生命與基因

生命的存在 生命的形與體 生命的過程與奮鬥 生命的意義 生命的感覺

要是秦始皇也能夠來念生命科學系？ 或許他就可能知道長生不老的秘訣

哪些生物可以長生不老？ 壽命最長的動植物：龜、象、紅檜？ 珊瑚 怎樣才能長生不老？ 減緩衰老？ 再生？ 長生不老好嗎？ 怎樣才是好的生命？

2009諾貝爾醫學獎 http://nobelprize.org/nobel_prizes/medicine/laureates/2009/)

端粒脢telomerase Telomeres染色體終端：特異的DNA-蛋白質複合物，覆蓋在線狀染色體末端且可以保護他們以免受到傷害。 當染色體終端長度短到一個極限，有一個訊息會命令細胞停止分裂，細胞衰老隨之而起，最後進入死亡。 癌化細胞藉著再活化telomerase酵素，發展具有克服細胞死亡的機制。

Sizes in Biology tallest trees adult human chicken egg frog embryo most eukaryotic cells mitochondrion Figure: 04-01 Title: Relative sizes. Caption: Dimensions commonly encountered in biology range from about 100 meters (the height of the tallest redwoods) through a few micrometers (the diameter of most cells) to a few nanometers (the diameter of many large molecules). most bacteria virus proteins diameter of DNA double helix atoms

Animal Cell Alters 4.5

Plant Cell Plant cells have a rigid cell wall, chloroplasts, and frequently water-filled vacuoles Alters 4.6

Types of chromosomes: (1). Metacentric chromosomes中央著絲粒染色體 (2). Submetacentric chromosomes亞中央著絲粒染色體 (3). Subtelocentric (Acrocentric) chromosomes近端著絲粒染色體 (4). Telocentric chromosomes末端著絲粒染色體

Terminology for chromosome morphology (1). Metacentric chromosomes中央著絲粒染色體 (2). Submetacentric chromosomes亞中央著絲粒染色體 (3). Subtelocentric (Acrocentric) chromosomes近端著絲粒染色體 (4). Telocentric chromosomes末端著絲粒染色體 Terminology for chromosome morphology

染色體形態模型圖

著絲點與著絲粒的模式圖

一些生物種的染色體數目

人類的染色體組型（未排序前）

人類的染色體組型（排序後）

Meiotic nondisjunction

DNA半保守複製

何謂基因Gene?

Cell – Chromosome – Gene – mRNA – Protein The Central Dogma

The Flow of Genetic Information The Central Dogma – 分子生物學的中心教條: DNA RNA Protein Translation Transcription Reverse Transcription DNA Replication RNA Replication DNA  DNA DNA-dependent DNA Polymerase (DNA Replicase) DNA  RNA DNA-dependent RNA Polymerase (Transcriptase) RNA  DNA RNA-dependent DNA Polymerase (Reverse Transcriptase) RNA  RNA RNA-dependent RNA Polymerase (RNA Replicase) DNA 合成酶、轉錄酶、反轉錄酶、RNA合成酶

From DNA sequence to amino acid sequene: anticodon codon gene in DNA (template strand) (a) (b) (c) (d) mRNA (codons) tRNA (anticodons) protein (amino acids) gene Figure: 09-07a-d Title: Complementary base pairing is critical at each step in decoding genetic information Caption: (a) DNA contains two strands. One of them, the template strand, is used to synthesize an RNA molecule. (b) Bases in the template strand are transcribed into complementary mRNA codons. (c) Unless it is a stop codon, each mRNA codon forms base pairs with the anticodon of a tRNA molecule that carries a specific amino acid. (d) The amino acids are linked together, forming a protein.

Chromosome “Painting” and Trisomic 21 Trisomy 21 Incidence of ~ 1/800 Phenotype: Mental retardation Congenital heart disease Premature senility Trisomic 21 = Down Syndrome = 唐氏症

人類的性別 Sex Determination in Humans Y A -- --B B -- --A --Sry XY Female XX male Chromosome level: XX  female XY  male 2. Gene level: No Sry  female Sry  male 3. Developmental (Receptor) level 4. Psychological level