DNA AND RNA INFO Understand role of DNA in carrying the genetic code and RNA in gene expression
1. Describe the structure of DNA and RNA
DNA is a double-stranded molecule with a sugar-phosphate backbone and nitrogenous bases attached to it. The nitrogenous bases are adenine (A), guanine (G), cytosine (C), and thymine (T). DNA has a double helix structure where two strands are twisted together.
RNA is a single-stranded molecule with a sugar-phosphate backbone and nitrogenous bases attached to it. The nitrogenous bases are adenine (A), guanine (G), cytosine (C), and uracil (U) instead of thymine.
2. List the functions of DNA and RNA
DNA Functions:
- Carrying genetic information
- Replication of genetic information
- Transmission of genetic traits from one generation to another
- Storage of genetic information
RNA Functions:
- Carrying genetic information from DNA to the ribosomes for protein synthesis
- Translation of genetic information into proteins
- Regulation of gene expression
- Splicing of genetic information
Diagram:
DNA → Transcription → RNA → Translation → Proteins
Flowchart:
DNA → Replication → Chromosomes → Cell Division → Fertilization → Zygote → Development → Adult Organism
3. Explain the process of gene expression
Gene expression is the process by which the information in a gene's DNA is converted into the structures present and operating in the cell. The process of gene expression involves transcription and translation.
Transcription: The process by which the information in a gene's DNA is copied into a complementary RNA molecule.
Translation: The process by which the information in an RNA molecule is used to build a protein.
Meiosis
↓ Formation of gametes ↓ Fertilisation ↓ Formation of zygote
4. Explain the role of RNA in gene expression
RNA plays a crucial role in gene expression by carrying genetic information from DNA to the ribosomes for protein synthesis. There are three types of RNA molecules involved in gene expression:
- Messenger RNA (mRNA): carries genetic information from DNA to the ribosomes
- Transfer RNA (tRNA): carries amino acids to the ribosomes
- Ribosomal RNA (rRNA): makes up a large part of the ribosomes
Diagram:
mRNA → Ribosomes → tRNA → Amino Acids → Proteins
5. Explain the role of DNA in gene expression
DNA plays a crucial role in gene expression by providing the genetic information that is used to build proteins. The process of gene expression involves transcription and translation.
Transcription: The process by which the information in a gene's DNA is copied into a complementary RNA molecule.
Translation: The process by which the information in an RNA molecule is used to build a protein.
Diagram:
DNA → Transcription → mRNA → Translation → Proteins