What are cells made of?

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Organelles

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The Nucleus

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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

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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