Cell Biology and Genetics Overview

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, unicellular (e.g., bacteria).
- Eukaryotic: Nucleus present, larger, can be unicellular or multicellular (e.g., plant and animal cells).
Cell Organelles:
- Nucleus: Contains genetic material (DNA).
- Mitochondria: Powerhouse of the cell, produces energy (ATP).
- Ribosomes: Site of protein synthesis.
- Endoplasmic Reticulum (ER):
  - Rough ER: Studded with ribosomes, synthesizes proteins.
  - Smooth ER: Synthesizes lipids and detoxifies.
- Golgi Apparatus: Modifies, sorts, and packages proteins and lipids.

DNA Structure: Double helix made of nucleotides (A, T, C, G).
Gene: A segment of DNA that codes for a protein.
Chromosomes: Structures that contain DNA, humans have 46 (23 pairs).
Mendelian Genetics:
- Law of Segregation: Alleles separate during gamete formation.
- Law of Independent Assortment: Genes for different traits can segregate independently.

Natural Selection: Process by which individuals with favorable traits are more likely to survive and reproduce.
Adaptation: Trait that enhances survival and reproduction in a specific environment.
Speciation: Formation of new species through evolutionary processes.

Ecosystems: Community of living organisms interacting with their environment.
Biomes: Large geographic biotic units defined by climate and vegetation (e.g., tundra, rainforest).
Food Webs: Interconnected food chains showing energy flow through ecosystems.

Body Systems:
- Circulatory: Transports blood, nutrients, gases.
- Respiratory: Facilitates gas exchange (oxygen and carbon dioxide).
- Digestive: Breaks down food for nutrient absorption.
- Nervous: Controls body functions through signaling.
- Endocrine: Regulates bodily functions through hormones.

Bacteria: Prokaryotic microorganisms, can be beneficial or pathogenic.
Viruses: Non-cellular entities that require a host cell to replicate.
Fungi: Eukaryotic organisms, can be unicellular (yeasts) or multicellular (molds).

Photosynthesis: Process by which plants convert sunlight into chemical energy (glucose).
Plant Cells vs. Animal Cells:
- Plant cells have cell walls and chloroplasts; animal cells do not.

Genetic Engineering: Manipulation of an organism's DNA to achieve desired traits.
CRISPR: A technology for editing genomes with precision.

Proteins: Made of amino acids, perform various functions in the body (structural, enzymatic).
RNA Types:
- mRNA: Messenger RNA, carries genetic information from DNA to ribosomes.
- tRNA: Transfer RNA, brings amino acids to ribosomes during protein synthesis.

Macromolecules:
- Carbohydrates: Provide energy (e.g., glucose).
- Proteins: Structural and functional roles (enzymes, hormones).
- Lipids: Energy storage, membrane structure (fats, oils).
- Nucleic Acids: DNA and RNA, store and transmit genetic information.

Cell Theory states that all living organisms consist of cells, which are the basic units of life that arise from pre-existing cells.
Types of Cells:
- Prokaryotic cells lack a nucleus, are generally smaller, and primarily unicellular (e.g., bacteria).
- Eukaryotic cells possess a nucleus, are larger, and can exist as unicellular or multicellular organisms (e.g., plants and animals).
Cell Organelles:
- Nucleus houses genetic material (DNA).
- Mitochondria are known as the powerhouse of the cell, where ATP (energy) is produced.
- Ribosomes are the sites of protein synthesis.
- Endoplasmic Reticulum (ER):
  - Rough ER is studded with ribosomes and is involved in protein synthesis.
  - Smooth ER synthesizes lipids and aids in detoxification.
- Golgi Apparatus modifies, sorts, and packages proteins and lipids.

DNA Structure consists of a double helix format made of nucleotides: adenine (A), thymine (T), cytosine (C), and guanine (G).
Gene: A DNA segment that encodes a specific protein.
Chromosomes: Structures that contain DNA; humans have 46 chromosomes (23 pairs).
Mendelian Genetics principles reveal that:
- The Law of Segregation states alleles separate during gamete formation.
- The Law of Independent Assortment indicates that genes for different traits segregate independently.

Natural Selection is the process where individuals with advantageous traits are more likely to survive and reproduce.
Adaptation refers to a trait that improves an organism's chances of survival and reproduction in a certain environment.
Speciation is the evolutionary process that leads to the formation of new species.

Ecosystems are communities of living organisms interacting with their physical environment.
Biomes are large geographic biotic units characterized by distinct climate and vegetation types, such as tundras and rainforests.
Food Webs illustrate interconnected food chains, highlighting the flow of energy through ecosystems.

Body Systems include:
- Circulatory System: Transports blood, nutrients, and gases throughout the body.
- Respiratory System: Facilitates the exchange of gases (oxygen intake and carbon dioxide expulsion).
- Digestive System: Breaks down food for nutrient absorption.
- Nervous System: Controls body functions through signaling networks.
- Endocrine System regulates physiological processes via hormone secretion.

Bacteria are prokaryotic microorganisms that can be either beneficial or pathogenic.
Viruses are non-cellular entities that replicate only within a host cell.
Fungi consist of eukaryotic organisms that can be unicellular (e.g., yeasts) or multicellular (e.g., molds).

Photosynthesis is the process by which plants convert sunlight into chemical energy, producing glucose.
Plant Cells vs. Animal Cells: Plant cells have cell walls and chloroplasts, whereas animal cells lack these structures.

Genetic Engineering involves manipulating an organism’s DNA to cultivate desired characteristics.
CRISPR is a precise genome-editing technology that facilitates alterations in DNA sequences.

Proteins are made from amino acids and serve various functions, including structural support and enzymatic activities.
RNA Types:
- mRNA (messenger RNA) carries genetic information from DNA to ribosomes for protein synthesis.
- tRNA (transfer RNA) transports amino acids to ribosomes for protein assembly.

Macromolecules consist of:
- Carbohydrates: Serve as a primary energy source (e.g., glucose).
- Proteins: Play structural and functional roles, including enzymatic and hormonal functions.
- Lipids: Function in energy storage and cell membrane structure (e.g., fats, oils).
- Nucleic Acids: DNA and RNA serve as carriers of genetic information, responsible for storage and transfer.