Lecture 4 Flashcards
what is my mnemonic for what a cell must do
MORGC
What do the letters of MORGC mean
Make cell materials
Obtain raw materials
Remove waste
Generate required energy
Control all above
What features do all cells share
All bound by a selective barrier called the plasma membrane.
Inside all cells is a semifluid, a jelly-like substance called cytosol, in which subcellular components are held
All cells contain chromosomes
All cells have ribosomes, which make proteins according to instructions from genes
What organellse does the endomembrane system include
The nuclear envelope, smooth endoplasmic reticulum, rough endoplasmic reticulum, vesicles, golgi apparatus and the plasma membrane
what relates all the endoplasmic system
they are all membrane bound organelles so the vesicles secreted can move simply into and out of the organelles.
Whats a glycoprotein
a protein with many carbohydrates bonded to it
what roles do the endoplasmic system perform
synthesis of proteins, transport of proteins into membranes or organelles or out of the cell, metabolism and the movement of lipids, and the detoxification of poisons.
Roles of the Smooth endoplasmic reticulum
Lipid synthesis, metabolism of carbohydrates, detoxification of drugs, and calcium ion storage.
how does the sER differ from the RER
the sER and rER perform different roles, but the physical different of the two is that the rough appearance of the rER is due to ribosomes on the surface
role of the rough endoplasmic reticulum
the rER makes proteins in the ribosomes. the proteins synthesised in the proteins enter the lumen of the rER and from their stay in the rER or get transported in a vesicle to the golgi apparatus
role of golgi apparatus
golgi is a polar membraneous organelle, which means it has two sides. The proteins from the rER come into the cis face where they are glycolysed. the proteins are then tagged to sort them into the right vesicle, so they go to the correct location. The vesicles are also tagged for the same reason
vesicle role
to connect all parts of the endoplamsic system, delievering proteins and other material to each part.
what is a lysosome and its role
a membrane sac of hydrolitic enzymes. Lysosomes fuse with endocytosis vacuoles and digest the material inside and release the raw material for the cell to use. The lysosomes also digest old organelles in the cell, recycling their material, also destroying the organelles so the cell can die.
whats a vacuole
a vacuole is a large vesicle often containing cellular nutrients or material it can use
what is autophagy
the lysosome eating materials within the cell.
what is bulk transport
the transport of large molecules that cannot fit across the plasma membrane proteins.
whats exocytosis
The cell secreting certain molecules by fusion of vesicles to the plasma membrane and releasing them outside of the cell is exocytosis.
what is endocytosis
When the cell takes in material and matter by forming new vesicles from the plasma membrane. Like reverse exocytosis. A pocket in the plasma membrane forms then deepens to form a vesicle containing material from outside the cell, which buds off of the plasma membrane
what is phagocytosis
“Cell eating”
The uptake of food particles, food particles are too big to fit through membrane proteins. These food particles enter the cell in food vacuoles and these food vacuoles are engulfed by macrophages and digest them. These macrophages are lysosomes
what is pinocytosis
cell drinking. Inner folding of cell membrane take large gulps of ECM, these then form vesicles and bud off. This process is non selective so any and all solutes are taken into the cell. The vesicles are surrounded by coat protein, fuzzy appearance. The non selective uptake allows the vesicle to ingest many proteins, sugars and other solutes.
what is Receptor mediated endocytosis
in this proteins on the plasma act as receptors for only specific solutes. The specification of solutes allows cells to get the specific solutes they need for specific processes.
what is the role of the smooth endoplasmic reticulum
metabolism of carbohydrates, lipid synthesis, detoxification of drugs, store calcium ions.
the golgi apparatus glycolyses proteins what will it also do
it can also make polysaccharides that are secreted by cell, things like hemicellulose and pectin,
what are the tags on the vesicle and what do they do
these are surface membrane proteins on the vesicle, they allow the vesicle to be sent to right place, whether its to lysosome or plasma membrane
how do constitutive and regulated exocytosis differ
constitutive exocytosis, releases the extra cellular proteins as the vesilces form kinda. Regulated exoctosis waits for a signal and will release things like hormones or neurotransmitters.
lysosomes are made by who?
the rough endoplasmic reticulum and the golgi body
what is autophagy
an important process where the lysosomes digest the old and redundant organelles in the cell, this is important for cell death.
in humans phagocytosis only occurs in
macrophages
