What is the connection between DNA in chloroplasts and proteins ?

Chloroplasts are semi-autonomously inherited organelles! The DNA in chloroplasts can control the synthesis of small parts of proteins that they need; Most of the rest of the proteins are synthesized by nuclear DNA, which is then transported into chloroplasts!

The DNA in the chloroplast can also control and synthesize some of its own proteins, and the DNA in the nucleus can control the synthesis of all proteins in the body.

Chloroplasts don't have DNA, right, protein stores nutrients, personal opinion.

The DNA in the matrix of chloroplasts is present in a circular form within both types of organelles, similar to bacteria. It is also genetic, so these two types of cells are controlled by both the nucleus and their own genetic material. This DNA is distributed in the matrix and exists in a free form.

It does not bind to proteins, but it controls protein synthesis, which is a necessary connection.

DNA directs protein synthesis.

Ribosomes are found in chloroplasts and mitochondria, and they do not all provide synthetic proteins.

The proteins expressed by the DNA of chloroplasts and mitochondria are mainly mitochondria or chloroplast's own structural proteins, which are not secreted into the cytoplasm.

Chloroplast and mitochondrial DNA self-replication, their replication is generally regulated by the nucleus, and although they have their own circular DNA molecules, not all of them provide synthetic proteins.

Protein Synthesis:

The ribosome is like a small mobile factory, along the mRNA template, and the peptide chain is rapidly synthesized forward. The aminoacyl tRNA enters the ribosome at a very large rate, transferring the amino acid to the peptide chain and being expelled from the ribosome, and the elongation factor is constantly binding and dissociating from the ribosome. Together, ribosomes and additional factors provide the active region for each step of protein synthesis.

There are many differences between prokaryotes and eukaryotes in the protein synthesis process, and eukaryotes are more complex in this process, the following focuses on the process of prokaryotic protein synthesis and points out the differences between eukaryotes and them. Protein biosynthesis can be divided into five stages, the activation of amino acids, the initiation of polypeptide chain synthesis, the elongation of peptide chains, the termination and release of peptide chains, and the processing and modification after protein synthesis.

That's right. Ribosomes are organelles that can synthesize proteins, and chloroplasts can also synthesize some proteins.

Many scholars refer to the genetic information system of mitochondria and chloroplasts as the second genetic information system of eukaryotic cells, or extranuclear genes and their expression systems. This is because studies have found that in addition to DNA, mitochondria and chloroplasts also contain RNA (mRNA, tRNA, rRNA), ribosomes, amino acid-activating enzymes, etc. This indicates that both organelles have the function of transcription and translation independently.

In other words, both mitochondria and chloroplasts have their own systems for transcribing RNA and translating proteins. However, so far, it has been found that chloroplasts can synthesize only 13 proteins, mitochondria can synthesize only more than 60 proteins, and there are thousands of proteins involved in the composition of mitochondria and chloroplasts. This shows that there are not many proteins in mitochondria and chloroplasts that are synthesized by themselves, and the vast majority of them are encoded by nuclear genes and synthesized on cytoplasmic ribosomes.

That is, mitochondria and chloroplasts have a limited degree of autonomy, and they have a great dependence on the nuclear genetic system. Therefore, the growth and proliferation of mitochondria and chloroplasts are controlled by two sets of genetic information systems, the nuclear genome and their own genome, so they are both called semi-autonomous organelles.

Both have ribosomes that are capable of synthesizing proteins.

Chloroplast is an important organelle responsible for photosynthesis in plant cells, and it has its own genetic material DNA and protein synthesis mechanism, which can independently carry out protein synthesis. Because chloroplasts have a special double-layer membrane structure and endoplasmic reticulum system, it is able to bind synthesized proteins to its interior, preventing it from spilling into other cytoplasms.

