Mutation, Protein Synthesis, and DNA/RNA PDF

## Mutation - The word mutation comes from the Latin word *mutationem* which means "a changing". - A mutation is defined as the change in the DNA sequence or genes. - The DNA gene can be damaged in such a way that can change the genetic information carried by that gene. - There are many changes in t...

## Mutation - The word mutation comes from the Latin word *mutationem* which means "a changing". - A mutation is defined as the change in the DNA sequence or genes. - The DNA gene can be damaged in such a way that can change the genetic information carried by that gene. - There are many changes in the genetic sequence that may occur in mutation. ### Types of Mutation - **Gene mutation or point mutation** - **Chromosomal mutation** #### Gene mutation or point mutation - Is one of the main types of mutation. - It affects only one gene. - This type is a permanent change in the DNA sequence that makes up a gene. #### Chromosomal Mutation - Refers to a type of mutation that involves large pieces of chromosomes or the number of chromosomes in a cell. ### Types of Chromosomal Mutation - **Deletion** - happens when a chromosome is lost. - **Duplication** - occurs when a gene sequence is repeated. - **Inversion** - happens when the chromosome segment breaks off. - **Translocation** - occurs when part of one chromosome is being transferred to another chromosome. ### Types of Gene Mutation - **Substitution** - refers to a type of gene mutation where one base pair is replaced of more than one nucleotide or different amino acid. - **Insertion** - refers to the addition of one or more nucleotide base pairs into a DNA sequence. - **Deletion** - happens when a sequence of DNA is left out during DNA replication. ### The pairing of nitrogenous bases in Protein Synthesis - **Between DNA and RNA** - T - A - A - U - C - G - G - C - **Between mRNA and tRNA** - A - U - U - A - G - C - C - G ### Steps Involved in Protein Synthesis - **Transcription** is the synthesis of RNA from the information contained in DNA. - **Translation** is the actual synthesis of proteins. #### Transcription - Occurs in the nucleus. - Is catalyzed by an enzyme RNA polymerase. - One strand of DNA: TAC CAT TTG AAT CCA GTT AAC ACG ATT - mRNA: AUG GUA AAC UUA GGU CAA UUG UGC UAA #### Translation - Occurs in the cytoplasm. - tRNA: UAC CAU UUG AAU CCA GUU AAC ACG AUU - Protein: Met - Val - Asn - Phen - Gly - His - Leu - Cys - stop ### The Genetic Code - Is written in the language of nucleic acids. - It is passed on from one cell to another, from one generation to the next. - The genetic code is stored in DNA and may be expressed when copied in mRNAs. ### Protein Synthesis - In 1958, Francis HC. Crick first proposed the idea that the sequence involved in the expression of hereditary characteristics is from DNA to RNA to protein. - Involves three processes: - **Replication** - **Transcription** - **Translation** - These major critical components and processes form the basic storage, transmission, and expression of hereditary information. ### Table 1. Differences Between DNA and RNA | DNA | Characteristic | RNA | |--------------|-----------------------|--------------| | Deoxyribonucleic acid | NUCLEIC ACID | Ribonucleic acid | | Deoxyribose | SUGAR | Ribose | | A,T,C,G | NITROGEN BASES | A,C,G,U | | Double | NUMBER OF STRAND | Single | | A-T, C-G | BASE PAIRS | A-U, C-G | | | TYPES | mRNA, tRNA, rRNA | ### Types of RNA - **Messenger RNA (mRNA)** is a single strand linearly-arranged nucleotides which carries the code for a protein coding gene from DNA to ribosome. - **Ribosomal RNA (rRNA)** combines with proteins to form ribosomes. - **Transfer RNA (tRNA)** is a clover leaf-shaped RNA with attachment site for a particular type of amino acid which it carries to the ribosomes during protein synthesis.