* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Plant and Animal Cell
Survey
Document related concepts
Tissue engineering wikipedia , lookup
Biochemical switches in the cell cycle wikipedia , lookup
Cytoplasmic streaming wikipedia , lookup
Cell nucleus wikipedia , lookup
Signal transduction wikipedia , lookup
Cell encapsulation wikipedia , lookup
Cell membrane wikipedia , lookup
Extracellular matrix wikipedia , lookup
Programmed cell death wikipedia , lookup
Cellular differentiation wikipedia , lookup
Cell culture wikipedia , lookup
Cell growth wikipedia , lookup
Organ-on-a-chip wikipedia , lookup
Cytokinesis wikipedia , lookup
Transcript
Cell Nucleus - Commanding the Cell The cell nucleus acts like the brain of the cell It helps control eating, movement, and reproduction The nucleus is not always in the center of the cell It will be a big dark spot somewhere in the middle of all of the cytoplasm (cytosol) You probably won't find it near the edge of a cell because that might be a dangerous place for the nucleus to be Cell Wall Cell wall structure showing membrane and cell wall in a plant Cell membranes surround every cell you will study Cell walls made of cellulose are only found around plant cells and a few other organisms Cellulose is a specialized sugar that is classified as a structural carbohydrate and not used for energy. If a plant cell is like a water balloon, the cell wall is like a cardboard box that protects the balloon. While cell walls protect the cells, they also allow plants to grow to great heights You have a skeleton to hold you up. A 100-foot tall redwood tree does not It uses the strong cell walls to maintain its shape. For overall support, dense cells in the core of the trunk can let a tree grow very high Cell walls are slightly elastic for smaller plants, leaves, and thin branches. Cell Membrane Cell membrane is like a plastic bag According to cell theory, cells are the main unit of organization in biology. Whether you are a single cell or a blue whale with trillions of cells, you are still made of cells All cells are contained by a cell membrane that keeps the pieces inside When you think about a membrane, imagine it is like a big plastic bag with some tiny holes. That bag holds all of the cell pieces and fluids inside the cell and keeps any nasty things outside the cell The holes are there to let some things move in and out of the cell Vacuole Vacuoles are storage bubbles found in cells They are found in both animal and plant cells but are much larger in plant cells Vacuoles might store large amounts of food, water or any variety of nutrients a cell might need to survive They can even store waste products so the rest of the cell is protected from contamination Eventually, those waste products would be sent out of the cell When a plant cell has stopped growing, there is usually one very large vacuole. Sometimes that vacuole can take up more than half of the cell's volume. Vacuoles hold onto things that the cell might need, just like a backpack. Cytoplasm Cytoplasm is the fluid that fills a cell Scientists used to call the fluid protoplasm. Early on, they didn't know about the many different types of fluids in the cell. There is special fluid in the mitochondria, endoplasmic reticulum, Golgi apparatus, and nucleus. The only two 'plasms' left are cytoplasm (cytosol) and nucleoplasm (nucleus) Each of those fluids has a very different composition The cell organelles are suspended in the cytosol The microfilaments and microtubules set up a "skeleton" of the cell and the cytosol fills the spaces The cytoplasm has many different molecules dissolved in solution You'll find enzymes, fatty acids, sugars, and amino acids that are used to keep the cell working. Waste products are also dissolved before they are taken in by vacuoles or sent out of the cell Chloroplast Chloroplasts are the food producers of the cell The organelles are only found in plant cells and some protists such as algae Animal cells do not have chloroplasts Chloroplasts work to convert light energy of the Sun into sugars that can be used by cells The entire process is called photosynthesis It all depends on the little green chlorophyll molecules in each chloroplast The oxygen released by the chloroplasts is the same oxygen you breathe every day. They use oxygen in the process of releasing chemical energy from sugars Endoplasmic Reticulum Another organelle in the cell is the endoplasmic reticulum The ER functions as a manufacturing and packaging system It works closely with the Golgi apparatus, ribososmes, mRNA, and tRNA The endoplasmic reticulum is a network of membranes found throughout the cell and connected to the nucleus The membranes are slightly different from cell to cell and a cell’s function determines the size and structure of the ER For example, some cells, such as prokaryotes or red blood cells, do not have an ER of any kind Cells that synthesize and release a lot of proteins would need a large amount of ER You might look at a cell from the pancreas or liver for good examples of cells with large ER structures. Mitochondrion Mitochondria are known as the powerhouses of the cell They are organelles that act like a digestive system which takes in nutrients, breaks them down, and creates energy rich molecules for the cell The biochemical processes of the cell are known as cellular respiration Many of the reactions involved in cellular respiration happen in the mitochondria Mitochondria are the working organelles that keep the cell full of energy Mitochondria are small organelles floating free throughout the cell Some cells have several thousand mitochondria while others have none Muscle cells need a lot of energy so they have loads of mitochondria. If a cell feels it is not getting enough energy to survive More mitochondria can be created Sometimes a mitochondria can grow larger or combine with other mitochondria It all depends on the needs of the cell lysosome Lysosomes - Little Enzyme Packages You will find organelles called lysosomes in nearly every animal-like eukaryotic cell Lysosomes hold enzymes that were created by the cell The purpose of the lysosome is to digest things They might be used to digest food or break down the cell when it dies A lysosome is basically a specialized vesicle that holds a variety of enzymes The enzyme proteins are first created in the rough endoplasmic reticulum Those proteins are packaged in a vesicle and sent to the Golgi apparatus The Golgi then does its final work to create the digestive enzymes and pinches off a small, very specific vesicle That vesicle is a lysosome From there the lysosomes float in the cytoplasm until they are needed. Lysosomes are single-membrane organelles Golgi body Golgi Apparatus - Packing Things Up The Golgi apparatus or Golgi complex is found in most cells It is another packaging organelle like the endoplasmic reticulum (ER) It was named after Camillo Golgi, an Italian biologist While layers of membranes may look like the rough ER, they have a very different function The Golgi apparatus gathers simple molecules and combines them to make molecules that are more complex It then takes those big molecules, packages them in vesicles, and either stores them for later use or sends them out of the cell It is also the organelle that builds lysosomes (cell digestion machines) Golgi complexes in the plant may also create complex sugars and send them off in secretory vesicles The vesicles are created in the same way the ER does it The vesicles are pinched off the membranes and float through the cell The Golgi apparatus is a series of membranes shaped like pancakes The single membrane is similar to the cell membrane in that it has two layers Lysosome Ribosomes - Protein Construction Teams Cells need to make proteins Enzymes made of proteins are used to help speed up biological processes. Other proteins support cell functions and are found embedded in membranes Proteins even make up most of your hair When a cell needs to make proteins, it looks for ribosomes Ribosomes are the protein builders or the protein synthesizers of the cell They are like construction guys who connect one amino acid at a time and build long chains Every cell needs ribosomes to manufacture proteins Since there are no membrane-bound organelles in prokaryotes, the ribosomes float free in the cytosol Ribosomes are found in many places around a eukaryotic cell You might find them floating in the cytosol Those floating ribosomes make proteins that will be used inside of the cell Other ribosomes are found on the endoplasmic reticulum Endoplasmic reticulum with attached ribosomes is called rough ER. It looks bumpy under a microscope 3 major differences between the plant and animal cell Animal cells do not have chloroplasts Only plant cells have a cell wall Vacuoles are way bigger in plant cells