Microscope cell images Animal cells All living things are made up of one or more cells. Cells are the basic units of structure and function in organisms. All cells come from existing cells. Cells of the same type that are grouped together form a tissue. A tissue is a group of the same sort of cells, all working together to do a job. Electron microscope image of an animal cell. Mitochondria- the “powerhouse” of the cell, this structure harvests energy from organic material. Muscles use a lot of energy- so a muscle cell has to have numerous mitochondria. (Mitochondria is the plural – a single one is a mitochondrion) Mitochondria are about the size of a bacterial cell. This is an electron microscope image of a ribosome, magnified 1000’s of times. Ribosomes –are drawn as little balls either floating in the cytoplasm or they can be found attached to a larger structure called the rough endoplasmic reticulum (you don’t need to remember that one!). The job of the ribosomes is to synthesize (make) proteins. Image of muscle cells. Muscle cells are able to change length, they need lots of energy to do this. A nerve cell (neuron) can be very long so that signals can be carried around the body very quickly (> 400km/h). Sperm cells are packed full of mitochondria. Plant cells Plant cells differ from animal cells by having additional organelles. Plant cells have chloroplasts that converts sunlight into energy Plant Cells have a cell wall that is a thicker outer coating that helps maintain the shape of the cell and protects it from damage (this makes our lettuce crunchy) The cell wall is made of cellulose. Plant cells have central vacuoles (sacs) that contains a watery liquid called cell sap, which aids structure of the plant. Bacterial cells flagellum Bacteria are found everywhere including our surrounding environment and inside our bodies. Bacterium is a primeval form of life and can be unicellular or a single celled micro-organism. Bacteria can only been seen through a microscope as they are so tiny that they exceed no more than a few micrometres in length. The shape of bacteria differs and can be found in the form of a rod, sphere or spiral. As bacteria do not have a nucleus, they possess a single circular DNA chromosome that is located within the cytoplasm of the cell. There is no sexual interaction and bacteria multiply by binary fission. Depending on circumstances, bacteria may or may not cause disease. As long as a bacterium does not over populate or colonize a specific area in the body, it is unlikely you will suffer a disease. Studies have proven that there are more bacterial cells than human cells in the body, with most of them situated in the skin and digestive tract. Fungal cells Yeast cells are a very common fungal cell. They vary in size, but are usually about 4 thousandths of a millimeter (4 microns) in diameter, too small to see without a microscope. Yeast are one-celled creatures that eat starches and sugars. Enzymes inside the mitochondria in the yeast cells use oxygen to break up the food molecules into smaller molecules and let out some energy for the cell to power itself. This process also makes some carbon dioxide molecules, and the yeast cell considers the carbon dioxide molecules to be waste, puts them in vacuoles, and gets rid of them through the cell membrane. Candida Albicans is a yeast that normally lives in our intestinal and vaginal tracts, along with friendly or good bacteria. Yeast helps good bacteria grow, as long as the good bacteria is there in sufficient numbers and has the advantage in numbers. It’s excessive growth creates an imbalance in multiple systems in the body that is called candida. Frequent use of antibiotics is considered the main contributor to bad bacteria and the weakening of the intestinal wall, subsequently causing candida Magnification : x1,000