2.3 Organelles
Notes
Organelles are structures that do specific jobs inside eukaryotic cells.
- Nucleus: holds DNA and controls the cell. The nucleolus inside it makes ribosome parts.
- Ribosomes: make proteins.
- Rough ER (has ribosomes) makes and moves proteins; smooth ER makes lipids and breaks down toxins.
- Golgi apparatus: modifies, sorts and packages proteins for shipping.
- Mitochondria: carry out cellular respiration to make ATP.
- Lysosomes: contain digestive enzymes that break down waste and worn-out parts.
- Vacuoles store water and materials. The cytoskeleton gives shape and helps movement.
Practice
Which organelle would be most numerous in a muscle cell that needs a lot of energy?
Mitochondria make ATP, so energy-hungry cells have many of them.
A cell makes a protein to send outside the cell. Which path does it follow?
Proteins are made on the rough ER, packaged by the Golgi, and shipped out through the membrane.
Which organelle breaks down worn-out cell parts using digestive enzymes?
Lysosomes are the cell's recycling and cleanup centers.
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