Cell Vocabulary Sections 1.1 - 1.3

All living things or organisms have these characteristics in common: 1. Every living organism is made of one or more cells. 2. All living organisms grow, develop, get older and die. 3. All organisms are sensitive to changes in their environments (smells, motions, sounds, temperatures, etc.) and have ways to respond to the changes they sense. 4. All living things are able to reproduce. 5. All living things can repair and maintain themselves 6. All living things produce waste material. 7. All living things can move.

Needs of Living Things All organisms need energy, materials (food, carbon dioxide, nitrogen, oxygen and water) and living space. All energy used by life on Earth comes from the Sun.

organism An individual living thing, made up of one or many cells, that is capable of growing and reproducing.

Cell Theory All living things are made up of cells. Cells are the smallest working units of all living things. All cells come from pre-existing cells through cell division.

Cell The smallest unit that is able to perform the basic functions of life.

Examples of Cells Amoeba Proteus Plant Stem Bacteria Red Blood Cell Nerve Cell

unicellular A term used to describe an organism that is made up of a single cell. Example: bacteria

Example: animals and plants multicellular A term used to describe an organism that is made up of many cells. Example: animals and plants

There are two major kinds of cells: prokaryotic cells and eukaryotic cells.

prokaryotic cell The prokaryotic cell is the simplest of the two cell types. A cell that lacks a nucleus and other organelles, with DNA that is not organized into chromosomes Example: bacteria

Prokaryotes have no true nucleus Prokaryotes have no true nucleus. Instead, their genetic material is found as circular DNA in the nucleoid region with no nuclear membrane to isolate it from the rest of the cell. Prokaryotes also do not have membrane-bound organelles as do eukaryotes. Prokaryotes have a plasma membrane surrounding the entire cell, and most prokaryotes have a cell wall.

Example: plant or animal cells eukaryotic cell A cell in which the genetic material (DNA) is enclosed within a nucleus, surrounded by its own membrane. Example: plant or animal cells nucleus

organelle A cell structure, enclosed by a membrane that performs a function. Examples: mitochondria, chloroplasts, lysosomes

Organelles found in plant cells Cytoplasm

Organelles found in an animal cell Vacuole Cytoplasm

Surrounding the Cell

cell membrane The outer boundary of the cytoplasm, a layer that controls what enters or leaves the cell. A continuous, almost invisible structure surrounding the cell.

cell wall This outer barrier provides extra support for the cell and gives it a shape. In plants, the cell wall is made mostly of cellulose, a fiber that is the main component of wood and paper.

Inside the Cell

Cytoplasm A thick, gelatin-like material contained within a cell membrane The cell’s environment, which is made mostly of water but also contains salts, dissolve gases, nutrients, and wastes.

Nuclear Membrane Surrounds nucleus Made of two layers Openings allow material to enter and leave nucleus http://library.thinkquest.org/12413/structures.html

Nucleus, nucleolus, and chromosomes The structure in a eukaryotic (plant or animal) cell that contains the genetic material. “Computer” or brain of the cell. It contains the cell's DNA and the cell’s nucleolus, which is the site of ribosome production. Chromosomes hold the DNA which is the genetic material of the cell. The nuclear membrane protects the nucleus and allow materials to pass in and out, except for DNA

mitochondria Organelles that release energy by using oxygen to break down sugar. ”Power station” this is the site where most of the energy metabolism occurs, it releases energy stored in food. This fuels the cell and gives us energy in the form of ATP.

endoplasmic reticulum (E.R.) This is a membrane covered compartment that makes lipids and other materials for use inside and outside the cell. It is also the organelle that breaks down drugs and other chemicals that could damage the cell. The cell’s transportation system

Proteins, the building blocks of all cells, are made up of chemicals known as amino acids. These amino acids are hooked together to make proteins at very small organelles called ribosomes. Ribosomes are the smallest but most abundant organelles. Ribosomes are not covered by a membrane like most other organelles. ribosomes

The cell’s packaging plant golgi bodies The cell organelle that packages and carries proteins in little bubbles that separate and float into the cytoplasm so they may be transported out of the cell. The cell’s packaging plant

The ”garbage disposal” or “recycling center” of the cell lysosomes Lysosomes are a special vesicle in a cell that digest food particles, wastes, cell parts, and foreign invaders. The ”garbage disposal” or “recycling center” of the cell

Vacuole A large membrane covered structure found in plant cells that serves as a storage container for water and other liquids. Also found in animal cells but they are smaller Help plants maintain their shape

Where photosynthesis takes place chloroplasts The food making structures found in plant cells that contain a green pigment called chlorophyll. Chlorophyll captures the energy of sunlight and uses it to drive a chemical reaction that combines water and carbon dioxide to make glucose - a simple sugar that plants use as food. Where photosynthesis takes place

Other important vocabulary terms or concepts related to cells Section 1.3

specialization The specific organization of a cell and its structure that allows it to perform a specific function. Specialized human body cells

Cell The smallest unit that is able to perform the basic functions of life.

tissue A group of similar cells that are organized to do a specific job. Example: human heart tissue

organ A structure in a plant or animal that is made up of different tissues working together to perform a particular function. Example: Human heart

organ system A group of organs that work together to perform a specific function in the body. Example: the human circulatory system

Anything that can independently carry out life processes. organism Anything that can independently carry out life processes. Example : human boy and girl

Organization of life in multicellular organisms tissue cell organ organ systems make up an organism