living components, while abiotic factors are non-living components of the environment.
Different levels of organization in ecology include individuals, populations, communities, and ecosystems.
Ecosystems consist of interacting organisms and their physical environment.
Food chains and food webs describe the flow of energy through ecosystems.
Symbiotic relationships (mutualism, commensalism, parasitism) illustrate various interactions between species.
Population dynamics involve factors such as birth rate, death rate, and migration.
Ecological succession describes the gradual change in an ecosystem over time.
Biodiversity is the variety of life in an area.
Human activities significantly impact ecosystems and biodiversity.

Genetics is the study of heredity and variation of traits.
Genes are segments of DNA that code for specific proteins.
Chromosomes are organized structures containing DNA and proteins.
Inheritance patterns describe how traits are passed from parents to offspring.
Mendelian genetics describes the principles of inheritance established by Gregor Mendel.
Non-Mendelian inheritance patterns exist beyond simple dominant/recessive relationships.
Mutations are alterations in DNA sequences that can lead to variations in traits.
Genetic technologies, like PCR and CRISPR, allow researchers to manipulate and analyze DNA.
Gene expression regulates when and how genes are used.

Evolution is the process of change in the heritable characteristics of biological populations over successive generations.
Natural selection is a key mechanism driving evolution, favoring traits that enhance survival and reproduction.
Genetic variation is essential for evolution to occur.
Adaptation is the process by which organisms become better suited to their environment.
Common ancestry is a concept central to understanding the relationships between species.
Speciation is the formation of new and distinct species in the course of evolution.
Fossil evidence, comparative anatomy, and molecular biology provide support for evolutionary theory.