BIOL10004 Lecture Notes - Lecture 4: Glyoxysome, Catalase, Microtubule
28 Jun 2018
School
Department
Course
Professor
LECTURE 4 – EUKARYOTES II – ENDOMEMBRANE SYSTEM & CYTOSKELETON
Endomembrane systems – making, packaging and shipping of proteins system of compartments
includes all membrane-bound components of a cell (including nuclear membrance)
oexcept mitochondria + chloroplasts (b/c semi-autonomous)
Nucleus + ER are physically connected
rER may have formed from invagination of ribosome-bearing plasma membrane around the early
nucleus
Intracellular Membranes
Enclose a space (cistern or vesicle) Never open-ended (unless damaged)
Provide surface for biochemical reactions
Establish a number of compartments to prevent mixing
oImportant for eukaryotes as they do a lot of protein modification
Transport within cell or to adjacent cells
Very fluid due to phospholipids
Endoplasmic reticulum (ER) – heart of endomembrane system (takes up huge interior)
Consists of membranes + cisternae result in internal compartments & channels
oLarge surface of area synthesis of proteins, lipids & carbohydrates
Dynamic – changes in structure & function over time
oi.e. can change from rough to smooth depending on situation
Connected to nucleus
Rough ER = protein synthesis as ribosomes are attached makes more complicated proteins
Smooth ER = makes lipids + hormones + some carbs
oAlso, detoxification role
Breaks down harmful lipids
Golgi apparatus (single membrane)
Flattened stacks of membrane (cistern) called Golgi stacks
Functional extensions of ER and are polar (receives vesicles from ER)
Polar structure one end is diff to another (entry & exit face)
Function: collection, packaging and distribution of molecules synthesised elsewhere in the cell
(lipids, proteins etc)
oCollection of molecules for packaging
oLots of molecules come to mature/modified can stay or be secreted out
oMost polysaccharides are manufactured in Golgi apparatus
Lysosomes – dust bins of animal
Break down ingested materials via autophagy into carbs, proteins, lipids & nucleic acids
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Lecture 4 eukaryotes ii endomembrane system & cytoskeleton. Endomembrane systems making, packaging and shipping of proteins system of compartments includes all membrane-bound components of a cell (including nuclear membrance: except mitochondria + chloroplasts (b/c semi-autonomous) Nucleus + er are physically connected rer may have formed from invagination of ribosome-bearing plasma membrane around the early nucleus. Enclose a space (cistern or vesicle) never open-ended (unless damaged) Establish a number of compartments to prevent mixing: important for eukaryotes as they do a lot of protein modification. Endoplasmic reticulum (er) heart of endomembrane system (takes up huge interior) Consists of membranes + cisternae result in internal compartments & channels: large surface of area synthesis of proteins, lipids & carbohydrates. Dynamic changes in structure & function over time: i. e. can change from rough to smooth depending on situation. Rough er = protein synthesis as ribosomes are attached makes more complicated proteins. Smooth er = makes lipids + hormones + some carbs: also, detoxification role.
