cell strucutre

• Parts of an animal cell visible under a light microscope

  • Nucleus
  • Cytoplasm
  • Cell membrane
• Additional features of eukaryotic cells not visible under a light microscope (Higher/Supplement)

  • Ribosomes
  • Mitochondria
  • Rough endoplasmic reticulum
  • Vesicles
• Ribosomes


  The site of protein synthesis
• Rough endoplasmic reticulum


  Studded with ribosomes and involved in producing and transporting proteins
• Mitochondria


  The powerhouse of the cell, produces energy in the form of ATP by carrying out aerobic respiration
• Vesicles


  Used to transport substances within cells
• A very metabolically active cell

  Likely to have lots of mitochondria as they produce energy through aerobic respiration
• Cells that have rough endoplasmic reticulum and mitochondria

  • Almost all cells except prokaryotic cells like bacteria
• Parts of a plant cell visible under a light microscope

  • Nucleus
  • Cytoplasm
  • Chloroplasts
  • Vacuoles
  • Cell wall
  • Cell membrane
• Nucleus


  Controls the cell and contains genetic material in the form of chromosomes
• Cytoplasm


  Where most of the cell's chemical reactions take place
• Organelles only found in plant cells

  • Cellulose cell wall
  • Permanent vacuole
  • Chloroplasts
• Cell wall


  Provides strength and support, made of cellulose
• Permanent vacuole


  Supports the cell and contains cell sap (a solution of sugars and salts)
• Chloroplasts


  The site of photosynthesis
• Ciliated epithelial cells


  Waft away dirt and debris up the throat where it can be swallowed
• Ciliated epithelial cells


  • Small cilia that line the exposed surface can waft back and forwards
  • The cilia are long and thin so that lots of them can waft at the same time
• Root hair cells


  Take up minerals and water needed by the plant
• Root hair cells


  • Have lots of mitochondria to provide energy for active transport
  • Have a long extension to maximise the surface area available for uptake
• Xylem vessels


  Transport water from the roots to the shoots and support the plant
• Xylem vessels


  • Waterproofed and strengthened with a substance called lignin
  • Small diameter so a continuous column of water is maintained
  • Dead cells without organelles so that the flow of water is not interrupted
• Palisade mesophyll cells


  Their main function is to absorb light and carry out photosynthesis
• Palisade mesophyll cells


  • Contain lots of chloroplasts to carry out photosynthesis
  • Thin and tall so that many can be packed together
  • Large vacuole pushes chloroplasts to the outside of the cell
  • Thin cell wall to minimise the diffusion distance
• Red blood cells


  Carry oxygen from the lungs to tissues and carbon dioxide from tissues to the lungs to be exhaled
• Red blood cells


  • No nucleus so there is more room for haemoglobin
  • Contain lots of haemoglobin to carry oxygen
  • Biconcave shape giving a large surface area to volume ratio
  • Thin membrane to minimise the diffusion distance for gases
• Nerve cells


  Pass nervous impulses quickly from one part of the body to another
• Nerve cells


  • Long extensions to connect different parts of the body
  • Insulated with myelin sheath to increase speed of impulse transmission
  • Many mitochondria to provide energy for impulse transmission
• Red blood cells


  • No nucleus so there is more room for haemoglobin
  • Contain lots of haemoglobin to carry oxygen
  • Biconcave shape giving a large surface area to volume ratio
  • Thin membrane to minimise the diffusion distance for gases
• Function of nerve cells

  To pass nervous impulses quickly from one part of the body to another
• Nerve cells


  • Ends contain neurotransmitters to send impulses to other neurones
  • Long axon to transmit impulses long distances
  • Thin to transmit impulses faster
  • Enclosed in a myelin sheath to speed up transmission
• Function of sperm cell

  To travel to, penetrate and fertilise an egg cell
• Sperm cell


  • They contain a long tail to help it swim to the egg
  • They have a middle section containing lots of mitochondria which provide the cell with energy for swimming to the egg
  • They have an acrosome at the tip containing enzymes to digest the outer membrane of the egg
• Function of egg cell

  To fuse with a sperm cell for reproduction
• Egg cell


  • Haploid nucleus so that after fusing with a sperm it produces a diploid organism
  • Lots of cytoplasm for many divisions
  • Lots of nutrients to support the egg until it reaches the womb
• Tissue


  A group of cells working together to carry out a specific function
• Organ


  A group of tissues working together to carry out a specific function
• Organ system


  A group of organs working together to carry out a specific function
• 3 organ systems in the body

  • The respiratory system
  • The circulatory system
  • The reproductive system
• Tissues that make up a plant leaf

  • Mesophyll tissue (spongy mesophyll and palisade mesophyll)
  • Epidermis (upper and lower)
  • Veins (xylem and phloem)
• Organs that make up the circulatory system

  • The heart
  • The lungs
  • The blood vessels