BIOLOGY I EXAM #2| TOP SCORES MADE SIMPLE |
TRUSTED TEST SOLUTIONS!
QUALITY CONTENT YOU CAN RELY ON!
cell theory Answer: the cell is the fundamental unit of life in all organisms & cells come
only from preexisting cells
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
1
APPHIA - Crafted with Care and Precision for Academic Excellence.
, - 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
2. peripheral
integral membrane proteins Answer: permanently associated w/ membrane
- unable to be separated
- hydrophilic AND hydrophobic regions
peripheral membrane proteins Answer: temporarily associated w/ membrane
- internal or external
- weak noncovalent interactions w/ polar heads or integral proteins
- transmits info from external signals
fluid mosaic model Answer: proposes that lipid bilayer --> fluid structure
- allows molec to move laterally within membrane
- mosaic of lipids/proteins
FRAP Answer: Fluorescent Recovery After Photobleaching
how does FRAP demonstrate the dynamic property of the plasma membrane? Answer:
plasma membrane...
- regulates movement of molec into/out of the cell
2
APPHIA - Crafted with Care and Precision for Academic Excellence.
TRUSTED TEST SOLUTIONS!
QUALITY CONTENT YOU CAN RELY ON!
cell theory Answer: the cell is the fundamental unit of life in all organisms & cells come
only from preexisting cells
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
1
APPHIA - Crafted with Care and Precision for Academic Excellence.
, - 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
2. peripheral
integral membrane proteins Answer: permanently associated w/ membrane
- unable to be separated
- hydrophilic AND hydrophobic regions
peripheral membrane proteins Answer: temporarily associated w/ membrane
- internal or external
- weak noncovalent interactions w/ polar heads or integral proteins
- transmits info from external signals
fluid mosaic model Answer: proposes that lipid bilayer --> fluid structure
- allows molec to move laterally within membrane
- mosaic of lipids/proteins
FRAP Answer: Fluorescent Recovery After Photobleaching
how does FRAP demonstrate the dynamic property of the plasma membrane? Answer:
plasma membrane...
- regulates movement of molec into/out of the cell
2
APPHIA - Crafted with Care and Precision for Academic Excellence.
