Biochemistry
9th Edition
ISBN: 9781305961135
Author: Mary K. Campbell, Shawn O. Farrell, Owen M. McDougal
Publisher: Cengage Learning
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Textbook Question
Chapter 20, Problem 14RE
REFLECT AND APPLY Comment on the fact that the reduction of pyruvate to lactate, catalyzed by lactate dehydrogenase, is strongly exergonic (recall this from Chapter 15), even though the standard free-energy change for the half reaction
is positive
Expert Solution & Answer
Trending nowThis is a popular solution!
Students have asked these similar questions
Obtain the sequence for the 5-HT receptor HTR1A and generate a hydropathy plot usingthe ExPASY tool ProtScale, the appropriate window, and the Kyte-Doolittle weightingalgorithm. How many transmembrane domains are present in this receptor?
From the reaction data below, determine whether the reaction is first order or second order and calculate the rate constant.
Time (s)
0
Reactant (mM)
5.4
1
4.6
2
3.9
3
3.2
4
2.7
5
2.3
Only a plot of In[reactant] versus t gives a straight line, so the reaction is
first order
. The negative of the slope, k, is
0.171
Hair grows at a rate of about 20 cm/yr. All this growth is concentrated at the base of the hair fiber, where a-keratin filaments are
synthesized inside living epidermal cells and assembled into ropelike structures.
Two-chan
14
Protofilament
20-30 A
Two-chain
Intermediate
flament
-Protob
Protofilament
Cross section of a hair
The fundamental structural element of a keratin is the a helix, which has 3.6 amino acid residues per turn and a rise of 5.4 A
perlum.
54A
(36)
Amino terminus
Carbon
Hydrogen
Oxygen
Nitrogen
group
Carboxyl terminus
Assuming that the biosynthesis of a helical keratin chains is the rate-limiting factor in the growth of hair, calculate the rate at
which peptide bonds of a-keratin chains must be synthesized (peptide bonds per second) to account for the observed yearly
growth of hair.
0422
rate of peptide bond formation:
Income
bonds/s
Chapter 20 Solutions
Biochemistry
Ch. 20 - RECALL Briefly summarize the steps in the electron...Ch. 20 - RECALL Are electron transport and oxidative...Ch. 20 - Prob. 3RECh. 20 - REFLECT AND APPLY Show how the reactions of the...Ch. 20 - REFLECT AND APPLY How does mitochondrial structure...Ch. 20 - Prob. 6RECh. 20 - Prob. 7RECh. 20 - MATHEMATICAL Using the information in Table 20.2,...Ch. 20 - Prob. 9RECh. 20 - Prob. 10RE
Ch. 20 - MATHEMATICAL Calculate E for the following...Ch. 20 - Prob. 12RECh. 20 - MATHEMATICAL Which is more favorable...Ch. 20 - REFLECT AND APPLY Comment on the fact that the...Ch. 20 - RECALL What do cytochromes have in common with...Ch. 20 - RECALL How do the cytochromes differ from...Ch. 20 - RECALL Which of the following does not play a role...Ch. 20 - Prob. 18RECh. 20 - Prob. 19RECh. 20 - REFLECT AND APPLY Two biochemistry students are...Ch. 20 - REFLECT AND APPLY Cytochrome oxidase and...Ch. 20 - Prob. 22RECh. 20 - REFLECT AND APPLY Reflect on the evolutionary...Ch. 20 - REFLECT AND APPLY Experimental evidence strongly...Ch. 20 - Prob. 25RECh. 20 - REFLECT AND APPLY What is the advantage of having...Ch. 20 - REFLECT AND APPLY Why do the electron-transfer...Ch. 20 - Prob. 28RECh. 20 - Prob. 29RECh. 20 - Prob. 30RECh. 20 - RECALL Describe the role of the F1 portion of ATP...Ch. 20 - Prob. 32RECh. 20 - Prob. 33RECh. 20 - Prob. 34RECh. 20 - REFLECT AND APPLY What is the approximate P/O...Ch. 20 - REFLECT AND APPLY Why is it difficult to determine...Ch. 20 - REFLECT AND APPLY What are some of the...Ch. 20 - RECALL Briefly summarize the main arguments of the...Ch. 20 - Prob. 39RECh. 20 - Prob. 40RECh. 20 - Prob. 41RECh. 20 - Prob. 42RECh. 20 - REFLECT AND APPLY Criticize the following...Ch. 20 - Prob. 44RECh. 20 - Prob. 45RECh. 20 - Prob. 46RECh. 20 - RECALL How does the yield of ATP from complete...Ch. 20 - REFLECT AND APPLY The malate-aspartate shuttle...Ch. 20 - MATHEMATICAL What yield of ATP can be expected...Ch. 20 - MATHEMATICAL The free-energy change (G) for the...
