Ch. 4.1 - Cellular Structure

• genetic control • manufacture and digestion • energy processing • structure support, movement, and communication

nuclear envelope, ER, golgi apparatus, lysosomes, vacuoles, plasma membrane

• smooth or rough • produces enzyme for synthesis of lipids, oils, phospholipids, and steroids • produces enzymes that process drugs, alcohol, toxins, etc • stores Ca+ • manufactures more membranes

• finishes, sorts, and ships cell products • Molecular Warehouse and Processing Station • modifies protein sugars, adds phosphate markers • vesicles that enter GA mature as they cross stacks from receiving to shipping end

• digestion and recycling • are membrane enclosed sac of digestive enzymes • may contain up to 50 different digestive enzymes • have an acidic interior (pH 4.5-5) • involved in membrane repair and cell signalling

• made by rough ER • processed in GA • fuse with food vacuoles and digest food • destroy bacteria • engulfed by white blood cells or fuse with other vesicles containing damaged organelles or other materials

• transport vesicle (contain inactive hydrolytic enzymes) goes to GA • lysosome engulfing damaged organelle or engulfment of particle • food vacuole • digestion

• don’t originate from the endomembrane system (relationship is still unknown) • break down fatty acids in liver and detoxify alcohol with the end product of H2O2 • other enzymes then convert the hydrogen peroxide to water • due to toxicity of the products in peroxisomes = why they’re not part if the regular endomembrane system

• digestion and osmotic regulation • large water containing vesicles • contractile vacuoles help eliminate water • in plants vacuoles love digestive functions, may contain cell pigments or poisons that protect the plant

• double membrane = 2 internal compartments • intermembrane space and mitochondrial matrix • folded inner membrane form cristae • matrix contains mitochondrial DNA, ribosomes and enzymes for cellular respiration

-double outer membrane = 2 internal compartments -intermembrane space and stroma -thylakoids = 3rd membrane - inside of which is the thylakoid space >thylakoids contain chlorophyll

• one theory for how mitochondria and chloroplasts came into existence within eukaryotic cells • endosymbiotic theory states that chloroplasts and mitochondria originated as undigested bacteria in eukaryotic cells

• mitochondria and chloroplasts contain their own DNA and ribosomes, which are more similar to these prokaryotes • they have double membranes - could be explained by phagocytosis • they divide independently from the cell

• provides structural support and functions in cell motility and regulation • composed of 3 basic parts: microfilaments, intermediate filaments, microtubules

• solid rods of mostly actin protein arranged in a twisted double chain • form a 3D network just inside the plasma membrane • support the cells shape and interact with the thicker myosin filaments to cause muscle contraction

• bigger than microfilaments and smaller than microtubules • made from a variety of fibrous proteins that coil together into thicker cables • reinforce cell shoe and anchor certain organelles, like the nucleus

• largest components of the cytoskeleton • made up of tubulin protein (forms a hollow tube) • help maintain cell’s shape and combined with motor proteins act as tracks for organelles to move along within the cell - the transport highway of cells • very important in centrioles, cilia, and flagella

-animal cells excrete an extracellular matrix of glycoproteins and collagen that helps hold tissues together and support the plasma membrane -EM of glycoproteins and collagen may bind to integrin proteins that span the membrane and attach to microfilaments on the inside of the cell

-past 50 years decline in sperm counts and qualirt -phthalates (plasticizers) are hormonally active and mess with sex hormones and sperm quality in rats -several studies show that normal levels of human exposure to phthalates is correlated with lower sperm counts and quality -no dynein protein = primary ciliary dyskinesia >cilia and flagella cannot bend so lungs can’t be cleared and sperm can’t swim

for a tissue to be a tissue, there must be communication between the cells that are a part of it

• tight (very close and “knit” together by proteins) • anchoring (cells riveted together with keratin proteins anchored in the cytoplasm (desmosomes)) • gap (communicating) protein lined pores connect cells allowing ions to flow through

• cell walls of plants must have “holes” in them to allow for intracellular communication in plant tissues • there “holes” are called plasmodesmata or plasmodesma (sing.) • plasma membrane and cytoplasm of the cells extend through the plasmodesmata