Membranes and Transport

Question 1

Diffusion

Answer 1

the movement of molecules through a semipermeable barrier from an area of higher concentration to an area of lower concentration

Question 2

Osmosis

Answer 2

movement of water molecules from a solution with a high concentration of water molecules to a solution with a lower concentration of water molecules (basically diffusion but with water)

Question 3

Facilitated Diffusion

Answer 3

• channel proteins helping
• a type of diffusion that uses a transport or carrier protein to move large molecules across the cell membrane

Question 4

Hypotonic Solution

Answer 4

• has less solutes in the cell
• more water enters the cell, which causes it to expand, even burst

Question 5

Isotonic Solution

Answer 5

• has the same concentration of solutes as the cell
• equal amounts of water enter and exit the cell, so it stays the same size

Question 6

Hypertonic Solution

Answer 6

• has more solutes in the cell
• more water exits the cell, causing it to shrivel up and even die

Question 7

phospholipid bilayer

Answer 7

• The phospholipids in the cell membrane are arranged in two layers, called a phospholipid bilayer.
• Each phospholipid has a hydrophilic head and a hydrophobic tail
• selectively permeable
• pump out toxins/waste materials

Question 8

Types of membrane proteins

Answer 8

• junctions
• enzymes
• transport
• recognition

Question 9

junctions

Answer 9

Serve to connect and join two cells together

Question 10

Enzymes

Answer 10

Fixing to membranes localises metabolic pathways.

Question 11

Transport

Answer 11

Responsible for facilitated diffusion and active transport

Question 12

Recognition

Answer 12

May function as markers for cellular identification.

Question 13

The 7 membrane proteins

Answer 13

• Receptor Protein
• Adhesion Protein
• Anchor Protein
• Enzyme
• Glyco Protein
• Channel Protein
• Carrier Protein

Question 14

6 Components of the Cell Membrane

Answer 14

lipids (phospholipids and cholesterol), proteins, and carbohydrates attached to some of the lipids and some of the proteins. A phospholipid is a molecule consisting of glycerol, two fatty acids, and a phosphate-linked head group.

Question 15

Cell Size v. Diffusion

Answer 15

SMALLER CELLS ARE BETTER

Question 16

smaller cells

Answer 16

• better the volume to surface area ratio
• the larger the ratio of volume and surface area, the faster material exchange done with the atmosphere by the process of diffusion
• more surface area as opposed to volume
• With smaller cells, more surface area is available for oxygen and nutrients to diffuse in and carbon dioxide to diffuse out of the cell.

Question 17

larger cells

Answer 17

• worse
• smaller volume to surface area ratio
• more/larger holes in cell membrane
• harder it is for diffusion to occur
• the material can’t get to where it needs to go fast enough because there is more volume than there is surface area