What does Lhcii protein do?
What does Lhcii protein do?
The role of LHCII is to absorb light and to transfer excitation energy to the reaction center where charge separation occurs.
Do chloroplasts synthesize proteins?
In chloroplasts, a few thousand proteins function in photosynthesis, expression of the chloroplast genome, and other processes. Most chloroplast proteins are synthesized in the cytoplasm, imported, and then targeted to a specific chloroplast compartment.
What are light harvesting proteins?
A light-harvesting complex consists of a number of chromophores which are complex subunit proteins that may be part of a larger super complex of a photosystem, the functional unit in photosynthesis.
How are proteins targeted to chloroplasts?
Proteins destined for the mitochondrial matrix or chloroplast stroma have organelle-specific N-terminal uptake-targeting sequences that direct their entry into the organelle. After protein import, the targeting sequence is removed by proteases within the matrix or stroma.
What is Lhcii and where is it localized?
Light-harvesting complex (LHC) proteins of plants and eukaryotic microalgae are located in the thylakoid membrane of the chloroplasts. Monomeric LHCII proteins are less abundant and are located in close proximity to the PSII core complex.
Where is Lhcii?
The light-harvesting complex II (LHCII)—the main antenna of PSII—accounts for about half of the chlorophyll molecules in nature and is the most abundant integral membrane protein in chloroplasts.
How photosynthesis is linked to protein synthesis?
Photosynthesis correlates to polysome abundance and phosphorylation of ribosomal proteins and translation initiation factors. Protein synthesis activity and translation correlate positively with photosynthesis.
What is synthesized chloroplast?
Characteristics and products of protein synthesis in vitro in etioplasts and developing chloroplasts from pea leaves.
What is the main role of the light harvesting complexes in the photosystems?
The light-harvesting complex (or antenna complex; LH or LHC) is an array of protein and chlorophyll molecules embedded in the thylakoid membrane of plants and cyanobacteria, which transfer light energy to one chlorophyll a molecule at the reaction center of a photosystem.
What are the main constituents of light-harvesting pigment?
Three major types of pigments occur in photosynthetic algae: chlorophyll, carotenoids, and phycobilins (Rabinowitch & Govindjee, 1969).
What is the chloroplast membrane made of?
Chloroplast membranes consist of about 45% protein and 55% lipid. Some 80% of the lipids are the highly surfactant glycolipids. In this paper the subunits are visualized as assymetric lipoproteins, probably having a protein core surrounded by com- ponents determined by the nature and environment of the membrane.
Where are proteins in the chloroplast synthesized quizlet?
The chloroplast proteins that are encoded by the nuclear DNA are synthesized in the cytosol, and the sorting signals on the protein direct them to the chloroplast. The chloroplast proteins encoded by the chloroplast DNA are synthesized on ribosomes inside the chloroplast.
Is there a new intermediate of LHCII at 660 nm?
The carotenoid contributions appear to lose intensity at 480 and 472 nm and gain intensity at 457 nm. In the Chl Q y region, a new band is present at 660 nm in LHCII isolated in α-DM, while the intensity of the transitions at 676 and 672 nm is reduced.
Which is a trimer of the LHCII antenna complex?
LHCII, the major antenna complex in higher plants, occurs as a trimer of nearly identical monomers. Each monomer binds 14 chlorophyll molecules (8 Chl a and 6 Chl b ), three tightly-bound carotenoids (two luteins and one 9- cis neoxanthin), and one weakly-bound violaxanthin carotenoid ( 16 ).
Where is the protein synthesis site in Escherichia coli?
Protein Synthesis Initiation. Shine-Dalgarno (SD) sequence – In Escherichia coli is observed sequence with high percentage of purine nucleotide bases, known as the Shine-Dalgarno sequence. This region is located close to 5’ end of the mRNA molecule, 6-10 bases upstream of the initiating codon.
How is translation elongation related to protein synthesis?
Translation Elongation. During the elongation step the polypeptide chain adds amino acids to the carboxyl end the chain protein grows as the ribosome moves from the 5′ -end to the 3′-end of the mRNA. In prokaryotes, the delivery of the aminoacyl-tRNA to ribosomal A site is facilitated by elongation factors EF-Tu-GTP and EF-Ts,…
