MindMap Gallery The replication mechanism of deoxyribonucleic acid (DNA)
The replication mechanism of deoxyribonucleic acid (DNA) involves the initiation phase, where replication origins are recognized and unwound by helicases; the elongation phase, where DNA polymerases catalyze the synthesis of new strands; and termination, where replication forks meet and termination signals are issued. The process includes proofreading and error correction mechanisms to ensure accuracy. Additionally, topological considerations, such as the maintenance of supercoiled structures, are crucial for preserving the stability of DNA structure during replication.
Edited at 2025-01-18 11:26:51In the introduction section, elastin is a protein that plays a crucial role in the body, endowing tissues with elasticity and toughness. Its properties include high elasticity and good ductility. Elastin has a wide range of sources and is commonly found in animal connective tissues such as skin and blood vessels. When using elastin in products, the amount and method of addition should be determined based on the characteristics of the product. It has many uses and can be added to skincare products to enhance skin elasticity and reduce wrinkles; Improving food texture and enhancing taste in the food industry; In the medical field, it can be used to make elastic scaffolds such as artificial blood vessels, providing support for tissue repair. Reasonable use can play its unique value.
This document aims to guide the proper use of proteins. Proteins are the fundamental substances that make up life and are essential for maintaining normal physiological functions in the body, with a wide variety of types. When using protein, daily diet is an important source, such as meat, eggs, etc., which are rich in high-quality protein. Measuring protein intake can be done using professional tools or methods to ensure that the intake meets the body's needs. When mixing protein powder, it should be prepared according to the recommended ratio, and the water temperature should not be too high to avoid damaging the protein activity. Different groups of people have different protein requirements, such as athletes and fitness enthusiasts who can increase their intake appropriately to meet the needs of body repair and muscle growth.
Introduction to Unsaturated Polyester Resin: It is an important thermosetting resin with various excellent properties. It has a wide range of applications and is used in the construction industry to produce fiberglass products such as doors, windows, decorative panels, etc; Used in the automotive industry for manufacturing body components. The advantages of use include simple molding process, low cost, and chemical corrosion resistance. However, it also faces challenges and limitations, such as relatively poor heat resistance and susceptibility to aging. During use, corresponding protective measures should be taken according to specific application scenarios, such as adding heat-resistant agents, antioxidants, etc., to extend their service life and fully leverage their advantages.
In the introduction section, elastin is a protein that plays a crucial role in the body, endowing tissues with elasticity and toughness. Its properties include high elasticity and good ductility. Elastin has a wide range of sources and is commonly found in animal connective tissues such as skin and blood vessels. When using elastin in products, the amount and method of addition should be determined based on the characteristics of the product. It has many uses and can be added to skincare products to enhance skin elasticity and reduce wrinkles; Improving food texture and enhancing taste in the food industry; In the medical field, it can be used to make elastic scaffolds such as artificial blood vessels, providing support for tissue repair. Reasonable use can play its unique value.
This document aims to guide the proper use of proteins. Proteins are the fundamental substances that make up life and are essential for maintaining normal physiological functions in the body, with a wide variety of types. When using protein, daily diet is an important source, such as meat, eggs, etc., which are rich in high-quality protein. Measuring protein intake can be done using professional tools or methods to ensure that the intake meets the body's needs. When mixing protein powder, it should be prepared according to the recommended ratio, and the water temperature should not be too high to avoid damaging the protein activity. Different groups of people have different protein requirements, such as athletes and fitness enthusiasts who can increase their intake appropriately to meet the needs of body repair and muscle growth.
Introduction to Unsaturated Polyester Resin: It is an important thermosetting resin with various excellent properties. It has a wide range of applications and is used in the construction industry to produce fiberglass products such as doors, windows, decorative panels, etc; Used in the automotive industry for manufacturing body components. The advantages of use include simple molding process, low cost, and chemical corrosion resistance. However, it also faces challenges and limitations, such as relatively poor heat resistance and susceptibility to aging. During use, corresponding protective measures should be taken according to specific application scenarios, such as adding heat-resistant agents, antioxidants, etc., to extend their service life and fully leverage their advantages.
The replication mechanism of deoxyribonucleic acid (DNA)
DNA structure
Double helix
Two strands
Antiparallel orientation
5' to 3' direction
3' to 5' direction
Complementary base pairing
Adenine with Thymine
Cytosine with Guanine
Sugar-phosphate backbone
Deoxyribose sugar
Phosphate groups
Semiconservative replication
Each strand serves as a template
Original strands
Leading strand
Lagging strand
New strands
Complementary to template strands
Replication enzymes
Helicase
Unwinds DNA double helix
Single-strand binding proteins (SSBs)
Stabilize unwound strands
Topoisomerase
Relieves supercoiling
DNA polymerase
Adds nucleotides
Proofreading activity
Corrects mismatched nucleotides
Leading strand synthesis
Continuous
Lagging strand synthesis
Discontinuous (Okazaki fragments)
RNA primase
Synthesizes RNA primers
Initiates DNA synthesis
Replication process
Initiation
Origin of replication (oriC)
Binding of initiator proteins
DnaA in E. coli
DNA unwinding
Elongation
Nucleotide addition
5' to 3' direction
Polymerase III
Leading strand
Continuous synthesis
Lagging strand
Discontinuous synthesis
RNA primers replaced by DNA
Okazaki fragments joined
DNA ligase
Termination
Replication fork convergence
Termination sites
Specific sequences
Proteins involved
Tus in E. coli
Completion of replication
Two identical DNA molecules
Each with one old and one new strand
Replication fidelity
Proofreading mechanism
3' to 5' exonuclease activity
Removes incorrectly paired nucleotides
Mismatch repair system
Corrects errors post-replication
Involves multiple proteins
MutS, MutL, MutH in E. coli
Replication in eukaryotes
Multiple origins of replication
More complex control mechanisms
Telomerase
Replicates telomeres
Specialized nucleotide sequences
At ends of chromosomes
Chromatin structure
Histone modification
Facilitates access to DNA
Chromatin remodeling
Alters DNAhistone interactions
Replication in prokaryotes
Circular DNA
No free ends
Single origin of replication
Simpler control mechanisms
Rapid cell division
High replication efficiency required
Replication regulation
Cell cycle control
Checkpoints
Ensure replication accuracy
Regulatory proteins
Initiate and terminate replication
Cyclin-dependent kinases (CDKs)
Retinoblastoma protein (Rb)
Replication errors
Mutations
Base substitutions
Insertions or deletions
Consequences
Genetic diseases
Cancer development
Uncontrolled cell division
Replication technology
Polymerase chain reaction (PCR)
Amplifies DNA segments
In vitro DNA replication
Uses heat-stable polymerases
DNA sequencing
Determines DNA nucleotide order
Fundamental in genomics
Used in research and diagnostics