Cells Part 1

Cell theory

"The theory that all living things are made of cells, that cells are the basic units of organisms, and that cells come only from existing cells"

Cytoplasm

A term for all the contents of a cell other than the nucleus. Even though the cartoon drawings do not look like it, the cytoplasm contains mostly water.

Both Eukaryote and Prokaryote

Have ribosomes to make proteins cytoplasm cell membrane Both have DNA

Cell Wall

In addition to cell membranes, plants have cell walls. Cell walls provide protection and support for plants. In land plants, the cell wall is mostly made of cellulose.

Endoplasmic reticulum (ER)

It is a network of membranes throughout the cytoplasm of the cell. There are two types of ER. When ribosomes are attached it is called rough ER and smooth ER when there are no ribosomes attached. The rough endoplasmic reticulum is where most protein synthesis occurs in the cell. The function of the smooth endoplasmic reticulum is to synthesize lipids in the cell. The smooth ER also helps in the detoxification of harmful substances in the cell.

Golgi complex

It is the organelle in the cell that is responsible for sorting and correctly shipping the proteins produced in the ER. Just like our postal packages, which should have a correct shipping address, the proteins produced in the ER should be correctly sent to their respective address. It is a very important step in protein synthesis. If the Golgi complex makes a mistake in shipping the proteins to the right address, certain functions in the cell may stop.

Prokaryote

No Nucleus Single Circular DNA strand DNA area called nucleiod no membrane bound organelles such as mitochondria, vesicles, golgi, rough/ smooth ER Smaller & less complex

Vacuole

Plant cells have what looks like a very large empty space in the middle. This space is called the vacuole. Don't be fooled, the vacuole contains large amounts of water and stores other important materials such as sugars, ions and pigments.

Nucleolus

Responsible for making ribosomes.

Plasma membrane

The membrane enclosing a cell is made up of two lipid layers called a "bilipid" membrane. The lipids that are present in the plasma membrane are called "phospholipids."

Nucleus

The nucleus is the control center of the cell. It is the largest organelle in the cell and it contains the DNA of the cell.

Centrioles

These are found only in animal cells and come into action when the cells divide, helping with the organization of chromosomes.

Mitochondria

This is the cell's powerhouse. This organelle packages the energy from the food you eat into ATP molecules.

Chloroplast

This is the organelle in which photosynthesis takes place. In this organelle the light energy of the sun is converted into chemical energy. Chloroplasts are found only in plant cells not animal cells.

Vesicles

This term literally means "small vessel". This organelle helps store and transport products produced by the cell. The vesicles are the transport and delivery vehicles like our mail and Federal Express trucks. Some vesicles deliver materials to parts of the cell and others transport materials outside the cell in a process called exocytosis.

Lysosomes

Created by the Golgi apparatus, these help break down large molecules into smaller pieces that the cell can use.

Cytoskeleton

Made up of filaments and tubules, it helps shape and support the cell. It also helps move things move around in the cell. For artistic purposes, the cytoskeleton is shown in just one place when in reality it is found throughout the entire cell.

Eukaryote

Mean "True nucleus" Have specialized, membrane bounded organelles Linear DNA More Complex and Larger

Ribosomes

Organelles that help in the synthesis of proteins. Ribosomes are made up of two parts, called subunits.Some ribosomes are found in the cytoplasm, but most are attached to the endoplasmic reticulum. While attached to the ER, ribosomes make proteins that the cell needs and also ones to be exported from the cell for work elsewhere in the body.