4.5

a negatively charged and thus hydrophilic phosphate head two non polar hydrophobic fatty acides

The top is the hydrophilic head

The P is the phosphate group

the bottle is the hydrophobic tails

outward

mingling together and shielded from water

The boundary between the living cells and it's surroundings, controls the traffic

phosolipids

a negatively charged and thus hydrophilic phophate group (head) and two non polar, hydrophobic fatty acid tails

proteins

• non polar molecules,
• such as 0₂ and CO₂

form channels