Cell Structure

• Cells are the basic building blocks of life and are the smallest unit of life that can replicate independently.
• Animal and plant cells are examples of eukaryotic cells, while bacterial cells are prokaryotic cells.
• Cells contain various subcellular structures known as organelles.
• Both animal and plant cells are surrounded by cell membranes that control which substances can pass in and out of the cell.
• Both types of cells have a nucleus which contains the genetic material or DNA of the cell and controls the activities of the cell.
• Both animal and plant cells are filled with a gel-like substance called cytoplasm where all the other subcellular structures sit and where the chemical reactions take place.
• Both types of cells contain mitochondria whose job is to provide the cells with the energy they need to function.
• Mitochondria break down sugars like glucose in a process called aerobic respiration which releases energy.
• The cell can use ribosomes, which are the site of protein synthesis, to make proteins.
• Both animal and plant cells contain ribosomes, but plant cells also have a rigid cell wall made up of cellulose, which provides support and structure to the cell.
• Plant cells contain a permanent vacuole, a big sac that contains cell sap, which the cell can use when it needs to.
• Plant cells also have chloroplasts, where photosynthesis happens, containing a green substance called chlorophyll, which absorbs the light energy needed for photosynthesis and makes plants leaves green.
• Bacteria are prokaryotes and consist of a single prokaryotic cell, making them unicellular organisms like the eukaryotic cells we've seen so far.
• Bacteria have a cell membrane, a cell wall, ribosomes, and cytoplasm, but they don't have mitochondria or chloroplasts and their genetic material is not kept in a nucleus, instead it's in a single circular strand of dna that floats around the cytoplasm and contains all the genes they need to survive and reproduce.
• Some bacteria have additional small rings of dna called plasmids, which carry extra genes like antibiotic resistance, which they don't need on a daily basis but may sometimes come in handy.
• Some bacteria have flagella, thread-like structures that protrude out from the bacteria and rotate to propel the bacteria along, allowing them to move around.