Cell Structure and Function: Study Notes for Anatomy & Physiology

Study Guide - Smart Notes

Tailored notes based on your materials, expanded with key definitions, examples, and context.

Cells are the basic structural and functional units of life. Understanding their components is essential for grasping how organisms function.

Three Main Parts: Plasma membrane, cytoplasm, and nucleus.
General Functions: Protection, communication, transport, metabolism, and reproduction.
Intracellular vs. Extracellular Fluid: Intracellular fluid is found inside cells; extracellular fluid surrounds cells and includes interstitial fluid and plasma.
Prokaryotic vs. Eukaryotic Cells: Prokaryotic cells lack a nucleus and membrane-bound organelles; eukaryotic cells have both.
Organelles: Specialized structures within cells that perform distinct functions (e.g., mitochondria, endoplasmic reticulum).

The plasma membrane is a selectively permeable barrier that regulates the movement of substances into and out of the cell.

Lipid Distribution: Lipids, primarily phospholipids, are arranged in a bilayer, providing fluidity and flexibility.
Carbohydrates and Proteins: Carbohydrates are attached to proteins and lipids on the extracellular surface, forming the glycocalyx. Proteins serve as channels, receptors, and enzymes.
Fluid Mosaic Model: Describes the dynamic arrangement of lipids and proteins in the membrane.

Cells exchange materials with their environment through various transport mechanisms.

Passive Transport: Includes diffusion, facilitated diffusion, and osmosis. No energy required.
Active Transport: Requires energy (ATP) to move substances against their concentration gradient.
Osmosis: Movement of water across a semipermeable membrane.
Hypertonic, Isotonic, Hypotonic: Terms describing relative solute concentrations and their effects on cells.
Vesicular Transport: Includes endocytosis (phagocytosis, pinocytosis) and exocytosis.

Organelles carry out specialized functions necessary for cell survival.

Endomembrane System: Includes the endoplasmic reticulum, Golgi apparatus, lysosomes, and vesicles.
Mitochondria: Site of ATP production.
Ribosomes: Site of protein synthesis.

The cytoskeleton provides structural support, facilitates movement, and organizes cellular components.

Three Components: Microfilaments (actin), intermediate filaments, and microtubules.
Centrioles, Cilia, Flagella: Centrioles organize microtubules; cilia and flagella enable movement.
Role in Cellular Motion: Cytoskeleton is essential for cell division, intracellular transport, and maintaining cell shape.

The nucleus is the control center of the cell, housing genetic material and coordinating activities such as growth and reproduction.

Chromatin and Chromosomes: Chromatin is the uncondensed form of DNA; chromosomes are condensed during cell division.
Nucleolus: Site of ribosome synthesis.
Interrelationships: Chromatin, chromosomes, and sister chromatids are all forms of genetic material at different stages of the cell cycle.

Protein synthesis is the process by which cells build proteins based on genetic instructions.

Gene Expression: DNA sequences are transcribed into RNA and translated into proteins.
Transcription: DNA is copied into messenger RNA (mRNA).
Translation: mRNA is decoded by ribosomes to assemble amino acids into proteins.
Roles of RNA: rRNA (ribosomal RNA), mRNA (messenger RNA), and tRNA (transfer RNA) are all essential for protein synthesis.

Key Equations:

The cell cycle is the series of events that cells go through as they grow and divide.

Key Equations:

Additional info: These notes are based on a syllabus outline and have been expanded with academic context for clarity and completeness.