BIOS 255 EXAM 2 TEST BANK QUESTIONS AND ACCURATE ANSWERS PRACTICE STUDY MATERIAL

BIOS 255 EXAM 2 TEST BANK QUESTIONS
AND ACCURATE ANSWERS PRACTICE
STUDY MATERIAL

●● 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