7.2 notes

7.2 Cell Structure

Cell Organization

• It is easy to divide each cell into two major parts: the nucleus and the cytoplasm
• cytoplasm- portion of the cell outside of a nucleus
• ***NUCLEUS AND CYTOPLASM WORK TOGETHER IN A BUSINESS OF LIFE***
• Structures that act like specialized organs are organelles

THE NUCLEUS

• The nucleus contains all the cell's DNA and the coded instructions for making proteins and other important molecules
• Chromosomes carry the cell's genetic information and are found in the nucleus

Organelles That Store, Clean Up, and Support

• vacuoles- store materials like water, salts, protiens, and carbohydrates for a cell

• Lysosomes- small organelles filled with enzymes
• Lysosomes- break down lipids, carbs, and proteins into small molecules that can be used by the rest of the cell

The Cytoskeleton

• A network of protein filaments is a cytoskeleton
• The cytoskeleton helps a cell maintain its shape and is also involved in movement

Organelles That Build Protein

• Ribosomes- small particles of RNA and protein found throughout the cytoplasm in all the cells and are what proteins are assembled of
• Eukaryotic cells contain an international membrane system known as the endoplasmic reticulum
• Proteins are made on the rough ER include those that will be released from the cell as well as many membrane proteins destined for lysosomes and other specialized locations within a cell
• proteins produced in the rough ER move next into an organelle called a Golgi apparatus
• The Golgi apparatus modifies, sorts, and packages proteins and other materials from the endoplasmic reticulum for storage in the cell or release outside the cell

Organelles That Capture and Release Energy

• Chloroplasts are biological equivalents of solar power plants
• Chloroplasts capture the energy from sunlight and convert it into food that contains chemical energy in a process called photosynthesis

• Mitochondria are the power plants to the cell
• Mitochondria convert energy stored in food into compounds that are more convenient for the cell to use

Cellular Boundaries

• Cell Wall- strong supporting layer around the membrane of the cell, found in plant cells and most prokaryotes, provides much of the strength needed for plants to stand against the force of gravity
• Cell Membrane- found in every cell, regulates what enters and exits a the cell and also protects and supports the cell, contains a lipid bilayer which enables it to be flexible and strong
• Selectively Permeable Membrane- certain substances can not pass through the cell membrane, while others can

**This information can be found on pages 196-205 in your Biology hardcover**