Specifically, protein synthesis in chloroplasts is mainly controlled by chloroplast genes and nuclear genes, and different transcription and translation mechanisms are used to produce different types and structures of egg hole white matter, which mainly include enzymes required for photosynthesis, chlorophyll proteins, reaction center complexes, plasma membrane proteins, electron transport chain complexes, etc. During protein synthesis, chloroplasts guarantee proper folding, activation, and localization of these proteins through a post-translational modification and maturation process. Among them, the protection and localization of chloroplast proteins are mainly achieved through molecular chaperones, localization sequences and targeted signaling pathways, which orientally deliver mature proteins to the interior of chloroplasts.

At the same time, chloroplasts also have unique enzymes and protein complexes, which can specifically modify, reduce the nucleus and decompose proteins, synthesize and stabilize them, and further ensure the correct localization and functional realization of proteins. Overall, chloroplasts are able to bind the expressed protein to their interior through complex vibrator mechanisms, enzymatic reactions, and spatial structures.

Intracellular life bai

The direct energy source of the activity is ATP, whether it is DNA replication, ZHI or protein synthesis, or other DAO life activities.

ATP has two combinations within the organism.

Genus pathway 1, respiration. 2. Photosynthesis.

However, ATP for photosynthesis does not provide energy for cellular life activities. The ATP of the light reaction is all fixed by the dark reaction.

SO Answer: All energy is supplied by ATP from cellular respiration.

ATP Respiration The energy of photosynthesis is used in the dark reaction phase.

Chloroplasts are found in green plants, so they are produced through photosynthesis.

It is provided by ATP produced by cellular respiration.

The DNA in chloroplasts is inherently present. This is related to the origin of chloroplasts.

It is currently believed that chloroplasts arise from cyanobacteria that are symbiotic within primitive eukaryotic cells. This theory is called the "endosymbiosis theory of chloroplasts".

The theory holds that the direct ancestor of eukaryotic cells is a huge, nonaerobic, unicellular archayotic with phagocytosis capacity, which obtains the energy needed for their life activities by devouring sugars and breaking them down. A part of these archayotes, while devouring eubacteria, also devoured some primitive cyanobacteria, namely cyanobacteria. However, cyanobacteria are not digested by palakaryotic cells after entering the cells of archaeokaryotes, but become parasitic cells and provide nutrients for the host cell through photosynthesis, and the host cell provides the conditions for its survival.

This intracellular symbiotic relationship is beneficial to both parties, so that the two parties have established a progressively fixed relationship in evolution.

Because the environment in which eubacteria live in symbiosis is different from that when they live independently, many of the original structures and functions become unnecessary and gradually degenerate and disappear. As a result, the eubacteria that are symbiotic in cells have become more and more specialized, and eventually evolved to become chloroplasts, a kind of intracellular organ in the cells of these archayotes, through a similar endosymbiotic process, exercising photoautotrophic functions. To this day, chloroplasts still retain some of the basic characteristics and traces of their ancestors, such as chloroplasts have their own DNA, which provides evidence for this theory and is widely accepted by the scientific community.

What I want to correct is that cyanobacteria are prokaryotes, not eukaryotes.

Hello lz.

Whether a plant cell has chloroplasts is indeed the result of selective expression of genes In fact, chloroplasts, as well as mitochondria, the structure of their organelle membranes is very close to the appearance of a single-celled bacterium--- the outer membrane structure is very close to the surface structure of normal cell membranes, and the inner membrane structure is more like the cell membrane of bacteria, and the DNA in mitochondrial chloroplasts is covalently circular, and by the way, it has its own ribosomes, and some proteins do not need to run outside the organelle to synthesize ......

Further research, scientists have come to the following conclusions:

Chloroplasts can synthesize about 13 proteins, and mitochondria have a little more, about 60, but neither of them is enough to assemble itself. Therefore, the formation of this chloroplast (and mitochondria) must be regulated by nuclear genes! Therefore, it is indeed selectively expressed.

