Role of Polyphenolic Molecular Size in Reduction of Assimilation Efficiency in Xiphister Mucosus

Ecology ◽  
1993 ◽  
Vol 74 (3) ◽  
pp. 891-903 ◽  
Author(s):  
Anne A. Boettcher ◽  
Nancy M. Targett
Keyword(s):  
Assimilation Efficiency ◽  
Molecular Size ◽  
Xiphister Mucosus

scholarly journals Insights into the role of protein molecule size and structure on interfacial properties using designed sequences

2013 ◽  
Vol 10 (80) ◽  
pp. 20120987 ◽  
Author(s):  
Mirjana Dimitrijev Dwyer ◽  
Lizhong He ◽  
Michael James ◽  
Andrew Nelson ◽  
Anton P. J. Middelberg
Keyword(s):  
Stress Response ◽  
Molecular Size ◽  
Interfacial Properties ◽  
Protein Molecule ◽  
Mixed System ◽  
Free Energy Of Adsorption ◽  
Air Water Interface ◽  
A Chain ◽  
Size And Structure

Mixtures of a large, structured protein with a smaller, unstructured component are inherently complex and hard to characterize at interfaces, leading to difficulties in understanding their interfacial behaviours and, therefore, formulation optimization. Here, we investigated interfacial properties of such a mixed system. Simplicity was achieved using designed sequences in which chemical differences had been eliminated to isolate the effect of molecular size and structure, namely a short unstructured peptide (DAMP1) and its longer structured protein concatamer (DAMP4). Interfacial tension measurements suggested that the size and bulk structuring of the larger molecule led to much slower adsorption kinetics. Neutron reflectometry at equilibrium revealed that both molecules adsorbed as a monolayer to the air–water interface (indicating unfolding of DAMP4 to give a chain of four connected DAMP1 molecules), with a concentration ratio equal to that in the bulk. This suggests the overall free energy of adsorption is equal despite differences in size and bulk structure. At small interfacial extensional strains, only molecule packing influenced the stress response. At larger strains, the effect of size became apparent, with DAMP4 registering a higher stress response and interfacial elasticity. When both components were present at the interface, most stress-dissipating movement was achieved by DAMP1. This work thus provides insights into the role of proteins' molecular size and structure on their interfacial properties, and the designed sequences introduced here can serve as effective tools for interfacial studies of proteins and polymers.

Molecular Sieving of Hydrophilic Molecules by the Rectal Intima of the Desert Locust (Schistocerca Gregaria)

1968 ◽  
Vol 48 (3) ◽  
pp. 521-532
Author(s):  
J. E. PHILLIPS ◽  
A. A. DOCKRILL
Keyword(s):  
Molecular Sieve ◽  
Schistocerca Gregaria ◽  
Molecular Size ◽  
Desert Locust ◽  
Rate Of Penetration ◽  
Molecular Sieving ◽  
Uniform Population

1. The permeability of perfused intimal sacs to fourteen non-ionic, hydrophilic molecules of graded molecular size was estimated by radioisotope flux. 2. The rectal cuticle acts as a molecular sieve severely restricting the rate of penetration of molecules with increasing hydrated size. 3. The penetration of test molecules was as predicted by the Renkin equation for a uniform population of water-filled pores having radii of 6.5 Å. 4. The properties of cuticles from the rectum and the integument are compared and the role of the rectal intima in the excretory process in the desert locust is discussed.

scholarly journals Transport of N-Nitrosamines through a Reverse Osmosis Membrane: Role of Molecular Size and Nitrogen Atoms

2018 ◽  
Vol 6 (1) ◽  
pp. 44-48 ◽  
Author(s):  
Takahiro Fujioka ◽  
Hitoshi Kodamatani ◽  
Long D. Nghiem ◽  
Takuji Shintani
Keyword(s):  
Reverse Osmosis ◽  
Molecular Size ◽  
Reverse Osmosis Membrane

scholarly journals Red knots (Calidris canutus islandica) manage body mass with dieting and activity

2020 ◽  
Vol 223 (21) ◽  
pp. jeb231993
Author(s):  
Kimberley J. Mathot ◽  
Eva M. A. Kok ◽  
Piet van den Hout ◽  
Anne Dekinga ◽  
Theunis Piersma
Keyword(s):  
Food Intake ◽  
Metabolic Rate ◽  
Body Mass ◽  
Assimilation Efficiency ◽  
Adaptive Significance ◽  
Fine Scale ◽  
Calidris Canutus ◽  
Predation Danger ◽  
Mitochondrial Efficiency

ABSTRACTMass regulation in birds is well documented. For example, birds can increase body mass in response to lower availability and/or predictability of food and decrease body mass in response to increased predation danger. Birds also demonstrate an ability to maintain body mass across a range of food qualities. Although the adaptive significance of mass regulation has received a great deal of theoretical and empirical attention, the mechanisms by which birds achieve this have not. Several non-exclusive mechanisms could facilitate mass regulation in birds. Birds could regulate body mass by adjusting food intake (dieting), activity, baseline energetic requirements (basal metabolic rate), mitochondrial efficiency or assimilation efficiency. Here, we present the results of two experiments in captive red knots (Calidris canutus islandica) that assess three of these proposed mechanisms: dieting, activity and up- and down-regulation of metabolic rate. In the first experiment, knots were exposed to cues of predation risk that led them to exhibit presumably adaptive mass loss. In the second experiment, knots maintained constant body mass despite being fed alternating high- and low-quality diets. In both experiments, regulation of body mass was achieved through a combination of changes in food intake and activity. Both experiments also provide some evidence for a role of metabolic adjustments. Taken together, these two experiments demonstrate that fine-scale management of body mass in knots is achieved through multiple mechanisms acting simultaneously.

The role of molecular size in ligand efficiency

2007 ◽  
Vol 17 (15) ◽  
pp. 4258-4261 ◽  
Author(s):  
Charles H. Reynolds ◽  
Scott D. Bembenek ◽  
Brett A. Tounge
Keyword(s):  
Molecular Size ◽  
Ligand Efficiency

The role of molecular size in antioxidant activity of peptide fractions from Pacific hake (Merluccius productus) hydrolysates

2012 ◽  
Vol 134 (3) ◽  
pp. 1297-1306 ◽  
Author(s):  
Imelda W.Y. Cheung ◽  
Lennie K.Y. Cheung ◽  
Nina Y. Tan ◽  
Eunice C.Y. Li-Chan
Keyword(s):  
Antioxidant Activity ◽  
Molecular Size ◽  
Merluccius Productus ◽  
Peptide Fractions

Role of NOM molecular size on iodo-trihalomethane formation during chlorination and chloramination

2016 ◽  
Vol 102 ◽  
pp. 533-541 ◽  
Author(s):  
Jie Zhang ◽  
Dan-Dan Chen ◽  
Lei Li ◽  
Wen-Wei Li ◽  
Yang Mu ◽  
...  
Keyword(s):  
Molecular Size

Water-in-Oil Emulsions:  Role of the Solvent Molecular Size on Droplet Interactions

Langmuir ◽  
1997 ◽  
Vol 13 (26) ◽  
pp. 7008-7011 ◽  
Author(s):  
F. Leal-Calderon ◽  
O. Mondain-Monval ◽  
K. Pays ◽  
N. Royer ◽  
J. Bibette
Keyword(s):  
Molecular Size ◽  
Oil Emulsions
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