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標題: 香港電台 五夜講場 - 真係好科學 2020:細胞三世書 [打印本頁]

作者: fossilshk    時間: 2020-7-28 05:45 AM     標題: 香港電台 五夜講場 - 真係好科學 2020:細胞三世書

有沒有想過,若果地球誕生之初只是一堆高溫的鹽、水和氣體混合物,中間究竟發生了甚麼事,才演變出現在複雜的細胞生命體?無機的化合物能夠被「烹煮」成氨基酸、脂肪和核酸這些組成生命的基礎化合物嗎?為甚麼說 RNA 或許是所有生物的共同祖先?從無生命演化出細胞的故事,在地球史上是否只出現過一種版本?今集《細胞三世書》,主持會提出各種新奇的理論和證據,拆解地球上一切生命的前傳故事。

主持:
陳志宏(紐約大學物理學系博士)
麥嘉慧(香港大學理學院講師)
馬學綸(香港中文大學微生物學博士)
吳家亮(香港中文大學分子生物技術學博士)


作者: fossilshk    時間: 2020-7-28 05:48 AM     標題: 疊層石

今集會講到生命起源...
其中有我們提供的疊層石化石講解, 正確時間大概是二十七億年前

圖片附件: 疊層石.jpg (2020-7-28 05:49 AM, 86.27 K) / 該附件被下載次數 434
https://fossilshk.com/forum/attachment.php?aid=9869


作者: c7    時間: 2020-8-2 02:22 AM

聽左啲
其實生命即係點樣黎??
作者: Dinosaurprince    時間: 2020-8-7 04:10 AM     標題: 回復 #3 c7 的帖子

There is no scientific consensus. But the major hypothesis stated RNA and other "building block of life" was synthesised in some stable hydrothermal vent like the Lost City. Volcano gas in those vent provides elements such as carbon dioxide, sulphur, and nitrogen to form some organic molecules. The volcanic activities also provide the alkaline environment to generate pH gradients similar to the pH gradients across mitochondria membranes. In this way, the hydrogen ion  may provide energy for the the biochemical reaction similar to cell today. In addition, the porous compartment provide semi-permeable condition for RNA activities before cell membrane evolution and some minerals in those vent can act as catalyst for biochemical before the evolution of ribozyme and enzyme. It is possible that RNA first appear and have their Darwinian natural selection in the RNA world scenario with the help of mineral catalyst. Some RNA evolved the ability to catalyse their RNA synthesis as ribozyme and eventually the ability to synthesis protein  and DNA. and lastly, cell membrane evolved seperately in eubacteria and archaean clade
作者: megalodon    時間: 2020-8-12 03:51 AM



QUOTE:
原帖由 Dinosaurprince 於 2020-8-7 04:10 AM 發表
There is no scientific consensus. But the major hypothesis stated RNA and other "building block of life" was synthesised in some stable hydrothermal vent like the Lost City. Volcano gas i ...
Professional guy




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