Three factors are important in maintaining low O2 concentrations in nodules. 

First, entry of O2 into the nodule is controlled by a variable‐permeability barrier in the nodule parenchyma

TLS Online TPP Program

#Id: 8106

#Section 2: General Biology

Galactolipids are localized in the thylakoid membranes (internal membranes) of chloroplasts; they make up 70% to 80% of the total membrane lipids of a vascular plant, and are therefore probably the most abundant membrane lipids in the biosphere. 

TLS Online TPP Program

#Id: 8043

#Section 2: General Biology

RS Configuration 

Atoms of higher atomic number rank above those of lower atomic number (e.g., —OH ranks above —CH3). If the first substituent atoms are identical, the priority is established by the next atom outward from the chiral center (e.g., —CH2OH takes precedence over —CH3).

TLS Online TPP Program

#Id: 8406

#Section 3: Genetics, Cellular and Molecular Biology

Vertebrate skeletal muscle contraction, also depends on set of specialized accessory proteins that are closely associated with the actin thin filaments:

a) Tropomyosin

b) Troponin

TLS Online TPP Program

#Id: 9284

#Section 2: General Biology

O2‐binding plant protein Lb plays an active role in regulating and delivering O2 in the infected cells

Bacterial respiration is the major O2 sink

TLS Online TPP Program

#Id: 8963

#Section 3: Genetics, Cellular and Molecular Biology

If the duplicate is redundant and does not provide a fitness benefit, it will be lost by deletion or the accumulation of loss of-function mutations.

A second fate is that a duplicate can simply retain its original function.