Cell Structures 7-2

Cell Structures The cell has many parts that work together like a machine in order to carry out all of it’s life processes They all have unique and specialized functions that the cell could not do without

Cell Wall In some cells, mainly plants and bacteria a cell wall may be found The cell wall is responsible for providing rigid support and protection for the cell It is located outside of the cell membrane

Nucleus The nucleus controls most cell processes and contains the hereditary information of DNA The nucleus has many parts that work together to make up the full nucleus

The outer most part of the nucleus is called the nuclear envelope The nuclear envelope is responsible for movement of RNA in and out of the cell

The nucleolus is a small dense region inside the nucleus It has recently been discovered that the nucleolus is the plays a role in ribosome construction

Inside the nucleus is the genetic material of a cell This genetic material is called chromatin During cell replication it will coil tightly and condense creating chromosomes

Cytoskeleton Many cells have a special structure called the cytoskeleton The cytoskeleton is the frame work of a cell that is made of protein filaments and helps maintain shape and cell movement

The cytoskeleton has two main parts The microtubules and microfilaments

The microtubules are hollow tubes of protein that help maintain shape and serve as a set of “tracks” for organelle movement Microfilaments are long thin fibers that function in the movement and support of the cell

Organelles in the cytoplasm The cytoplasm is the home for many of the cells organelles This includes the ribosomes, ER, golgi apparatus, lysosomes, vacuoles, chloroplasts, and mitochondria

Ribosomes Ribosomes are very small organelles which are located in the cytoplasm and on parts of the ER They are the makers of proteins and get their instructions in the form of a coded message from the nucleus

Endoplasmic Reticulum (ER) The ER is the organelle in which the components for the cell membrane are assembled and some proteins are altered There are two kinds of ER Rough ER and Smooth ER Rough ER has ribosomes and SMooth ER Does not

Rough ER and Smooth ER Rough ER has ribosomes and Smooth ER does not

Golgi Apparatus Proteins that are made by the Rough ER are moved into a stack of membranes called the golgi apparatus Enzymes in the golgi apparatus attach carbohydrates and lipids to proteins

Lysosomes Lysosomes are small organelles that are filled with enzymes These enzymes break down lipids, carbohydrates, and proteins from food into particles that can be used in other parts of the cell

Vacuoles Cells often store materials such as water, salts, proteins and carbohydrates for later use They are stored in sacs called vacuoles In plants the vacuoles are much larger than animal cells

Chloroplasts Chloroplasts are mainly found in plants They are not in animal cells or fungi Their job is to use the energy from sunlight to make energy rich food molecules known as chlorophyll

Mitochondria Mitochondria are organelles that release energy from stored food molecules They are often called the “power house” of the cell because they provide energy for other cell processes