Cells Unit

Cells Unit Outline What does it take to be alive? There are 6 criteria for something to be considered “living.” Each of the criteria will be a different part of the notes. Our cell notes will have the following six parts: 1. All living things are made of cells. There is nothing smaller than 1 cell. 2. Living things must be organized. There is structure inside an organism, even if the organism is only made of 1 cell. The different parts of a living thing all have specific jobs to do. 3. Living things must interact with their environment. All living organisms maintain the conditions they need to stay alive within their cells as long as they can, by taking in materials from their environment or by removing wastes from inside themselves.

Outline Con’d All living things somehow use energy. Some organisms can produce their own food, such as plants. Other organisms must obtain food or energy from their environment. Living things must grow and develop. The smallest creature begins tiny and gets just a little bigger. Large, multi-celled creatures may go through life stages as they mature. All living things need to reproduce. Don’t laugh! From bacteria to people, new generations must be made in order for a species to survive. During the course of this unit, we will explore each of these six criteria. Each section of the unit will focus on these numbers, in order! It is important to investigate each area of what makes us “alive.”

Cell Notes Part 1 and 2 All living things are made of Cells. The idea that all living things are made of cells is known as cell theory. There are 3 parts of the cell theory: 1. All organisms are made up of one or more cells. 2. The cell is the basic unit of all organization inside an organism. 3. All cells must be made from cells.

Living things must be organized. There are 2 kinds of cells: Some cells have no membrane-bound structures inside. These cells are called Prokaryotic. 2.Some cells do have structures with membranes inside. These cells are Eukaryotic.

Eukaryotic Cell Prokaryotic Cell

Parts of the cell The organized pieces inside a single cell are called organelles. All cells have organelles, and each one of these organelles has a job to do. A organelles helps cells regulate what comes into a cell or what leaves a cell. All cells have a cell membrane. These membranes also keep the insides of the cell from spilling out. All cells also have cytoplasm. This is a jelly-like substance that surrounds all of the other cell parts. Some types of cells, like plants, algae, fungi, and most bacteria, have a cell wall. These help protect a cell and give it shape. Cells with cell walls have their cell membrane right inside the cell wall.

More parts… The nucleus is the brain of the cell, and is where DNA is kept. This important genetic information holds all of the instructions for how the cell should function. The nucleus is surrounded by the nuclear membrane, which controls the substances that may enter or leave the nucleus. Plant cells can make their own food with structures called chloroplasts. These structures have green pigments inside them called chlorophyll. With these, a plant can capture light energy and use it to make food for itself. Animals do not have chloroplasts.

More parts… All cells have mitochondria, which help the cell obtain energy. Almost all cell parts are made of protein, and the ribosomes inside a cell help make proteins for that cell. The endoplasmic reticulum, or ER for short, helps a cell move materials around inside itself. In order to get materials all over the cell, the ER often extends from the nucleus, all around the cell, all the way to the cell membrane.

Even more parts… With all these items moving around the cells, there must be some way to sort things out. The gogli bodies of a cell sort out proteins and other molecules, and package them up to be moved to other parts of the cell. In some cases, there are more molecules inside a cell than the cell needs to support itself. All cells have storage areas called vacuoles. In these areas, cells can store food, water, waste products, or proteins to build organelles. It’s sad, but sometimes cells or parts of cells die or need to be replaced. The lysosomes of a cell are like its recycling plant. Lysosomes help cells break down when they die or help cells break down only parts of their organelles for fixing.

The cell membrane is like the shipping and receiving part of a factory- regulating what enters and exits.

Cytoplasm is a jelly-like substance that supports the organelles. It is like the inside of a factory building (factory floor)-where everything is located.

The cell wall surrounds the cell membrane in a plant cell- giving it support and protection It is similar to the outside walls of a factory building.

The nucleus is the brain of the cell and controls the cells functions. It is similar to the manager (CEO) in the factory building.

The mitochondria and chloroplast are the powerhouse of the cell The mitochondria and chloroplast are the powerhouse of the cell. It is where the cells energy comes from. It is similar to the machines (power plant) in a factory.

Ribosome’s are responsible for making proteins. They are similar to the workers in a factory. Endoplasmic reticulum serves as a passageway through the cytoplasm and a work station for the ribosome’s. It is similar to a conveyor belt in a factory.

Lysosome’s help cells break down when they die or fix parts that need fixing. Lysosome’s are similar to the maintenance crew in a factory. The golgi body sorts out proteins and other molecules and packages them up to be moved to other parts of the cell. Golgi body is like the finishing and packaging department in a factory

Vacuoles are the storage places for the cell- they store food, water, waste products, and proteins. Vacuoles are similar to storage rooms in a factory.

Cell organization… Multi-cell organisms are organized even more than single-cell organisms. In larger living things, similar cells with the same function are put together. A group of cells that work together to do one job form a tissue. Each cell in a tissue does its part to keep the tissue alive. Tissues are organized into organs. An organ is a structure made of 2 or more types of tissues that work together. When organs work together they form an organ system. Example: A cell from the heart works with another cell from the heart to make heart, or cardiac tissue. Heart muscle tissue works with nerve tissue and blood tissue to make the heart pump. The heart organ works with your veins and your arteries to make up your cardiovascular system.

Organs form organ systems Tissues form organs Cells form tissues Organs form organ systems