BIO WGU OA C190 EXAM STUDY GUIDE
2026 FULL SOLVED QUESTIONS AND
ANSWERS
⩥ key functions of lipids. Answer: makes up cell membrane, energy
storage
⩥ 2 primary functions of the cell membrane. Answer: 1. define cell
boundary
2. regulation of molecules
⩥ main components of the cell membrane. Answer: - lipids
- proteins
- carbohydrates
⩥ what contributes to the fluidity of a membrane?. Answer: lipid types
& characteristics of fatty acid chains
⩥ amphipathic. Answer: having both hydrophilic & hydrophobic regions
⩥ which part of a phospholipid is hydrophilic?. Answer: head
,⩥ which part of a phospholipid is hydrophobic?. Answer: fatty acid tails
⩥ main function of a phospholipid. Answer: forms the cell membrane
⩥ lipid bilayer. Answer: 2 layers of lipids
⩥ which part of the phospholipid is tucked inside the membrane?.
Answer: nonpolar, hydrophobic tail
⩥ why is the polar part of the phospholipid facing outward?. Answer:
can form bonds
⩥ liposome. Answer: spherical bilayer structure
- forms in aqueous environment at neutral pH
⩥ why is pH important?. Answer: ensures polar head is in ionized form--
makes them hydrophilic
⩥ van der Waals forces. Answer: weak binding of temporarily polarized
molecules due to attraction of opposite charges
- helps w/ sticking of cholesterol/phospholipids in a cell membrane
⩥ saturated fats. Answer: - NO carbon=carbon double bonds
, - straight structure
- tight packing --> reduces mobility (fluidity)
⩥ unsaturated fats. Answer: - carbon=carbon double bonds
- kinked structure
- reduced tightness of packing --> enhances mobility (fluidity)
⩥ cholesterol. Answer: makes up 30% of cell membrane
⩥ which part of cholesterol is hydrophilic?. Answer: hydroxyl group on
steroid ring A
⩥ what role does cholesterol play in a cell membrane?. Answer: helps
with tight-packing
⩥ what is the orientation of cholesterol?. Answer: amphipathic
- hydrophobic, rigid planar group of rings & hydrophobic hydrocarbon
tail
(interacts w/ hydrophobic fatty acid tails of phospholipid)
- hydrophilic head group
(interact w/ hydrophilic head of phospholipid)
⩥ 2 types of membrane proteins. Answer: 1. integral
2026 FULL SOLVED QUESTIONS AND
ANSWERS
⩥ key functions of lipids. Answer: makes up cell membrane, energy
storage
⩥ 2 primary functions of the cell membrane. Answer: 1. define cell
boundary
2. regulation of molecules
⩥ main components of the cell membrane. Answer: - lipids
- proteins
- carbohydrates
⩥ what contributes to the fluidity of a membrane?. Answer: lipid types
& characteristics of fatty acid chains
⩥ amphipathic. Answer: having both hydrophilic & hydrophobic regions
⩥ which part of a phospholipid is hydrophilic?. Answer: head
,⩥ which part of a phospholipid is hydrophobic?. Answer: fatty acid tails
⩥ main function of a phospholipid. Answer: forms the cell membrane
⩥ lipid bilayer. Answer: 2 layers of lipids
⩥ which part of the phospholipid is tucked inside the membrane?.
Answer: nonpolar, hydrophobic tail
⩥ why is the polar part of the phospholipid facing outward?. Answer:
can form bonds
⩥ liposome. Answer: spherical bilayer structure
- forms in aqueous environment at neutral pH
⩥ why is pH important?. Answer: ensures polar head is in ionized form--
makes them hydrophilic
⩥ van der Waals forces. Answer: weak binding of temporarily polarized
molecules due to attraction of opposite charges
- helps w/ sticking of cholesterol/phospholipids in a cell membrane
⩥ saturated fats. Answer: - NO carbon=carbon double bonds
, - straight structure
- tight packing --> reduces mobility (fluidity)
⩥ unsaturated fats. Answer: - carbon=carbon double bonds
- kinked structure
- reduced tightness of packing --> enhances mobility (fluidity)
⩥ cholesterol. Answer: makes up 30% of cell membrane
⩥ which part of cholesterol is hydrophilic?. Answer: hydroxyl group on
steroid ring A
⩥ what role does cholesterol play in a cell membrane?. Answer: helps
with tight-packing
⩥ what is the orientation of cholesterol?. Answer: amphipathic
- hydrophobic, rigid planar group of rings & hydrophobic hydrocarbon
tail
(interacts w/ hydrophobic fatty acid tails of phospholipid)
- hydrophilic head group
(interact w/ hydrophilic head of phospholipid)
⩥ 2 types of membrane proteins. Answer: 1. integral
