cellular anatomy #1 M1 V2

Question 1

cellular function - how does it do that

Answer 1

• membrane separates it from outside world

- membranes within the cell form separate compartments these compartments are called organelles

Question 2

organelles

Answer 2

provide the right conditions for processes, separate things, allow concentration gradients, many different types

Question 3

membranes

Answer 3

semi - permeable barrier - controlled movement of a range of molecules

Question 4

outer cell membrane

Answer 4

the outer cell membrane is a phospholipid bilayer

• this is hydrophobic (repels water)

Question 5

what is the outer cell membrane composed of

Answer 5

• the outer cell membrane is composed of phosphate groups and fatty acids - the composition can change the fluidity
• the membrane also includes proteins for functions

Question 6

what does cholesterol do

Answer 6

cholesterol reduces the fluidity at moderate temperatures, increases when its cold

Question 7

types of cell transport

Answer 7

1. active transport

2. passive transport

Question 8

passive transport

Answer 8

movement of molecules down their concentration gradient (requires no energy)

Question 9

active transport

Answer 9

movement of molecules up / against their concentration gradient, (requires energy) - involves ATP and pumps

Question 10

regular diffusion

Answer 10

• is passive transport
• lipid soluble /hydrophobic can diffuse
• water / glucose / ions cant

Question 11

facilitated diffusion

Answer 11

• is passive transport
• requires “helper” membrane proteins
• water/ glucose/ ions move through channel proteins (“holes” in the membrane)_
• these channels could be gated by charge or chemicals, but still no energy involved

Question 12

active transport

Answer 12

1. direct - directly uses ATP as energy to move molecules up their gradient
2. indirect - uses the energy gained as other molecules move down their gradient to power the transport
   
   • if this is done in the same channel (eg sucrose H+ cotransporter) this is called cotransport
3. effective cell transport is essential for all functions

Question 13

membrane proteins are involved in ?

Answer 13

• signal transduction
• recognizing other cells
• joining cells together
• linking the inside of the cell to the outside

(think signal , recognize , join , link)

Question 14

endomembrane system

Answer 14

system of membranes within a cell

• maintains the separation between compartments
• processes material inside the cell

Question 15

what does the endomembrane system include

Answer 15

The endomembrane system includes

• the SMOOTH and ROUGH endoplasmic reticulum (ER)
• and the Golgi body

Question 16

rough ER

Answer 16

rough because of ribosomes (make proteins)

• makes proteins for the membrane and for secretion
• proteins in the cytoplasm are made elsewhere

Question 17

smooth ER

Answer 17

• No ribosomes
• does everything else (lots of processing)
  
  • detoxification
  • makes membrane lipids
  • metabolises carbohydrates
  • stores calcium
• the amount of the smooth ER can be changed to fit the demands of these processes

Question 18

Golgi complex

Answer 18

• Lot of membrane sacs and vesicles

- processes and packages proteins

Question 19

what are the two sides of the Golgi complex

Answer 19

The Golgi complex had two sides

1. vesicles from ER arrive at the cis side
2. processed vesicles leave at the trans side

Question 20

Type of Golgi complex packaging

Answer 20

• Glycosylates proteins (adds carbs) - important for specific function

Question 21

Type of Golgi complex process

Answer 21

• the Golgi complex can add markers to identify and sort into vesicles
• adds tags to direct those vesicles to compartments
  - retrieval tag directs back

Question 22

what is exocytosis

Answer 22

• transport out of cell via vesicles (not across the membrane)
• can deliver to surface of cell (non secretory) - membrane protein ect
• regulated - hormones and neurotransmitters

Question 23

what is endocystosis

Answer 23

• like exocytosis, but INTO the cell

Question 24

what are the 2 different types of endocytosis

Answer 24

1. Phagocytosis - “food” particles into vacuole which is digested
2. Pinocytosis - solutes, non selective

Question 25

receptor mediated endocytosis

Answer 25

is a way of saying there is a type of endocytosis that is specific, - specific molecules target specific receptors which causes endocytosis for those molecules only.

Question 26

where does the material go into in endocytosis

Answer 26

material goes into Lysosomes - contains enzymes which break down and digest