Not exactly. The chloroplast is composed of three parts: chloroplast envelope, thylakoid, and stroma, and chloroplasts contain 3 different membranes: the outer membrane, the inner membrane, the thylakoid membrane, and 3 cavities that are separated from each other

Intermembrane space, stromal, and thylakoid lumen.

a) Outer cover. The chloroplast is composed of a double membrane with a 10-20 nm intermembrane space. The outer membrane is highly permeable, and many nutrient molecules in the cytoplasm, such as nucleosides, inorganic phosphorus, sucrose, etc., can enter the membrane space from the remnants.

The inner membrane is very selective to the passing substances, CO2, O2, PI, H2O, phosphoglyceric acid, triose phosphoric acid, dicarboxylic acid and dicarboxylic acid amino acids can penetrate the inner membrane, ADP, ATP hexalose phosphate, glucose and fructose are slow to penetrate the inner membrane. Sucrose, C5 sugar bisphosphonate, C sugar phosphate, NaDP+ and pyrophosphate are impermeable to the inner membrane and require special transporters (translators) to pass through the inner membrane.

b) Thyloids.

It is a small flat sac enclosed by a single membrane, arranged parallel to the long axis of the chloroplast. The membrane contains photosynthetic pigments and electron transport chain components, also known as photocavity cracking and rolling films.

Many thylakoids are stacked on top of each other like discs and are called basal granules, and the thylakoids that make up the basal grains are called stalmotriate thylakoids, which form the grana lamella of the endometrial systemThe basal granule is about 10 100 thylakoids in diameter. There are about 40 60 basal grains in each chloroplast.

Tharynoids that do not stack between two or more bactriles are called stromal thylakoids, which form a stroma lamella of the endomembrane system

Since adjacent stromes are connected by reticulum tubular or flat stromal thylakoids, all thylakoids are essentially a closed system that is interconnected. The original concept of thylakoids as a single enclosed membranous sac has lost its original meaning, and it represents only the planar morphology of the chloroplast section.

The main components of the thylakoid membrane are proteins and lipids (60:40), and the fatty acids in lipids are mainly unsaturated fatty acids (about 87%), which have high fluidity. The conversion of light energy to chemical energy is carried out on the thylakoid, so the thylakoid membrane is also known as the photosynthetic membrane, and the intrinsic proteins of the thylakoid membrane mainly include cytochrome B6 F complex, plastid quinone (PQ), plastidin (PC), iron redox protein, flavin protein, photosystem, photosystem complex, etc.

iii) Substrate. It is the space between the intima and the thylakoids, and the main components include:

Chloroplast DNA, protein synthesis system: e.g., CTDNA, various RNA, ribosomes, etc.

Some granular components: such as starch grains, plastid globules, and plant ferritin, etc.

The reason why DNA in the nucleus is packaged into chromosomes is because the molecular weight is too large, if it is not packaged into chromosomes, the cell cannot accommodate it at all, while the molecular weight of DNA in mitochondria and chloroplasts is much smaller, and it is circular, on the other hand, the chromosomal DNA in the nucleus is protected by proteins, and the main purpose is to prevent mutations, because if the DNA in the nucleus is mutated, the impact is very large, and the number of mitochondria in the cell is very huge, Even though the DNA mutation rate in mitochondria is more than 10 times higher than that of nuclear DNA, the genetic impact on cells is not significant

【Answer】d

Answer analysis] test question analysis: from the meaning of the question, chloroplast DNA guides the synthesis of its own protein, according to the protein synthesis process, chloroplast DNA is genetic material, can be transcribed, and there are ribosomes in chloroplast; However, only a small part of the protein is guided by DNA in chloroplasts, and most of the proteins that determine the function of chloroplasts are regulated by the nucleus, which is the control center of the cell.

Test Center: This question examines the synthesis of proteins and the function of the nucleus.

Comments: For this type of question, students should master the synthesis of proteins and the function of the nucleus.