Cell Ultrastructure and Plasma Membranes

Question 1

Explain how the term fluid mosaic model describes the structure of the plasma membrane? (3 marks)

Answer 1

1 mark - It likens the membrane to a mosaic of different components

1 mark - The components of the plasma membrane include phospholipids, cholesterol, proteins, and carbohydrates

1 mark - States how these components can move around to an extent

Question 2

How does the fluid mosaic model allow for membrane transport? (3 marks)

Answer 2

1 mark - Helps the cell membrane maintain its role

1 mark - Its role as a barrier

1 mark - A barrier between the inside and outside of the cell environments

Question 3

Explain what is diffusion (simple). (5 marks)

Answer 3

1 mark - A type of passive transport

1 mark - Transports small and uncharged molecules

1 mark - Transports through the semi-permeable membrane

1 mark - Transports down a concentration gradient

1 mark - Does not require energy

Question 4

Explain what’s facilitated diffusion. (6 marks)

Answer 4

1 mark - A type of passive transport

1 mark - Utilizes membrane proteins

1 mark - Carries large and charged molecules

1 mark - Transports down a concentration gradient

1 mark - Transports through a semi-permeable membrane

1 mark - Does not require energy

Question 5

Explain what’s Osmosis (6 marks)

Answer 5

1 mark - A type of passive transport

1 mark - Travels down a concentration gradient

1 mark - Does not require energy

1 mark - Transport of water

1 mark - May use membrane proteins such as aquaporins

1 mark - Travels through a semi-permeable membrane

Question 6

Two words for hydrophilic (1 mark)

Answer 6

Water loving

Question 7

Two words for hydrophobic (1 mark)

Answer 7

Water fearing

Question 8

Hydrophobic/Hydrophilic: Can mix with water (1 mark)

Answer 8

Hydrophilic

Question 9

Hydrophobic/Hydrophilic: Cannot mix with water (1 mark)

Answer 9

Hydrophobic

Question 10

What is the function of the nucleus? (4 marks)

Answer 10

1 mark: The control center of the cell

1 mark: Contains DNA

1 mark: Contains chromosomes

1 mark: Dictates how the cell is run

Question 11

What is the function of the mitochondria? (3 marks)

Answer 11

1 mark: The “power house” of the cell.

1 mark: Site of cellular respiration

1 mark: Generates ATP

Question 12

What is the function of the ribosome? (1 mark)

Answer 12

1 mark: Protein synthesis

Question 13

What is the function of the Golgi Apparatus? (2 marks)

Answer 13

1 mark: The “packaging center”

1 mark: Proteins are sorted for transport

Question 14

What is the function of the cell wall? (1 mark)

Answer 14

1 mark: Provides structure in its appropriate cell types

Question 15

What is the function of the rough ER? (1 mark)

Answer 15

1 mark: Quality control for some proteins

Question 16

What is the function of the smooth ER? (1 mark)

Answer 16

1 mark: Synthesis of lipids

Question 17

What is the function of the lysosome? (2 marks)

Answer 17

1 mark: Digestive system

1 mark: The rubbish cleaners of the cell

Question 18

What is the function of the cytoskeleton? (1 mark)

Answer 18

1 mark: Maintains cell shape

Question 19

Explain protein mediated transport. (5 marks)

Answer 19

1 mark: A type of active transport

1 mark: Uses membrane proteins

1 mark: Moves against a concentration gradient

1 mark: Crosses a semi-permeable membrane

1 mark: Uses energy

Question 20

Explain endocytosis. (7 marks)

Answer 20

1 mark: A type of active transport

1 mark: Uses vesicles

1 mark: Moves against a concentration gradient

1 mark: Requires energy

1 mark: Moves through a semipermeable membrane

1 mark: Involves cell entering the cell

1 mark: A type of bulk transport

Question 21

Explain exocytosis? (7 marks)

Answer 21

1 mark: A type of active transport

1 mark: Uses vesicles

1 mark: Moves against a concentration gradient

1 mark: Requires energy

1 mark: Moves through a semi-permeable membrane

1 mark: Involves cells exiting the cell

1 mark: A type of bulk transport

Question 22

What is cell compartmentalization? (1 mark)

Answer 22

1 mark: The process of forming cellular departments

Question 23

What benefits does cell compartmentalization provide eukaryotic cells? (1 mark)

Answer 23

1 mark: It increases the efficiency of processes

Question 24

Outline three differences between eukaryotic and prokaryotic cells (3 marks)

Answer 24

1 mark - Prokaryotic cells do not contain membrane bound organelles whilst eukaryotic cells do

1 mark - Prokaryotic cells are generally smaller in size than eukaryotic cells

1 mark - Eukaryotic cells have a more complex nature than prokaryotic cells

Question 25

What are the two types of endocytosis (2 marks)

Answer 25

1 mark - Phagocytosis
1 mark - Pinocytosis

Question 26

What molecules do phagocytosis take into the cell (1 mark)

Answer 26

1 mark - Solids

Question 27

What molecules do pinocytosis take into the cell (1 mark)

Answer 27

1 mark - Liquids

Question 28

Why are vesicles able to fuse with the plasma membrane? (1 mark)

Answer 28

1 mark - As vesicles are made of phospholipids