Cells
Introduced| English | Meaning |
|---|---|
| cells/selz/ | The smallest structural and functional unit of a living organism. |
| cell membrane/sel ˈmembreɪn/ | The selectively permeable boundary surrounding a cell and controlling movement of substances into and out of it. |
| cytoplasm/ˈsaɪtəplæzəm/ | The contents of a cell inside its membrane and outside the nucleus, where many chemical reactions occur. |
| nucleus/ˈnjuːklɪəs/ | A membrane-bound organelle in eukaryotic cells that contains most of the genetic material. |
| mitochondria/ˌmaɪtəˈkɒndrɪə/ | Organelles in eukaryotic cells where most aerobic respiration and ATP production occur. |
| cell wall/sel wɔːl/ | A supportive layer outside the cell membrane in plants, fungi and many microorganisms. |
| cellulose/ˈseljuːləʊs/ | A structural polysaccharide made of glucose units, forming a major component of plant cell walls. |
| chloroplasts/ˈklɔːrəʊplæsts/ | Organelles in plants and algae that contain photosynthetic pigments and carry out photosynthesis. |
| chlorophyll/ˌklɔːrəʊˈfɪl/ | A green pigment that absorbs light energy for photosynthesis. |
| vacuole/ˈvækjuːəʊl/ | A membrane-bound compartment containing fluid and dissolved substances, often large and permanent in plant cells. |
The building blocks of life
- Every living thing — from a blade of grass to a blue whale — is built from cells 细胞.
- They are tiny, but inside each one is a busy world of parts that keep it alive.
Which part of the cell contains DNA and controls the cell?
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The nucleus holds DNA and controls the cell.
Which part releases energy by respiration?
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Mitochondria are the site of aerobic respiration.
The cell membrane's main job is to:
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The membrane controls movement in and out.
Parts of an animal cell
- Cell membrane 细胞膜: controls what enters and leaves.
- Cytoplasm 细胞质: jelly where reactions happen.
- Nucleus 细胞核: contains DNA and controls the cell.
- Mitochondria 线粒体: release energy by respiration.
An animal cell: membrane, cytoplasm, nucleus, mitochondria and ribosomes
Explore the parts of a cell
Tap each part of the cell to see what it does. Some parts (cell wall, chloroplast, vacuole) are found only in plant cells.
Which parts are found ONLY in plant cells? (Select all that apply.)
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The nucleus is in both; the cell wall, chloroplasts and large vacuole are plant-only.
The plant cell part made of cellulose that gives support is the cell ______.
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The cellulose cell wall supports and shapes plant cells.
Extra parts in a plant cell
- Cell wall 细胞壁: made of cellulose 纤维素, gives support and shape.
- Chloroplasts 叶绿体: contain chlorophyll 叶绿素 for photosynthesis.
- Large vacuole 液泡: filled with cell sap, keeps the cell firm.
Onion epidermis cells under a light microscope — each cell has a clear cell wall
Animal vs plant cells
- Both have a membrane, cytoplasm, nucleus and mitochondria.
- Only plant cells have a cell wall, chloroplasts and a large permanent vacuole.
All plant cells have a cell wall, but not all have chloroplasts. Root cells, for example, are underground and get no light, so they have no chloroplasts. Don't assume every plant cell is green.
A plant cell also has a cell wall, a large vacuole and chloroplasts
You've got it
- all cells have a membrane, cytoplasm, nucleus and mitochondria
- plant cells also have a cell wall, chloroplasts and a large vacuole
- the nucleus controls the cell; mitochondria release energy