Cell theory organisms are composed of 1+ cells, which are the smallest unit of life, which come from pre-existing cells What do Prokaryotic Cells have? - Cell wall - Plasma Cell membrane -Flagella -Ribosomes -Nucleoid Cell Wall made of of carb protein complex, PEPTIOGLYCAN, allows for cell to hold shape Plasma Membrane Controls movement of materials in and out of cells, plays role in binary fission Cytoplasm -occupies interior, no compartmentalization, site of all chemical processes in the cell -Region where organelles can be found Capsule some, not all have this, made of polysaccharide, sticky and allows for attachment to surfaces Pili short hair growth on cell wall, used for attachment, joins bacteria cells to prep for DNA transfer Flagella longer than pili, used for movement Ribosomes where protein synthesis occurs, in big numbers in cells that require high protein content Nucleoid Region non-compartmentalization and has a single long thread of DNA, controls cells and reproduction Plasmids small circular DNA molecules, not connected to main loop Binary Fission the simple cell division, process where DNA is copied and the daughter chromosomes become attached to different regions on the membrane, cell elongates and divides into 2 identical daughter cells Microscope DOs -careful -proper carrying -using for intended purpose Microscope Don'ts -squinting -carrying with one hand -using coarse focus knob on high power -leaving at edge of lab bench Characteristics of Prokaryotic Cells -DNA is circular, not enclosed -Free DNA -Non-membrane bound organelles -70s ribosomes -Very small -Division by binary fission SURFACE AREA TO VOLUME RATIO does what? What does this do? Limits cell size, the bigger this ratio, the more efficient it is for the diffusion to take place in and out of the cell. Differentiation process whereby cells develop into specific cells as a result of the expression of certain genes but not others What are stem cells? Cells that retain their ability to divide into various types of cells. What type of tissue in plants contains stem cells? Meristematic tissue. Where are stem cells found in animals? In embryos. Cytosol Fluid portion of cytoplasm What is the endoplasmic reticulum? An extensive network of tubules and channels that extends almost everywhere from the nucleus to the plasma membrane. What is the function of the endoplasmic reticulum? Transports materials throughout the internal region of the cell. Rough ER has ribosomes on its surface and is therefore involved in protein development and transport. Smooth ER lacks ribosomes on its exterior but contains unique enzymes embedded on its surface. 6 functions of the smooth ER 1. production of membrane phospholipids and cellular lipids 2. Production of sex hormones such as testosterone and estrogen 3. Detoxification of drugs in the liver 4. Storage of calcium ions needed for contraction in muscle cells 5. Transportation of lipid-based compounds 6. Aid the liver in releasing glucose into the bloodstream when needed What are ribosomes? Structures that have no exterior membrane What is the primary function of ribosomes? Carry out protein synthesis What are ribosomes composed of? A type of RNA and a protein How many subunits do ribosomes have? Two subunits What are lysosomes? Intracellular digestive organelles that arise from the Golgi apparatus. What do lysosomes catalyze the breakdown of? Proteins, nucleic acids, lipids, and carbohydrates. Golgi apparatus Responsible for the collection, packaging, modification, and distribution of materials synthesized in the cell Two sides : cis and trans cisternae Golgi apparatus is composed of a stack of flattened sacs called this What shape are mitochondria? Rod-shaped What are mitochondria commonly referred to as? The cell's powerhouse Do mitochondria have their own DNA? Yes, it is similar to that of bacterial cells What type of membrane do mitochondria have? Double-membraned How is the outer membrane of mitochondria described? Smooth What are the folds in the inner membrane of mitochondria called? Cristae matrix Inside the mitochondria inner membrane is fluid called this What is the function of the cristae in mitochondria? The cristae provide a huge internal surface area for the chemical reactions in the mitochondria to occur. What type of ribosomes do mitochondria produce and contain? Mitochondria produce and contain their own ribosomes. What is the primary energy molecule produced by mitochondria? ATP (adenosine triphosphate). What is the nucleus? A compartmentalized region where DNA can be found. What is the nuclear envelope? A double membrane that covers the nucleus. What do the pores in the nuclear envelope allow? Communication with the cell's cytoplasm. What are chloroplasts? Organelles that can only be found in algae and plant cells. What type of membrane do chloroplasts have? Double-membraned. What unique genetic material do chloroplasts contain? Their own ribosomes and DNA in the form of a ring. What structures are found in the interior of chloroplasts? Grana, thylakoids, and the stroma. Granum made up of a stack of thylakoids Thylakoids flattened membrane sacs with components essential for the absorption of light Stroma similar to cytosol; contains many enzymes and chemicals essential to complete the process of photosynthesis What is a centrosome? A structure that consists of a pair of centrioles at right angles to one another. What is the function of centrioles in the centrosome? They are involved in assembling the microtubules necessary for providing structure and movement in the cell. Why are microtubules important for cells? They are necessary for cell division. In which types of cells are centrosomes found? Centrosomes are found in animal, fungal, and most protoctist cells, but not in higher plant cells. What are vacuoles? Storage organelles that usually arise from the Golgi apparatus. What substances do vacuoles store? Potential food, metabolic wastes and toxins, and water. How do vacuoles affect cell size? They allow cells to have a higher surface area to volume ratio even at larger sizes. What role do vacuoles play in plant cells? They allow the uptake of water to provide rigidity to the cell.
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