Lecture 4: Plasma membrane and organelles

Question 1

What does a cell do:

Answer 1

manufacture new material
obtain raw materials
Remove waste
generate required energy

Question 2

seperate compartments with specific conditions are called…

Answer 2

organelles

Question 3

Plasma membrane provides ……

and acts …..

Answer 3

• special conditions with in a cell

- as a semi permeable membrane

Question 4

Organelles provide…

Answer 4

special conditions for specific processes

Question 5

Organelles keep…

Answer 5

incompatible processes apart

Question 6

Organelles allow…

Answer 6

specific substances to be concentrated

Question 7

Organelles form…

Answer 7

concentration gradients

Question 8

Organelles package…

Answer 8

substances for transport or export

Question 9

Cellular membranes are composed of a…

Answer 9

phospholipid bilayer

Question 10

Organelles common to animal and plant cells:

Answer 10

Nucleus
Endoplasmic reticulum
Golgi apparatus
Mitochondrion

Question 11

Organelles unique to animal cells:

Answer 11

Lysosome

Question 12

Organelles unique to plant cells:

Answer 12

central vacuole

chloroplast

Question 13

Plasma membranes…

Answer 13

control movement of substances

Question 14

Phospholipid bilayers are made of:

Answer 14

Hydrophilic (phosphate) heads

hydrophobic tails

Question 15

cholesterol…

Answer 15

stabilises membrane fluidity

Question 16

Three types of transport:

Answer 16

Passive transport
Active transport
Co-transport

Question 17

Fluid membranes

Answer 17

phospholipid tails are unsaturated (bent)

Question 18

Viscous membranes

Answer 18

phospholipid tails are saturated (straight)

Question 19

Examples of passive transport:

Answer 19

diffusion
facilitated diffusion
osmosis

Question 20

Hydrophobic molecules include:

Answer 20

steroid hormones/gasses

Question 21

Facilitated transport requires…

Answer 21

membrane proteins called channels/carriers

Question 22

Channel proteins for water to move are called

Answer 22

aquaporins

Question 23

Passive transport needs

Answer 23

no energy

Question 24

Active transport needs

Answer 24

energy (ATP)

Question 25

Active transport allows

Answer 25

movement against concentration gradient

Question 26

Co-transport uses

Answer 26

concentration gradient of a substance to power the movement of a second against its gradient

Question 27

Co-transport needs

Answer 27

energy (ATP)

Question 28

Roles of membrane proteins:

Answer 28

signal transduction,
cell recognition,
intercellular joining,
linking cytoskeleton and extracellular matrix

Question 29

signal transduction relays

Answer 29

messages from body/environment into cell

Question 30

cell recognition involves…

Answer 30

glycoproteins (proteins with added sugars)