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What are cells made of? The World of Cells 1
What are cells made of?
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Organelles
The World of CellsThe World of Cells
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The Nucleus
The World of CellsThe World of Cells
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• In the cells of organisms except bacteria, the hereditary material is in an organelle called the nucleus (NEW klee us).
The Nucleus
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• Inside the nucleus are chromosomes (KROH muh zohmz).
• Chromosomes contain an important chemical called DNA. It determines which traits an organism will have.
nucleus
• Controls all cell activities
• Has heredity information in chromosomes and DNA
Energy and the Cell
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• Cells, except bacteria, have organelles called mitochondria (mi tuh KAHN dree uh).
• An important process called cellular respiration takes place inside a mitochondrion.
mitochondria
• Turns food into energy
Storage
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• In cells, food, water, and other substances are stored in balloonlike organelles in the cytoplasm called vacuoles (VA kyuh wohlz).
• Some vacuoles store wastes until the cell is ready to get rid of them.
vacuole
• Storage
• Holds water and disposes wastes
Inside the Cell
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• The inside of a cell is filled with a gelatinlike substance called cytoplasm (SI tuh pla zum).
• Approximately two-thirds of the cytoplasm is water, but it also contains many chemicals that are needed by the cell.
cytoplasm
• Gel-like substance
• Has water and important chemicals
chromosomes
• In nucleus
• has heredity information-DNA
Outside the Cell
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• The cell membrane is a flexible structure that holds the cell together.
• The cell membrane forms a boundary between the cell and its environment.
Cell membrane
• Surrounds cell
• Controls what passes in and out of cell
Nature's Solar Energy Factories
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• Most photosynthesis in plants occurs in leaf cells.
• Inside these cells are green organelles called chloroplasts (KLOR uh plats).
Nature's Solar Energy Factories
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• Animals obtain food from their surroundings.
• Plants, algae, and many types of bacteria make food through a process called photosynthesis (foh toh SIHN thuh sus).
Nature's Solar Energy Factories
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• During plant photosynthesis chloroplasts capture light energy and combine carbon dioxide from the air with water to make food.
• As the plant needs energy, its mitochondria release the food's energy.
chloroplast
• Conducts photosynthesis
• Found mostly in leaf cells
• Contains chlorophyll-green color
Outside the Cell
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• Some cells also have a structure outside the cell membrane called a cell wall.
• The cell wall helps support and protect these cells.
Cell wall
• Provides support and protection
• Plant cell only
Plant cells vs. animal cells
Plant cell Animal cell Both cells
Organelles
The World of CellsThe World of Cells
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• Except for bacterial cells, cells contain organelles (or guh NELZ).
• These specialized cell parts can move around in the cytoplasm and perform activities that are necessary for life.
organelles
• Parts of the cell that have a specific job
• Inside the cell in the cytoplasm
• Organelles
• Not organelles
