Cell Biology Basics

Study Notes

Cells and Organelles

Cells are the basic living units of all organisms, highly organized and specialized.
Organelles are specialized structures within cells that perform specific functions.
Cytoplasm is a jelly-like substance that holds organelles and is enclosed by the cell membrane.

Cell Membrane/Plasma Membrane

The cell membrane is the outermost component of the cell, forming a selective barrier between intracellular and extracellular substances.
It is composed of phospholipids, proteins, cholesterol, and carbohydrates.
Phospholipids form a double layer with polar (hydrophilic) and nonpolar (hydrophobic) regions.
Proteins float among phospholipid molecules, functioning as membrane channels, carrier molecules, receptor molecules, enzymes, or structural supports.
Cholesterol provides added strength and stability by limiting phospholipid movement.
Carbohydrates may be bound to some molecules, modifying their functions.

Organelles and Their Functions

Nucleus contains genetic material (DNA) and nucleoli, and is the site of RNA synthesis and ribosomal subunit assembly.
Ribosomes are the site of protein synthesis.
Rough Endoplasmic Reticulum has many ribosomes attached and is the site of protein synthesis.
Smooth Endoplasmic Reticulum is the site of lipid synthesis and participates in detoxification.
Golgi Apparatus modifies CHON structure and packages CHON in secretory vesicles.
Secretory Vesicle contains materials produced in the cell and is formed by the Golgi Apparatus.
Lysosome contains enzymes that digest material taken into the cell.
Peroxisome breaks down fatty acids, amino acids, and hydrogen peroxide.
Mitochondria is the site of aerobic respiration and the major site of ATP synthesis.
Microtubule supports cytoplasm, assists in cell division, and forms components of cilia and flagella.
Centrioles facilitate the movement of chromosomes during cell division.
Cilia are located on the cell surface and move substances over certain cells.
Flagella are found on proper sperm cells.
Microvilli increase the surface area of certain cells.

Cell Transport

Movement through the cell membrane can be passive or active.
Passive Membrane Transport does not require energy and includes diffusion, osmosis, and facilitated diffusion.
Active Membrane Transport requires energy, usually in the form of ATP, and includes active transport, secondary active transport, endocytosis, and exocytosis.
Diffusion is the movement of a solute from an area of higher concentration to an area of lower concentration within a solvent.
Osmosis is the diffusion of water across a selectively permeable membrane.
Osmotic pressure is the force required to prevent movement of water across a selectively permeable membrane.

Description

This quiz covers the basic components and functions of cells, including organelles, cytoplasm, and the cell membrane. Test your knowledge of cell metabolism, molecule synthesis, communication, and reproduction.