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細胞和細胞結構
All About Cells and Cell Structure
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歡迎收看《基礎校園》！
All living things on earth,
地球上所有生物
from the tiniest creatures to the tallest of trees,
從最小的生物到最高的樹
are made of microscopic parts called cells.
都是由微小的細胞組成
Living things can be made of just one cell, or have many.
生物可僅由一個或很多個細胞組成
Whether it’s a plant, or an animal,
無論是植物或動物
cells are the basic structures they are composed of.
細胞是組成它們的基本結構
That’s why cells are sometimes called the 『building blocks of life!』
這就是為何細胞有時被稱為「生命的基石！」
Although there are many, many different types of cells that all have different jobs to do,
儘管不同種類的細胞有不同的分工
most cells have some things in common.
但大多數細胞有些共同點
For now, we will be dealing with two types of cells: plant cells and animal cells.
現在 我們將討論兩種類型的細胞：植物細胞和動物細胞
Both plant cells and animal cells are surrounded by a cell membrane.
動植物的細胞都是被一層細胞膜包裹
The cell membrane is a thin, flexible layer
細胞膜是一層有彈性的薄膜
that separates the inside of the cell from the outside of the cell.
將細胞內部同外界隔離開
It protects the cell,
細胞膜能保護細胞
and controls what is allowed to go in (food) and come out (waste).
並控制食物吸收和廢物排出
Plant cells have an extra layer called
植物細胞膜外還有額外的一層
a cell wall that surrounds the membrane.
即所謂的「細胞壁」
The cell wall is tough, and stronger than a membrane.
細胞壁比較堅硬 要比細胞膜更堅韌
Cell walls provide support for plants to grow and keep their shape.
細胞壁對植物生長和形狀維持起支持作用
An elephant has a skeleton to support it as it grows
大象有著一副支撐它生長的骨架
– a redwood tree doesn’t.
而紅杉沒有
Cell walls are what allows them to stand so tall.
細胞壁是支持它們長那麼高的原因
Inside the cell membrane, cells have smaller parts called organelles.
在細胞膜內 有著較小的細胞器
Organelles are like tiny organs, and they each do specific jobs inside the cell.
細胞器就像微小器官 各自在細胞裡做特定的工作
Some organelles bring in food, get rid of waste,
一些細胞器運進食物 排除廢物
repair the cell, and help it grow and reproduce.
修補細胞且幫助細胞生長和繁殖
All of the organelles are held in a special gel called cytoplasm.
所有細胞器分布在一種叫做細胞質的特殊凝膠內
Cytoplasm is usually colorless and about 80% water.
細胞質通常無色且含水量達到80%
Major organelles of a cell include the nucleus, vacuole,
細胞中主要的細胞器包括細胞核 液泡
mitochondria, ribosomes, endoplasmic reticulum, golgi apparatus,
線粒體 核糖體 內質網 高爾基體
and – only in plant cells – chloroplast.
和僅存在於植物細胞裡的葉綠體
Let’s talk about the nucleus first!
首先說說細胞核！
The nucleus is the control center of the cell, and acts kind of like the brain.
細胞核是細胞的控制中心 就像大腦一樣
The nucleus contains the DNA or genetic material
細胞核包含了DNA或遺傳物質
that determines everything about the cell
這些物質能決定細胞一切
– like what kind of cell it will be and when it will divide.
例如它會成為什麼種類的細胞和何時分裂
Next, let’s talk about the vacuole.
接著 說說液泡
Vacuoles are basically storage tanks
液泡基本上算作儲存器
that the cell uses to hold water or other materials.
被細胞用來保存水或其他物質
A plant cell usually has one large vacuole,
植物細胞通常有一個大液泡
while animal cells may have several smaller ones, called vesicles.
而動物細胞可能會有許多較小的液泡 稱為囊泡
Vacuoles are often the largest organelle in a plant cell,
植物細胞中液泡通常是最大的細胞器
and when plants do not get enough water,
當植物不能得到充足水分時
their vacuoles shrink, and the plant begins to wilt.
它們的液泡會收縮 繼而植物枯萎
Mitochondria are famously the powerhouse of the cell,
線粒體是著名的細胞能量工廠
but they are important
但它們之所以重要
because they take food and turn it into energy that the rest of the cell can use.
是因為能把食物轉換成能量 讓細胞的其餘部分可以利用
This process of using oxygen to break down sugars into chemical energy is called cellular respiration.
線粒體利用氧把糖分解成化學能的過程叫做細胞呼吸
Ribosomes are shaped like tiny balls, but work like tiny factories.
核糖體形狀像小球 但工作起來像小型工廠
They make things that the cell needs, like proteins!
核糖體合成細胞需要的物質 例如蛋白質
The cell can use proteins made by the ribosomes to build new structures,
細胞可以利用核糖體合成的蛋白質來構建新的組織
repair damage, and direct chemical reactions.
修補損傷以及指導化學反應
Some ribosomes float free in the cytoplasm,
一些核糖體游離於細胞質中
while others are attached to the endoplasmic reticulum.
而另一些則附著在內質網上
Endoplasmic reticulum, sometimes called 『ER,』 is a cellular highway!
內質網有時被稱為「ER」 是一個蜂窩狀的公路！
It’s a transportation network that takes molecules where they need to go.
它是一個運輸網絡 把分子帶到它們需要去的地方
The endoplasmic reticulum helps transport proteins made by the ribosomes to the Golgi apparatus.
內質網會將核糖體合成的蛋白質運到高爾基體
The Golgi apparatus looks a little bit like a stack of pancakes,
高爾基體有點像一疊薄餅
and it can be thought of as the post office of the cell.
並且它可以被看作細胞內的郵局
What it does is take things like proteins or other molecules that needs to be transported
高爾基體將蛋白質或其他需要被運送的分子
around or out of the cell
運往附近或細胞外
and inspects them for flaws, packages them up, and sends them where they need to go.
高爾基體將它們分揀 打包 運輸至該去的地方
Finally, let’s look at the chloroplast.
最後是葉綠體
Chloroplasts are found only in plant cells and contain chlorophyll
葉綠體僅存在植物細胞中且它含有葉綠素
– the substance that allows photosynthesis to take place.
—用以發生光合作用的物質
In photosynthesis, chlorophyll absorbs energy from sunlight
在光合作用中 葉綠素從陽光中吸收能量
and creates sugar to feed the plant.
併合成糖類供養植物
Simple plant cells may have only one or two chloroplasts in them,
簡單的植物細胞可能僅有一個或兩個葉綠體
but more complex ones may have hundreds.
但較複雜的植物細胞會有很多葉綠體
Cells and the tiny organelles inside them
細胞及其含有的微小細胞器
do the work that allows living things to live and function.
起著讓生物生存和發揮作用的功能
Without cells, there would be no life on Earth!
沒有細胞的話 世上將不會有生命！
hope you enjoyed learning about cells today. Goodbye till next time!
希望你們喜歡今天的節目 下次見！
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