AQA A Level Biology復習筆記4.1.4 Genes
The Definition of a Gene
- A?gene?is a base?sequence of DNA?that codes for the?amino acid sequence of a polypeptide?or a?functional RNA molecule
- Functional RNA molecules are required for protein synthesis
- mRNA - the base sequences on messenger RNA molecules are used by ribosomes to form polypeptide chains
- tRNA - amino acids are carried to the ribosome by transfer RNA molecules
- rRNA - ribosomal RNA molecules form part of the structure of ribosomes
- The?shape?and?behaviour?of a protein molecule depends on the?exact sequence?of these amino acids (the initial sequence of amino acids is known as the?primary structure?of the protein molecule)
- The?genes in DNA molecules, therefore, control protein structure?(and as a result, protein function) as?they determine the exact sequence in which the amino acids join together?when proteins are synthesised in a cell
A gene is a sequence of nucleotides that codes for the production of a specific protein molecule (polypeptide)
Exam Tip
One gene codes for one mRNA molecule, which codes for one polypeptide. This is known as the central dogma of molecular biology.Remember – each chromosome in a human cell nucleus contains one very long DNA molecule. This DNA molecule is made up of thousands of specific nucleotide sequences called genes that code for specific proteins. Even though these genes are all found within the same DNA molecule and are therefore all linked up, the cell knows where individual genes start and stop. This ensures the cell reads the DNA correctly and can produce the correct protein molecules that it requires to function properly.
轉載自savemyexams
以上就是關于【AQA A Level Biology復習筆記4.1.4 Genes】的解答，如需了解學校/賽事/課程動態，可至翰林教育官網獲取更多信息。
往期文章閱讀推薦：
翰林獨家 | 經濟學競賽核心精講，一冊打通NEC/IEO/USAEBO！
2026 ALEVEL 夏考A率出爐！愛德思vs牛津AQA，哪些科目真的“好出分”？
翰林AMC8視頻課重磅上線！
國際競賽真題資源免費領取
