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Select All Microscopy to physically look at cells and to find things in a cell Magnification ratio between the size of an image produced by a microscope and its actual size resolution clarity - ability to observe two adjacent objects as distint from one another contrast ability to distinguish different structures, can be enhanced using dyes unaided human eye what you would use to look at a fish egg, bird egg, human height ( objects ranging from approx 0.5 cm to 10 m and larger) light microscope what you would use to look at mitochondria, most bacteria, nucleus, most plant and animal cells. http://farm7.staticflickr.com/6175/6269272638_664bdc97b9.jpg electron microscope what you would used to look at lipids, proteins, ribosomes, viruses, smallest bacteria, plus everything the light microscope can look at light microscope this microscope uses light for illumination, resolution is 0.2 µm electron microscope this microscope uses electron beam, resolution 2nm transmission electron microscopy thin slices stained with heavy metals, some electrons are scattered while others pass through to form an image http://farm4.staticflickr.com/3540/3660656630_8fee8f8d8f.jpg scanning electron microscopy sample coated with heavy metal, beam scans surface to make 3D image http://farm4.staticflickr.com/3327/3276522941_46bd58543f.jpg prokaryotic cells simple cell structure, lack membrane-enclosed nucleus, 2 categories - bacteria and archaea - both are small. there is internal organization but not at the level of complexity as of eukaryotic cells http://farm5.staticflickr.com/4080/4882443506_72d0326bb4.jpg bacteria this is a type of prokaryotic cell that are abundant and most are not harmful http://farm3.staticflickr.com/2416/2234750993_66e2a59f4d.jpg archaea this is a type of prokaryotic cell that is less common and often found in extreme environments. Bacteria this prokaryotic cell has a plasma membrane, cytoplasm nucleoide and ribosomes. in this cell many structures are located outside the plasma membrane, cell wall, glycocalyx, appendages nucleoide region where genetic material is found cell wall support and protection in cell glycocalyx this traps water, and offers protection in a prokaryotic cell - outer gelatinous cover appendages pilli (attachment), flagella (locomotion) ribosomes involved in protein synthesis cytoplasm contained inside plasma membrane, site of metabolism plasma membrane barrier that encloses cytoplasm pilli allow bacteria to attach to surfaces and to each other flagella allow certain bacteria to swim eukaryotic cells much larger than other cells, this type of cell has DNA inside nucleus, exhibit compartmentalization, contains organelles. the shape, size, and organization of cells vary considerable among different species and even among different cell types of the same species organelle membrane-bounded compartment with its own unique structure and function http://farm6.staticflickr.com/5110/5681403651_7e679da37e.jpg centrosome site where microtubules grow and centrioles are found rough endoplasmic reticulum site of protein sorting and secretion smooth endoplasmic reticulum site of detoxification and lipid synthesis mitochondrion site of ATP synthesis cytoskeleton protein filaments that provide shape and aid in movement peroxisome site where hydrogen peroxide and other harmful molecules are broken down golgi apparatus site of modification, sorting, and secretion of lipids and proteins. cytosol site of many metabolic pathways plasma membrane selective movement of substances into and out of the cell, site of cell signalling chromatin a complex of protein and DNA nucleolus site for ribosome assembly lysosome site where macromolecules are digested nuclear envelope double membrane that encloses the nucleus nucleus area where genetic material is organized and expressed nuclear pore passageway for molecules into and out of the nucleus proteome this determines the characteristics of a cell. a single organism can produce different types of cells because there is identical DNA in different cells, but different _________ proteome this determines the structure and function of a cell proteome gene regulation, amount of protein, amino acid sequence of a particular protein and protein modification can influence a cell's ______ differ proteomes in healthy cells _____ from proteomes of cancerous cells cytosol this surrounds the organelles but inside the plasma membrane, cytoplasm includes everything inside plasma membrane. this is the environment surrounding organelles cytosol this is the central coordinating region for many metabolic activities of eukaryotic cells catabolism breakdown of a molecule into smaller components anabolism synthesis of cellular molecules and macromolecules Translation process of polypeptide synthesis. information within a gene is ultimately translated into the sequence of amino acids in a polypeptide. tRNA and mRNA are involved ribosome site of protein synthesis tRNA this transfers amino acids mRNA this carries info to make polypeptide mRNA a ribosome moves relative to an _____ molecule allowing tRNA with specific amino acids to bind. cytoskeleton these proteins are critical for cell function, mutations often lead to desease. this is a network of three different types of protein filaments, microtubules, intermediate filaments, actin filaments microtubules (tubulin) dynamic instability, centrosome or microtubule-organizing center in animals. its tubule wall composed of the protein tubulin. its involved in cell shape, organization of cell organelles, chromosome sorting in cell division, intracellular movement of cargo, cell motility (cilia and flagella) intermediate filaments tend to be more stable than microtubules and actin filaments, which readily polymerize and depolymerize. this can be composed of different proteins, including desmin, keratin, lamin and others, its structure is like twisted filament. its involved in cell shape, provide cells with mechanical strength, anchorage of cell and nuclear membranes. actin filaments also known as microfilaments. it is two intertwined strands composed of the protein actin. its involved in cell shape, cell strength, muscle contraction, intracellular movement of cargo, cell movement, cytokinesis in animal cells motor proteins these proteins use ATP to promote movement. they have three domains called head, hinge and tail. motor this protein moves the cargo along cytoskeleton motor this protein can remain in one place and move filament motor when this protein attempts to walk it exerts a force that causes the filament to bend. (this is because this and filaments are restricted in movement) Flagella