cell biology

• Components of food chains

  • Animal cells
  • Plant cells
• Components of animal cells

  • Nucleus
  • Cytoplasm
  • Cell membrane
  • Mitochondria
  • Ribosomes
• Additional plant cell components

  • Chloroplasts
  • Cell wall
  • Permanent vacuole
• Nucleus


  Storing genetic information and controls cellular activities
• Cytoplasm


  Fluid component of the cell, contains organelles, enzymes and dissolved ions and nutrients
• Cell membrane


  Controls the movement of substances into and out of the cell
• Mitochondria


  Site of cellular reactions, first stage of respiration, energy production
• Ribosomes


  Site of protein synthesis
• Chloroplasts


  Site of photosynthesis
• Cell wall


  Provides structural support and protection to the cell
• Function of the nucleus - Storing genetic information and controls cellular activities
• Cytoplasm is the fluid component of the cell, it contains organelles, enzymes and dissolved ions and nutrients
• Cellular reactions occur in the cytoplasm, it is the site of the first stage of respiration and transport medium
• Endocrine glands include the pituitary gland, thyroid gland, parathyroid glands, adrenal glands (including the adrenal medulla), pancreas, ovaries/testes, and pineal gland.
• Cell membrane


  Controls entry and exit of materials into and out of the cell
• Mitochondria


  Site of later stages of aerobic respiration in which ATP is produced
• Ribosomes


  Joins amino acids in specific order during translation for the synthesis of proteins
• Plant cell wall


  Made up of cellulose
• Functions of plant cell wall

  • Provides strength
  • Prevents bursting when water enters by osmosis
• Permanent vacuole


  Contains cell sap (a solution of salts, sugars and organic acids)
• Functions of permanent vacuole

  • Supports the cell, maintaining (swollen) its turgidity
• 1mm = 1000 μm
• Difference between prokaryotic and eukaryotic cells

  Eukaryotic cells have a nucleus, whereas in prokaryotic cells DNA material is stored in nucleoid and plasmids
• When might a stain be used to view a sample of cells- when the specimen is colourless.
• The purpose of the adjustment knobs- bring object into focus by moving the stage.
• differentiation- when cells acquire special features when developing. 

• what is the function of a sperm cell- to fertilise an egg


  To carry the male DNA to the female DNA (in the egg)
• sperm


  • it has a tail to enable it to swim to the egg
  • It has lots of mitochondria to give it energy
  • It has a streamlined head to aid swimming
  • The head contains enzymes to help the sperm penetrate the egg