Where does the cell get the energy to do all this? That’s the role of the mitochondria. To make energy, the mitochondria take oxygen. This is the only reason why we breathe in, and adds electrons from the food we eat to make water molecules. That process also creates a high energy molecule called ATP, which the cell uses it to power all of its parts. Plant cells make energy a different way. They have chloroplasts. They combine carbon dioxide and water with light energy from the sun to create oxygen and sugar, a form of chemical energy. All the parts of the cell have to work together to keep things running smoothly. And all the cells of your body have to work together to keep you running smoothly. That’s a whole lot of cells. Scientists think there’re about 37 trillion of them.
細胞實現(xiàn)這些功能的能量從何而來？那是線粒體發(fā)揮了作用。為了制造能量，線粒體吸進氧氣。這是我們吸入氧氣的唯一原因，然后從我們攝入的食物中獲取電子來制造水分子。這個過程同時制造出一個高能量分子，叫做三磷酸腺苷，它為細胞其他部分的運作提供能量。植物細胞的能量來源不同。它們有葉綠體。葉綠體把二氧化碳和水分與太陽光能量合成，制造氧氣和糖分，一種化學能量。細胞所有部分必須得一起工作才能保證功能正常。你體內(nèi)所有的細胞也必須一起工作使你一切正常。人體內(nèi)有很多細胞?？茖W家們認為人體內(nèi)有37萬億個細胞。
詞匯講解：
mitochondria ?/?ma?t??kɑndri?/ ?pl.?線粒體
mitochondrion /?ma?to??kɑ?ndri?n/?s.
*phenomena & phenomenon????現(xiàn)象
combine…and/with…
把……和……組合在一起
work together to…
一起努力去……
keep you running smoothly
讓你的身體運行流暢
a whole lot of很多
關于數(shù)字：
trillion ?
1000,000,000,000
1 trillion = 1000 billion
1 billion = 1000 million
1 million = 1000 thousand
