Lecture 4

Question 1

what is my mnemonic for what a cell must do

Answer 1

MORGC

Question 2

What do the letters of MORGC mean

Answer 2

Make cell materials
Obtain raw materials
Remove waste
Generate required energy
Control all above

Question 3

What features do all cells share

Answer 3

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

Question 4

What organellse does the endomembrane system include

Answer 4

The nuclear envelope, smooth endoplasmic reticulum, rough endoplasmic reticulum, vesicles, golgi apparatus and the plasma membrane

Question 5

what relates all the endoplasmic system

Answer 5

they are all membrane bound organelles so the vesicles secreted can move simply into and out of the organelles.

Question 6

Whats a glycoprotein

Answer 6

a protein with many carbohydrates bonded to it

Question 7

what roles do the endoplasmic system perform

Answer 7

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.

Question 8

Roles of the Smooth endoplasmic reticulum

Answer 8

Lipid synthesis, metabolism of carbohydrates, detoxification of drugs, and calcium ion storage.

Question 9

how does the sER differ from the RER

Answer 9

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

Question 10

role of the rough endoplasmic reticulum

Answer 10

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

Question 11

role of golgi apparatus

Answer 11

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

Question 12

vesicle role

Answer 12

to connect all parts of the endoplamsic system, delievering proteins and other material to each part.

Question 13

what is a lysosome and its role

Answer 13

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.

Question 14

whats a vacuole

Answer 14

a vacuole is a large vesicle often containing cellular nutrients or material it can use

Question 15

what is autophagy

Answer 15

the lysosome eating materials within the cell.

Question 16

what is bulk transport

Answer 16

the transport of large molecules that cannot fit across the plasma membrane proteins.

Question 17

whats exocytosis

Answer 17

The cell secreting certain molecules by fusion of vesicles to the plasma membrane and releasing them outside of the cell is exocytosis.

Question 18

what is endocytosis

Answer 18

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

Question 19

what is phagocytosis

Answer 19

“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

Question 20

what is pinocytosis

Answer 20

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.

Question 21

what is Receptor mediated endocytosis

Answer 21

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.

Question 22

what is the role of the smooth endoplasmic reticulum

Answer 22

metabolism of carbohydrates, lipid synthesis, detoxification of drugs, store calcium ions.

Question 23

the golgi apparatus glycolyses proteins what will it also do

Answer 23

it can also make polysaccharides that are secreted by cell, things like hemicellulose and pectin,

Question 24

what are the tags on the vesicle and what do they do

Answer 24

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

Question 25

how do constitutive and regulated exocytosis differ

Answer 25

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.

Question 26

lysosomes are made by who?

Answer 26

the rough endoplasmic reticulum and the golgi body

Question 27

what is autophagy

Answer 27

an important process where the lysosomes digest the old and redundant organelles in the cell, this is important for cell death.

Question 28

in humans phagocytosis only occurs in

Answer 28

macrophages