Week2) lipids

Question 1

Lipids

Answer 1

• Loosely defined group of molecules with an important chemical Characteristic:
• They are inslouble in water
• high proportion of nonpolar C-H bonds causes the molecule to be hydrophobic
• Fats, oils, waxes, steroids, membrane components and

Question 2

Fats

Answer 2

• triglycerides
• composed of 1 glycerol and 3 fatty acids
• Fatty acids
• need not be identical
• chain length varies
• Saturated- no double bonds between carbon atoms
• higher melting point, animal origin
• Unsaturated-1 or more double

Question 3

Phospholipids composed of

Answer 3

• glycerol
• 2 fatty acids-nonpolar “tails”
• a phosphate group- polar “head”

Question 4

Phospholipid bilayer

Answer 4

more complicated structure where 2 layers form
- hydrophilic heads point outward (in contact with the aqueous enviroment)
- Hydrophobic tails point inward toward eachother

Question 5

phospholipids form

Answer 5

all biological membranes

Question 6

Micelles

Answer 6

• lipid molecules oriented with:
• polar (hydrophilic) head toward water
• nonpolar (hydrophobic) tails away

Question 7

Types of lipids-steroids

Answer 7

cholesterol (a steroid) is a precursor to steroid hormones (androgens, estrogens, etc)