Biochemistry: The Molecular Basis of Life
6th Edition
ISBN: 9780190209896
Author: Trudy McKee, James R. McKee
Publisher: Oxford University Press
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Chapter 12, Problem 28RQ
Summary Introduction
To review:
The relation between lipid molecules like steroid molecules, such as estrogen and β-carotene.
Introduction:
Lipids are known to play a vital role in living organisms largely due to the presence of hydrophobic structures. They serve as highly efficient and compact the energy storage molecules like triacylglycerol, they are vital elements of biological membranes and have diverse membrane-linked molecules which have signaling or protective functions.
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Students have asked these similar questions
Given the values for the changes in enthalpy (AH) and entropy (AS), which processes can take place at 298 K without
violating the Second Law of Thermodynamics?
(a) AH =
(b) AH = -84 kJ mol¹ (−20 kcal mol¹), AS = -125 J mol-¹ K-¹ (-30 cal mol-¹ K-¹)
(c) AH = +84 kJ mol¹ (+20 kcal mol¯¹), AS = +125 J mol¯¹ K−¹ (+30 cal mol-¹ K-¹)
(d) AH = +84 kJ mol-1 (+20 kcal mol-¹), AS = -125 J mol¯¹ K-¹ (-30 cal mol-¹ K-¹)
-84 kJ mol¹ (-20 kcal mol¹), AS = +125 J mol¯¹ K-¹ (+30 cal mol-¹ K-¹)
What chemical interactions are primarily responsible for the fact that oil and water do not mix easily?
ionic interactions
covalent bonds
hydrogen bonding
Ohydrophobic effect
The carbon-nitrogen peptide bond is rigid, but rotation can take place
about the bond between the nitrogen and α-carbon atoms and the bond
between the α-carbon and the carbonyl carbon atom. These bond angles
define the conformation of the peptide chain.
Consider the Ramachandran plot shown to answer both questions.
(degrees)
180
120
60
60
0
Which observation most likely describes part of an observed a helix?
p=-59 degrees; = +150 degrees; many Ser residues
cp-140 degrees; w = +130 degrees; many Val residues
op-57 degrees; w = -47 degrees; many Pro residues
op-60 degrees; y = -47 degrees; many Ala residues
p = +60 degrees; y = +40 degrees; many Gly residues
-60
-120
-180
-180
0
➜ (degrees)
180
Chapter 12 Solutions
Biochemistry: The Molecular Basis of Life
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