Cell Biology and Genetics Overview

Cell Biology

Cell Theory: All living organisms are composed of cells; the cell is the basic unit of life; all cells arise from pre-existing cells.
Types of Cells:
- Prokaryotic: No nucleus, smaller, simpler (e.g., bacteria).
- Eukaryotic: Nucleus present, larger, complex (e.g., plant, animal cells).
Organelles:
- Nucleus: Stores genetic material (DNA).
- Mitochondria: Powerhouse of the cell, site of ATP production.
- Ribosomes: Protein synthesis.
- Endoplasmic Reticulum: Rough (with ribosomes) for protein synthesis, Smooth for lipid synthesis.
- Golgi Apparatus: Modifies, sorts, and packages proteins.
- Lysosomes: Digestive enzymes for waste processing.

Genetics

DNA Structure: Double helix made of nucleotides (adenine, thymine, cytosine, guanine).
Gene: A segment of DNA that codes for a protein.
Chromosomes: DNA packaged into structures, humans have 23 pairs.
Mendelian Inheritance: Traits are inherited according to specific ratios (dominant/recessive traits).
Genetic Variation: Caused by mutation, recombination, and independent assortment.

Evolution

Natural Selection: Process where organisms better adapted to their environment tend to survive and produce more offspring.
Speciation: Formation of new and distinct species in the course of evolution.
Evidence of Evolution:
- Fossil records.
- Comparative anatomy (homologous structures).
- Molecular biology (DNA similarities).

Ecology

Ecosystem: A community of living organisms interacting with their environment.
Biomes: Large ecological areas with distinct climates and ecosystems (e.g., desert, rainforest).
Food Chains/Webs: Represent the flow of energy from producers to consumers and decomposers.
Biogeochemical Cycles: Movement of elements and compounds through living organisms and the environment (e.g., carbon cycle, nitrogen cycle).

Physiology

Homeostasis: The ability to maintain a stable internal environment despite external changes.
Organ Systems:
- Circulatory System: Transports blood and nutrients.
- Respiratory System: Gas exchange (oxygen and carbon dioxide).
- Digestive System: Breaks down food and absorbs nutrients.
- Nervous System: Coordinates body activities and processes sensory information.

Plant Biology

Photosynthesis: Process by which plants convert light energy into chemical energy (glucose) using chlorophyll.
Plant Structure:
- Roots: Absorb water and nutrients.
- Stems: Support and transport.
- Leaves: Site of photosynthesis.
Reproduction: Can be sexual (seeds, flowers) or asexual (cuttings, runners).

Microbiology

Bacteria: Prokaryotic microorganisms, can be beneficial (gut bacteria) or pathogenic (causing disease).
Viruses: Non-living entities that require a host to reproduce; can infect all types of life forms.
Fungi: Eukaryotic organisms, decomposers, can be unicellular (yeast) or multicellular (mushrooms).

Biochemistry

Macromolecules:
- Carbohydrates: Energy storage (sugars, starches).
- Proteins: Made of amino acids, perform various functions (enzymes, structural).
- Lipids: Fats and oils, important for cell membranes and energy storage.
- Nucleic Acids: DNA and RNA, carry genetic information.

Biotechnology

Genetic Engineering: Manipulating an organism's DNA to enhance desired traits (e.g., GMOs).
CRISPR: A tool for editing genes with precision.
Biopharmaceuticals: Drugs produced using biotechnology (e.g., insulin production using recombinant DNA).

Cell Biology

Cell Theory: Fundamental concept stating all living organisms consist of cells, which are the basic units of life, and all cells originate from pre-existing ones.
Types of Cells: Prokaryotic cells lack a nucleus and are generally smaller and simpler (e.g., bacteria); eukaryotic cells contain a nucleus, are larger, and more complex (e.g., plant and animal cells).
Organelles:
- Nucleus: Holds and protects genetic material (DNA).
- Mitochondria: Known as the powerhouses of the cell, they produce ATP, the energy currency of cells.
- Ribosomes: Sites for protein synthesis where amino acids are assembled into proteins.
- Endoplasmic Reticulum (ER): Rough ER has ribosomes for protein synthesis; Smooth ER is involved in lipid synthesis.
- Golgi Apparatus: Modifies, sorts, and packages proteins for secretion or use within the cell.
- Lysosomes: Contain digestive enzymes that break down waste materials and cellular debris.

Genetics

DNA Structure: Comprises a double helix formed by nucleotides containing adenine, thymine, cytosine, and guanine.
Gene: Functional unit of heredity, a segment of DNA coding for a specific protein.
Chromosomes: Structures of DNA packaging; humans possess 23 pairs, totaling 46 chromosomes.
Mendelian Inheritance: Describes how genes for traits are passed from parents to offspring with predictable ratios of dominant and recessive traits.
Genetic Variation: Arises from processes like mutations, recombination during sexual reproduction, and independent assortment of chromosomes.

Evolution

Natural Selection: Mechanism by which organisms that are better suited to their environment tend to survive and reproduce more successfully.
Speciation: The evolutionary process leading to the emergence of new species.
Evidence of Evolution:
- Fossil records provide physical evidence of historical life forms.
- Comparative anatomy discovers homologous structures indicating shared ancestry.
- Molecular biology explores genetic similarities across species through DNA analysis.

Ecology

Ecosystem: A complex network of living organisms interacting with each other and their physical environment.
Biomes: Major ecological zones with specific climate patterns and ecosystems, such as deserts and rainforests.
Food Chains/Webs: Depict the energy flow from producers (like plants) to various levels of consumers and decomposers.
Biogeochemical Cycles: Cycles that illustrate the movement of essential elements (e.g., carbon and nitrogen) through biological and geological processes.

Physiology

Homeostasis: The regulatory process that maintains a stable internal environment in organisms despite external changes.
Organ Systems:
- Circulatory System: Circulates blood and nutrients throughout the body.
- Respiratory System: Facilitates gas exchange by inhaling oxygen and exhaling carbon dioxide.
- Digestive System: Breaks down food into nutrients that the body can absorb.
- Nervous System: Controls body functions and processes sensory information.

Plant Biology

Photosynthesis: The process in which plants convert solar energy into chemical energy, specifically glucose, using chlorophyll.
Plant Structure:
- Roots: Absorb water and nutrients from the soil.
- Stems: Provide support and transport nutrients and water.
- Leaves: Main site for photosynthesis.
Reproduction: Plants can reproduce sexually through seeds and flowers or asexually through methods like cuttings and runners.

Microbiology

Bacteria: Simple prokaryotic organisms, which can play beneficial roles (e.g., gut flora) or act as pathogens (disease-causing).
Viruses: Non-living entities that depend on host cells for reproduction and can infect various life forms.
Fungi: Eukaryotic decomposers that can exist as single cells (yeast) or multicellular structures (mushrooms).

Biochemistry

Macromolecules:
- Carbohydrates serve as energy storage (e.g., sugars, starches).
- Proteins, composed of amino acids, perform myriad functions including catalysis (enzymes) and structural integrity.
- Lipids are fats and oils vital for cell membranes and energy storage.
- Nucleic Acids (DNA and RNA) store and transmit genetic information.

Biotechnology

Genetic Engineering: The process of altering an organism's DNA to improve desired traits, such as creating genetically modified organisms (GMOs).
CRISPR: Advanced technology for precise gene editing, revolutionizing genetic research.
Biopharmaceuticals: Medications produced through biotechnological approaches, exemplified by insulin made via recombinant DNA technology.