Animal Cell Structure and Organelles

• Animal cells consist of components like the extracellular matrix and various organelles.

Inside the Cell (Cytoplasm & Organelles)

• Cytoplasm is the jelly-like fluid filling the cell, suspending the organelles.
• Organelles are tiny structures within cells performing specific functions.

Energy & Protein Factories

• Mitochondria are the cell's "powerhouse," producing energy (ATP) from food.
• Ribosomes are tiny factories that construct proteins, floating in the cytoplasm or attaching to the endoplasmic reticulum.

Processing & Transporting

• The Endoplasmic Reticulum (ER) is a network of tubes transporting proteins (rough ER) and lipids (smooth ER).
• The Golgi Apparatus is the cell's "post office," modifying, packaging, and dispatching proteins and lipids to their destination.

Cleaning & Recycling

• Lysosomes function as "garbage disposal," breaking down waste, bacteria, and old cell components.
• Peroxisomes detoxify harmful substances and break down fats.
• Vacuoles store water, nutrients, and waste, being large in plant cells for shape maintenance.

Cell Division & Structure

• Centrioles are small structures aiding cell division, found in animal cells.
• Centrosomes organize microtubules for cell division and structure.

Control Center

• The Nucleus is the cell's "brain," housing DNA and regulating all cell activities.

Movement & Communication

• Flagella & Cilia are hair-like structures that move cells (flagella) or substances around the cell (cilia).

Cell Protection & Support

• The Plasma Membrane is the cell's outer layer, controlling inflow and outflow.
• The Cytoskeleton is a network of fibers providing cell shape, strength, and internal movement.
• The Extracellular Matrix is a network outside the cell, providing support and facilitating cell communication

Key Cellular Processes

Energy & Chemical Reactions in the Body

• Metabolism is the total of all chemical reactions essential for life, including the breakdown of substances and the building of new ones.
• Catabolism breaks down large molecules into smaller ones to release energy.
• Anabolism builds larger molecules from smaller ones, using energy such as in muscle growth.

Movement & Use of Energy

• Transport involves moving substances like nutrients, oxygen, and waste within cells or throughout the body.
• Adenosine Triphosphate (ATP) is the main energy molecule that fuels cell activities.
• Adenosine Diphosphate (ADP) is a lower-energy molecule formed when ATP loses a phosphate group.
• Inorganic Phosphate (Pi) is a free phosphate molecule that can be added to ADP to regenerate ATP.
• Phosphorylation is the process of adding a phosphate group (Pi) to a molecule, often ADP, to make ATP and store energy.

How Substances Enter & Leave a Cell

Passive Transport (No Energy Needed)

• Osmosis is the movement of water across a membrane from low to high solute concentration areas.
• Diffusion is the movement of molecules from high to low concentration until evenly spread out.
• Bulk Flow is the movement of large amounts of fluid and solutes due to pressure differences.
• Facilitated Diffusion involves the movement of molecules across a membrane with the help of a protein, without using energy.

Active Transport (Energy Needed - Uses ATP)

• Active Transport moves molecules against their concentration gradient, requiring energy.
• Vesicular Transport moves large molecules or particles using vesicles, including:
  • Endocytosis, which brings substances into the cell.
  • Exocytosis, which sends substances out of the cell.

Main Types of Cells in Biology

• Prokaryotic Cells are simple cells without a nucleus, like bacteria, with DNA floating in the cytoplasm.
• Eukaryotic Cells are more complex cells with a nucleus and organelles, found in plants, animals, and humans.

Genetic Material

• DNA (Deoxyribonucleic Acid) carries genetic instructions for growth, development, and function.
• A Plasmid is a small, circular DNA piece in prokaryotic cells, carrying extra genes.

Movement & Protection

• Flagellum is a long, whip-like tail that helps cells move.
• A Capsule is a protective outer layer in some bacteria, aiding surface adhesion and immune evasion.

Inside the Cell

• Cytoplasm is the jelly-like fluid in the cell where organelles float.
• Nucleus is the control center of eukaryotic cells, storing DNA and managing activities.
• Centriole: A small structure in animal cells that helps with cell division.

Protein & Energy Production

• Ribosomes make proteins, found in both prokaryotic and eukaryotic cells.
• Rough Endoplasmic Reticulum (Rough ER) has ribosomes on its surface, aiding in protein production and transport.
• Smooth Endoplasmic Reticulum (Smooth ER) makes lipids and detoxifies harmful substances.
• Mitochondria are the cell's "powerhouse," producing energy (ATP) from food.

Packaging & Transport

• Golgi Apparatus acts as the cell's "post office," modifying, sorting, and sending proteins and lipids as needed.

Function of the 4 Main Tissue Types of the Human Body

Epithelial Tissue (Covers & Protects)

• Absorption occurs in some epithelial tissues, absorbing nutrients, water, and other substances.
• Epithelial cells act as a Barrier to Absorption, preventing harmful substances from entering the body.
• Covering & Lining tissue forms the outer layer of skin and lines organs, blood vessels, and cavities.

Connective Tissue (Supports & Connects)

• Bind Structures with connective tissues holding various parts of the body together.
• Protection is provided by cushioning and shielding organs.
• Immunological Function is carried out by some connective tissues, like blood and lymph, which help fight infections.
• Fat-Storage in the form of adipose tissue stores energy and insulates the body.
• Transport of oxygen, nutrients, and waste throughout the body via blood.
• Tissue Damage Repair involves connective tissue aiding injury repair.
• Structural Support is provided in the form of shape and strength to the body.

Muscle Tissue (Moves & Produces Heat)

• Movement is enabled by muscle tissue in the body and internal organs.
• Posture Maintenance is supported by maintaining correct posture even when the body is at rest.
• Thermogenesis is when Muscles generate heat to maintain body temperature, especially during shivering.

Nervous Tissue (Communication & Control)

• Nervous tissue consists of nerve cells (neurons) and supporting cells, coordinating body functions by transmitting signals.
• Action Potentials are electrical signals used by neurons to communicate messages quickly.
• Control of body functions is achieved by sending and receiving signals.
• Sensory information, like touch, temperature, and pain, is detected by the nervous tissue and sent to the brain.
• Integration of sensory information happens in the brain and spinal cord to make decisions and coordinate responses.
• Motor Functions involve nervous signals directing muscles to contract and glands to release hormones.