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, biochemistry and related others by exploring similar questions and additional content below.Similar questions
- Specific rotation is a measure of a solution's capacity to rotate circularly polarized light. The unfolding of the a helix of a polypeptide to a random conformation is accompanied by a large decrease in specific rotation. Polyglutamate, a polypeptide made up of only 1-Glu residues, has the a helix conformation at pH 3. When researchers raise the pH to 7, there is a large decrease in the specific rotation of the solution. Similarly, polylysine (1.-Lys residues) is an a helix at pH 10, but when researchers lower the pH to 7 the specific rotation also decreases, as shown in the graph. a Helix Specific rotation Poly(Glu) a Helix Random conformation Poly(Lys) Random conformation T + ° 2 4 6 В 10 12 14 PH Complete the statements about the molecular mechanism for these changes in specific rotation. Increasing the pH of a polyglutamate solution from 6 to 7 causes the carboxyl group of each glutamate residue Comed Artwer lose a proton. The negatively charged groups in each glutamate residue…arrow_forwardFrom the reaction data below, determine whether the reaction is first order or second order and calculate the rate constant. Time (s) 0 Reactant (mM) 6.2 1 3.1 2 2.1 3 1.6 4 1.3 5 1.1 Only a plot of 1/[reactant] versus t gives a straight line, so the reaction is 0.150 mM-1 s-1 . S second order . The slope, k, isarrow_forwardFrom the reaction data below, determine whether the reaction is first order or second order and calculate the rate constant. Time (s) 0 Reactant (mM) 5.4 1 4.6 2 3.9 3 3.2 4 2.7 5 2.3 Only a plot of In[reactant] versus t gives a straight line, so the reaction is s-1. . The negative of the slope, k, isarrow_forward
- A protein has a molecular mass of 400 kDa when measured by size-exclusion chromatography. When subjected to gel electrophoresis in the presence of sodium dodecyl sulfate (SDS), the protein gives three bands with molecular masses of 180, 160, and 60 kDa. When electrophoresis is carried out in the presence of SDS and dithiothreitol (DTT), three bands again form, this time with molecular masses of 160, 90, and 60 kDa. How many subunits does the protein have, and what is the molecular mass of each? four subunits: 180, 160, 90, and 60 kDa three subunits: 180, 160, and 60 kDa three subunits: 160, 90, and 60 kDa four subunits: 160, 90, 90, and 60 kDa Correct Answerarrow_forwardCalculate KM and Vmax from the following data: KM= i Vmax [S] (μM) vo (mM.s-¹) 0.1 0.34 0.2 0.53 0.4 0.74 0.8 0.91 1.6 1.04 μM mM s-1arrow_forwardPropose a detailed chemical mechanism for the enzyme catalyzed reaction below and briefly note similarities, if any, to enzymes that we've studied. CO2 + CO2 2 CO2 HO CH3arrow_forward
- 11. Which of the compounds below is the major product of the following reaction sequence? NOTE: PCC is pyridinium chlorochromate 1. BH 3 PCC 2. H2O2, NaOH NH HN ΗΝ, A B C CH3NH2, NaBH3CN D E NHarrow_forward10. Which of the compounds below is the major organic product obtained from the following reaction sequence? Ph Ph Ph A B OH 1. EtMgBr H2CrO4 Zn(Hg), aq. HCI PhCHO ? 2. H₂O, H+ Ph. C D Ph "ར HO OH Earrow_forward7. What is the major organic product obtained from the following reaction sequence? Ph A OH 99 Ph OH D Br HOCH2CH2OH H2SO4 1. Mg, Et₂O 2. PhCH2CHO HCI, H₂O Br OH Ph Ph OH B C Br OH Ph Earrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
BiochemistryBiochemistryISBN:9781305961135Author:Mary K. Campbell, Shawn O. Farrell, Owen M. McDougalPublisher:Cengage Learning
Biochemistry
Biochemistry
ISBN:9781305961135
Author:Mary K. Campbell, Shawn O. Farrell, Owen M. McDougal
Publisher:Cengage Learning
Biomolecules - Protein - Amino acids; Author: Tutorials Point (India) Ltd.;https://www.youtube.com/watch?v=ySNVPDHJ0ek;License: Standard YouTube License, CC-BY