Cell structure and organelles

Organelles and functions

• Nucleus: contains chromosomes (DNA); controls cell activities.
• Cell membrane: semi-permeable; controls movement of substances.
• Cytoplasm: site of many chemical reactions.
• Mitochondria: site of aerobic respiration; release energy (ATP). Numerous in active cells such as muscle and sperm cells.
• Ribosomes: protein synthesis.
• Endoplasmic reticulum: rough ER (with ribosomes) transports proteins; smooth ER makes lipids.
• Golgi apparatus: packages and secretes substances.
• Lysosomes: contain enzymes that break down worn-out organelles and germs.
• Chloroplasts (plants): photosynthesis.
• Cell wall (plants): cellulose; gives shape and support.
• Large central vacuole (plants): stores cell sap; maintains turgidity.