ap bio unit 2b (the endomembrane system)

what are the members of the endomembrane system?

nuclear envelope, endoplasmic reticulum, golgi apparatus, lysosomes, vacuoles, plasma membrane

what is chitin?

structural polysaccharide used by arthropods for exoskeletons & by fungi for cell walls

what is peptidoglycan

polymer made of sugars and amino acids that form the cell wall of bacteria

what is cellulose

structural polysaccharide in cell wall of plants; made of beta glucose

what is the nucleus?

contains chromatin/chromosomes & nucleolus; has a double membrane w/ pores & nuclear lamina on the inner side of the nucleus

what is the nucleolus?

makes ribosomes from proteins and rRNA

what is the nuclear lamina?

intermediate filaments found in the nucleus membrane

what is the function of ribosomes?

protein synthesis

what are free ribosomes?

found in the cytosol & produce proteins that will function within the cytosol

what are bound ribosomes?

attached to the ER or nuclear envelope and produce proteins that will be exported from the cell or used in lysosomes

what are vesicles?

small membrane bound sacs that transport materials inside the cell and ship them in or out; can pinch off one organelle and fuse w/ another

what is the endoplasmic reticulum made of?

cisternae (membrane enclosed tubules and sacs)

what is the endoplasmic reticulum?

smooth ER & rough ER; found near the nucleus

what is the function of the smooth ER?

makes lipids, metabolizes carbs, breaks down drugs & poisons, & allows muscles to move

what is the function of the rough ER?

protein synthesis for shipment outside the cell, glycosylation, makes hydrolytic enzymes

what is glycosylation?

when oligosaccharides are added to a protein/lipid (name tag)

phospholipids

two fatty acids + one glycerol molecule that makes up the cell membrane; hydrophilic head and two hydrophobic tails

what makes up the cell membrane?

a lipid bilayer, proteins, cholesterol, and carbohydrates

what is the Golgi Apparatus?

organelle made of cisternae where proteins and lipids from the ER are modified, stored, & shipped out

what does the golgi apparatus do to the glycoproteins?

changes the oligosaccharides on them (ID)

what does the golgi apparatus make?

makes pectin to connect cell walls

how does the golgi apparatus sort products?

adds phosphates before shipping them out (address)

where is the golgi apparatus cis/trans face?

the cis face is near the ER, the trans face is towards the membrane

what do the faces of the golgi do?

cis face receives, trans face ships

what are oligosaccharides?

carb sugar chains that attach to glycoproteins and act as name tags that allow cells to recognize each other

what is pectin?

made by the golgi to connect cell walls

what are lysosomes?

membrane bound sacs of hydrolytic enzymes used to break things down

what is the pH of lysosomes?

pH of 5 maintained by pumping H+ ions into the lumen of the lysosome

how are lysosomes made?

ribosomes on ER make hydrolytic enzymes -> golgi trans face wraps in vesicles

what are hydrolases?

hydrolytic enzymes

what is lumen?

the membrane enclosed fluid space of a lysosome OR a thylakoid

what is autophagy?

recycles cells by breaking down damaged cell parts and macromolecules using lysosomes

lysosomes are NOT FOUND where?

in plant cells

what are vacuoles?

storage area for plant cells

what type of membrane does a central vacuole have?

has a membrane called the tonoplast that surrounds it; is filled with cell sap

how do vacuoles affect cell growth?

they allow cells to grow larger with minimal cytoplasm investment