this is usually longer than cilia and present singly or in pairs - can propel a cell with whiplike motion cilia this is often shorter than flagella and tend to cover all or part of the surface of a cell flagella and cilia these share the same internal structure, microtubules, dynein (motor protein), and axoneme axoneme the linking protein thats part of the structure of flagella and cilia flagella and cilia their movement involves the propagation of a bend which begins at the base of the structure and proceeds toward the tip flagella can move in single or pairs - example of single is sperm swimming myosin Sheetz and Spudich showed that _______ walks along actin filaments. endomembrane system network of membranes enclosing the nucleus, endoplasmic reticulum, golgi body, lysosomes, vacuoles, peroxisomes - also includes plasma membrane. may be directly connected to each other or pass materials via vesicles nuclear envelope double-membrane structure enclosing nucleus, outer membrane is continuous with the endoplasmic reticulum membrane. materials within nucleus are not part of the endomembrane system nuclear pores passageways through nuclear envelope nucleus primary function involves protection, organization, and expression of the genetic material. ribosome assembly happens here chromosomes composed of DNA and protein, chromatin endoplasmic reticulum network of membranes that form flattened, fluid filled tubules or cisternae cisternae fluid filled tubules that are flattened in endoplasmic reticulum endoplasmic reticulum membrane this membrane encloses a single compartment calles the ER lumen rough endoplasmic reticulum this is the endoplasmic reticulum thats studded with ribosomes. involved in protein synthesis and sorting smooth endoplasmic reticulum this is the endoplasmic reticulum that lacks ribosomes. its involved in detoxification, carbohydrate metabolism, calcium balance, synthesis and modification of lipids golgi body stacks of flattened, membrane-bounded compartments which are not continuous with the endoplasmic reticulum. vesicles transport materials between stacks. this has three overlapping functions; secretion, processing, and protein sorting lysosome these contain acid hydrolases that perform hydrolysis. various acid hydrolases break down proteins, carbs, nucleic acids, and lipids. cite of autophagy autophagy recycling of worn-out organelles through endocytosis lysosome things are sent here so it can lower their pH vacuole functions are extremely varied and differ among cell types and even environmental conditions central vacuoles these are vacuoles in plants for storage and support contractile vacuoles these are vacuoles in protists for expelling excess water. phagocytic vacuoles these are vacuoles in protists and white blood cells for degradation peroxisomes these are relatively small, found in all eukaryotic cells, may be in semiautonomous cells (no one knows for sure) they are a single membrane that encloses a fluid-filled lumen. they contain enzymes to catalyze many different chemical reactions. they break down molecules by removing hydrogen or adding oxygen. H₂O₂ a peroxisome breaks down molecules, what is produced in these reactions? catalase peroxisomes contain this enzyme that breaks down H₂O₂ to make water and oxygen gas, avoiding the production of any dangerous free radicals peroxisome vesicles bud from the endoplasmic reticulum and fuse with each other to form a premature _____________. then additional proteins and lipids are imported, maturing the _________. divide mature peroxisomes may ___________ to produce more peroxisomes plasma membrane the boundary between the cell and the extracellular environment. it is selectively permeable. involved in monitoring transport into and out of cell, cell signalling and cell adhesion. if this gets messed up its game over for cell membrane transport plasma membrane proteins are vital to ______________________ cell signalling to survive and adapt to changing conditions, cells must be able to sense changes in their environment and react to them. cells of multicellular organisms also need to communicate with each other, to coordinate activities. the plasma membrane has receptors for _______ ___________ adhesion proteins in the plasma membranes of adjacent cells bind to each other and promote cell-to-cell ___________. this is critical for animal cells to properly interact in a multicellular organism cell adhesion proteins in the plasma membrane of adjacent cells hold the cells together membrane transport proteins in the plasma membrane allow the transport of substances into and out of cells cell signalling an extracellular signal binds to a receptor that activates a signal cascade leading to a cellular response semiautonomous organelles mitochondria, chloroplasts, these can grow and divide and reproduce (binary fission). they are not completely autonomous because they must import molecules from other parts of the cell for their internal components. semiautonomous organelles these have small circular genomes like bacteria semiautonomous organelles these organelles contain DNA that encodes some essential polypeptides mitochondria this semiautonomous organelle has an outer and inner membrane, inter membrane space and mitochondrial matrix. its primar role is to make ATP. http://farm2.staticflickr.com/1253/4726119968_681c20ea7e.jpg mitochondria this produces ATP, is involved in the synthesis, modification, and breakdown of several types of cellular molecules. can generate heat in brown fat cells. mitochondria cells with heavy energy demands like muscle cells will contain more __________ mitochondria, cristae the inner membrane of ___________ is highly invaginated (folded) to from projections called _______ these folds increase the surface area of the inner membrane, which is the site where ATP is made inner membrane this is the part of the mitochondria where ATP is produced Chloroplasts these are the semiautonomous organelles involved in photosynthesis. these are found in nearly all species of plant and algae. they have and outer and inner membrane with an inter-membrane space. it also has a third membrane. they contain chlorophyl http://farm4.staticflickr.com/3658/3660656618_b41d503061.jpg photosynthesis capture light energy to synthesize organic molecules such as glucose thylakoid membrane this is the third membrane of a chloroplast. it forms flattened tubules that stack to form a granum stroma this is the compartment of the chloroplast that is inside the inner membrane but outside thylakoid membrane. plastids chloroplasts are a specialized version of plant organelles that are generally known as ______. they are derived from unspecialized proplastids.