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1. Introduction to Anatomy & Physiology5h 43m
2. Cell Chemistry & Cell Components12h 36m
3. Energy & Cell Processes10h 6m
4. Tissues & Histology10h 3m
5. Integumentary System2h 20m
6. Bones & Skeletal Tissue2h 16m
7. The Skeletal System2h 35m
8. Joints2h 17m
9. Muscle Tissue2h 33m
10. Muscles1h 11m
11. Nervous Tissue and Nervous System1h 35m
12. The Central Nervous System1h 6m
- Introduction to the Central Nervous System
  18m
- The Cerebrum
  48m
13. The Peripheral Nervous System1h 26m
14. The Autonomic Nervous System1h 38m
15. The Special Senses2h 41m
16. The Endocrine System2h 48m
17. The Blood3h 22m
18. The Heart2h 42m
19. The Blood Vessels3h 35m
20. The Lymphatic System3h 16m
21. The Immune System14h 37m
22. The Respiratory System3h 20m
23. The Digestive System2h 5m
24. Metabolism and Nutrition4h 0m
25. The Urinary System2h 39m
26. Fluid and Electrolyte Balance, Acid Base Balance37m
27. The Reproductive System2h 5m
28. Human Development1h 21m
29. Heredity3h 32m

3. Energy & Cell Processes

Central Dogma

3. Energy & Cell Processes

Central Dogma: Videos & Practice Problems

Video Lessons Practice Worksheet

Topic summary

The central dogma of biology describes the unidirectional flow of biochemical information from DNA to protein, encompassing two key processes: transcription and translation. Transcription synthesizes messenger RNA (mRNA) from DNA, while translation converts mRNA into proteins. This process is irreversible; once nucleic acid information is transformed into protein, it cannot revert to nucleic acids. Additionally, DNA can replicate itself, and reverse transcription allows RNA to form DNA in specific scenarios. Understanding these processes is crucial for grasping gene expression and the fundamental mechanisms of molecular biology.

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Central Dogma

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Central Dogma Video Summary

The Central Dogma of Biology describes the unidirectional flow of genetic information from DNA to protein, emphasizing that this process is one-directional, meaning information cannot flow back from protein to DNA. This flow occurs through two main processes: transcription and translation.

Transcription is the first step, where RNA is synthesized using DNA as a template. The specific type of RNA produced during this process is messenger RNA (mRNA). This mRNA carries the genetic information necessary for the next step.

The second step, translation, involves the conversion of the mRNA sequence into a protein. During translation, ribosomes read the mRNA and synthesize proteins based on the encoded information. Together, transcription and translation are often referred to as gene expression, which is the process by which a gene's information is used to produce a functional product, typically a protein.

It is also important to note that DNA can undergo replication, which is the process of creating an identical copy of DNA using the original DNA as a template. Additionally, reverse transcription is a process where RNA is used to synthesize DNA, allowing for the conversion of mRNA back into DNA in certain circumstances. However, while DNA can be transcribed into RNA and RNA can be reverse transcribed into DNA, the conversion of nucleic acids into proteins is irreversible. Once the information has been translated into protein, it cannot be used to synthesize nucleic acids.

In summary, the Central Dogma illustrates the flow of genetic information from DNA to RNA to protein, highlighting the processes of transcription and translation, while also acknowledging the possibility of DNA replication and reverse transcription. Understanding these processes is crucial for grasping how genetic information is expressed and utilized within biological systems.

Problem

According to the central dogma, what is the intermediate molecule involved in the flow of information in a cell that should go in the blank? DNA → ________ → Proteins

Ribosome.

rRNA.

mRNA.

tRNA.

Problem

The full process by which genotype becomes expressed as phenotype is called:

Transcription.

Translation.

DNA Replication.

Gene expression.

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What is the central dogma of molecular biology?

The central dogma of molecular biology describes the unidirectional flow of genetic information from DNA to RNA to protein. This process involves two main steps: transcription and translation. During transcription, DNA is used as a template to synthesize messenger RNA (mRNA). In translation, the mRNA is then used to build proteins. This flow of information is irreversible, meaning that once the information is converted into protein, it cannot revert back to nucleic acids. Understanding this concept is fundamental for grasping how genes are expressed and how genetic information is utilized within cells.

What are the steps involved in the central dogma?

The central dogma involves two key steps: transcription and translation. In transcription, DNA serves as a template to synthesize messenger RNA (mRNA). This process occurs in the nucleus of eukaryotic cells. The mRNA then exits the nucleus and enters the cytoplasm, where translation occurs. During translation, ribosomes read the mRNA sequence and use it to assemble amino acids into a polypeptide chain, forming a protein. These steps are crucial for gene expression, allowing the genetic information stored in DNA to be converted into functional proteins.

What is the role of mRNA in the central dogma?

Messenger RNA (mRNA) plays a critical role in the central dogma of molecular biology. It acts as an intermediary between DNA and protein synthesis. During transcription, mRNA is synthesized from a DNA template. This mRNA carries the genetic code from the DNA in the nucleus to the ribosomes in the cytoplasm, where translation occurs. In translation, the mRNA sequence is read by ribosomes to assemble amino acids into a specific protein. Thus, mRNA is essential for transferring genetic information from the nucleus to the site of protein synthesis.

Can RNA be reverse transcribed into DNA?

Yes, RNA can be reverse transcribed into DNA through a process known as reverse transcription. This process uses an enzyme called reverse transcriptase to synthesize complementary DNA (cDNA) from an RNA template. Reverse transcription is not part of the central dogma's unidirectional flow but occurs in specific scenarios, such as in retroviruses like HIV. Understanding reverse transcription is important for studying viral replication and certain biotechnological applications, such as creating cDNA libraries for gene expression studies.

Why is the flow of information from nucleic acids to proteins considered irreversible?

The flow of information from nucleic acids (DNA and RNA) to proteins is considered irreversible because, once the genetic information is translated into a protein, it cannot be converted back into nucleic acids. This unidirectional flow is a fundamental principle of the central dogma of molecular biology. Proteins do not serve as templates for the synthesis of nucleic acids. This irreversibility ensures that the genetic information is faithfully transmitted and expressed without the risk of back-conversion, maintaining the integrity of the genetic code.