FC: Cell Mixbook | Bryce Wilkinson-Perdew Vik Shirvaikar Period 3B PAP Biology 09/29/11
1: The cell theory is one of the basic ideas of biology - it centers on the idea that cells are the basic unit of every living thing. Credit for developing the cell theory is usually given to Matthias Schleiden, Theodor Schwann, and Rudolf Virchow (who will be discussed later). The cell theory consists of three main parts: 1. All living things are made up of cells. 2. Cells are the basic units of living things. 3. All cells arise from pre-existing cells. | Cell Theory | Part 3: All cells arise from pre-existing cells.
2: - Robert Hooke was an English scientist who looked at cork through a microscope and observed tiny room-like structures that reminded him of the cells monks lived in, thus creating the term "cell". - Rudolph Virchow was a German physician who was the first to state that all cells come from pre-existing cells. - Matthias Schleiden was a German botanist who looked at plant parts under a microscope and concluded that plants are made up of cells. - Theodor Schwann was a German biologist who looked at animal parts under a miscroscope and concluded that animals are made up of cells. -Virchow, Schwann, and Schlieden are considered to be the co-creators of the cell theory. | Scientist Contributions | Schlieden and Schwann, who frequently collaborated.
3: Prokaryotic - Have no nucleus, meaning that the DNA in prokaryotes floats freely around the cell. - Have no membrane-bound organelles. - Reproduce through binary fission, or by duplicating genetic material and then splitting into two - Usually found as part of bacteria or archea. | Eukaryotic - Have a nucleus which holds all DNA together. - Have multiple membrane-bound organelles, including vacuoles, ER, lysosomes, mitochondria, etc. - Reproduce through mitosis or meiosis. - Usually found in fungi, plant, or animal cells. | Prokaryotic vs. Eukaryotic Cells
4: Plant Cells - Have chloroplasts - can make their own food - Vacuole is much larger than in animal cells - More complex structure - Have a cell wall for structure as the outer layer - Have a fixed shape - Only lower forms have centrioles | Animal Cells - Have no chloroplasts - cannot make their own food - Usually have vacuoles, but they are much smaller than those found in plant cells. - Simpler structure - Do not have a cell wall - cell membrane is the outer layer - Have an irregular shape - All have centrioles | Plant vs. Animal Cells
5: Ribosomes The ribosomes use the instructions contained within DNA to make proteins (amino acids). They are frequently found on ER. | Golgi Apparatus The Golgi Apparatus's job is to package chemicals and then send them to other cells as well as other places within the cell. | Mitochondria Mitochondria combine sugar with oxygen to produce ATP, the cell's primary energy source. They provide the energy a cell needs to function. | Lysosome The lysosome's job is to "digest" and recycle waste products and debris within the cell. | Endoplasmic Reticulum There are two types of ER - rough and smooth. Rough ER is covered in ribosomes and is used for protein synthesis and the fine-tuning of proteins. Smooth ER has no ribosomes on it and is associated with the production of lipids. | Cell Structures
6: Cell Wall The cell wall provides structure and support to the rest of the cell. It is only found in plant cells. | Cytoplasm The cytoplasm is the thick gel-like substance that holds all the organelles in the cell. It takes up about 70% of most cells' volume. | Central Vacuole The vacuole stores water and waste products. It is the largest organelle in most plant cells but is also found in most animal cells. | Chloroplast Chloroplasts use light energy to make food for plant cells. They are only found in plant cells. | Nucleus The nucleus contains the cell's DNA and also contains the nucleolus, which produces ribosomes. These ribosomes are released from the nucleus through the nuclear pores in the nuclear envelope surrounding the nucleus. | Cell Structures
7: "Homeostasis" is the tendency of the body to maintain a generally stable state. This means that the human body as well as each individual cell will take certain steps in order to maintain overall equilibrium. A cell maintains homeostasis by controlling what materials can pass in and out of it - if there is too much of a certain material inside the cell, the cell will expel some of that material in order to reach the correct level. Likewise, if there is not enough of a certain chemical within the cell, the cell will allow some of that material in in order to compensate. | Cell Membrane | Homeostasis | All cells, prokaryotic and eukaryotic, have a cell membrane. The membrane provides general structure to the cell and separates the inside and outside of the cell from each other. By doing this, the membrane serves as a semi-permeable protective barrier, protecting the organelles on the inside of the cell and controlling what materials can pass in and out of the cell. | The general structure of a cell membrane | Homeostasis - the art of balance