biology - cells (describe)

• nuclear membrane


  separates the contents from the nucleus from the rest of the cytoplasm
• golgi body


  - stores and modifies substances made by the ER for secretion - secretes substances made by the ER out of the cell
• cytoplasm


  Site of chemical reactions (most cellular activities occur here)
• chloroplasts


  site of photosynthesis in plant cells
• DNA (deoxyribonucleic acid)


  - contains hereditary information - contains information used for the cell to carry out its cellular activities
• chromosomes

  made of proteins and dna
• nucleus


  - controls all activities in a cell - contains dna
• Smooth Endoplasmic Reticulum


  - involved in detoxification - synthesises fats and steriods
• rough endosplasmic reticulum


  - transports proteins made by the ribosomes to the golgi body
• cell wall


  - gives the cell a fixed shape - protects the cell from injury
• cell membrane


  control substances moving in and out of the cell
• Ribosomes

  synthesis protein
• Mitochondria (plural)


  - site of aerobic respiration. - they break down food molecules into small substances to provide energy for the cell to carry out its cellular activities
• chloroplasts


  - contains a green pigment (chlorophyll) - can be seen under a light microscope
• vacuole (animal cells)


  - small and numerous - store food and water substances
• cell sap


  - contains dissolved substances (sugar, mineral salts and amino acids)
• vacuoles (plant cells)


  - large and central - contain a liquid (cell sap)
• smooth endoplasmic reticulum (SER)

  - more tubular, compared to RER- no ribosomes
• rough endoplasmic reticulum (RER)


  - a network of flattened spaces, lined with a membrane - appear rough due to the ribosomes attached to the surfaces
• mitochondria (plural)

  - provides energy - powerhouse of the cell - sausage-shaped organelle- break down food molecules into smaller substances during aerobic respiration
• chromosomes

  - long, thread-like structure in the nucleus - made of proteins and DNA - during cell division, it condenses and shortens into thick, rod-shaped structures
• cell wall


  - a rigid layer that surrounds the cell membrane - made of cellulose (carbohydrate)- can be seen under a light microscope
• cell membrane

  - partially permeable - allows only small and soluble substances in and out of the cell - made of lipids(fats) and proteins- can be seen under a light microscope