2023AP考试报名，香港今日截止，韩国倒计时，新加坡第二轮开启！
重要消息！重要消息！ 香港AP考试报名今日截止 韩国即将于11月8日截止 新加坡第二轮AP报名已开启 香港考区新增考位，今日截止报名 香港考场于10月31日新增7门科目报考名额，还没有抢到考位的同学和家长抓紧最后的...
Edexcel A (SNAB) A Level Biology:复习笔记2.3.5 Levels of Protein Structure
Levels of Protein Structure There are four levels of structure in proteins Three are related to a single polypeptide chain The fourth level relates to a protein that has two or more polypeptide cha...
Edexcel A (SNAB) A Level Biology:复习笔记2.3.4 Amino Acids & Peptide Bonds
Amino Acid: Structure Proteins Proteins are polymers (and macromolecules) made of monomers called amino acids The sequence, type and number of the amino acids within a protein determines its shape ...
Edexcel A (SNAB) A Level Biology:复习笔记2.3.3 Nature of the Genetic Code
Nature of the Genetic Code The triplet code The sequence of DNA nucleotide bases found within a gene is determined by a triplet (three-letter) code Each sequence of three bases (i.e. each triplet o...
Edexcel A (SNAB) A Level Biology:复习笔记2.3.2 Translation
Translation Translation occurs in the cytoplasm of the cell After leaving the nucleus via a nuclear pore, the mRNA molecule attaches to a ribosome In the cytoplasm there are free molecules of tRNA ...
Edexcel A (SNAB) A Level Biology:复习笔记2.3.1 Transcription
Transcription A gene is a sequence of nucleotide bases in a DNA molecule that codes for the production of a specific sequence of amino acids, that in turn make up a specific polypeptide (protein) T...
Edexcel A (SNAB) A Level Biology:复习笔记2.2.3 RNA: Structure
RNA: Structure Like DNA, the nucleic acid RNA (ribonucleic acid) is a polynucleotide – it is made up of many nucleotides linked together in a chain Like DNA, RNA nucleotides contain the nitrogenous...
Edexcel A (SNAB) A Level Biology:复习笔记2.2.2 DNA: Structure
DNA: Structure The nucleic acid DNA is a polynucleotide – it is made up of many nucleotides bonded together in a long chain DNA nucleotide DNA molecules are made up of two polynucleotide str...
Edexcel A (SNAB) A Level Biology:复习笔记2.2.1 Nucleotides & Phosphodiester Bonds
Mononucleotides: Structure Both DNA and RNA are polymers that are made up of many repeating units called nucleotides Each nucleotide is formed from: A pentose sugar (a sugar with 5 carbon atoms) A ...
