Animal cells

• Cytoplasm

  • This is where the reactions happen and these are controlled by enzymes
  • Maintains cell shape and stores chemicals needed by the cell for metabolic reactions
  • Contains many dissolved substances
  • Is a thick gelatinous, semi-transparent fluid
  • Gelatinous fluid containing microtubules (cytoskeleton). Maintains cell shape, store of substances needed in the cell metabolism.
• Nucleus

  • Surrounded by a double membrane (envelope) with nuclear pores
  • Contains Chromatin
  • Nuclear pores allow the movement of molecules through it
  • Controls/regulates cellular activity and houses genetic material called chromatin, DNA and proteins from which comes the instruction for making proteins
  • Has double membrane containing pores. Contains DNA to control functions of the cell by coding for proteins made within the cell.
• Plasma membrane

  • Protects the cell from its surroundings
  • Allows substances in and out
  • Composed of a phospholipid bilayer, with proteins embedded in the layer
  • The membrane is selectively permeable and regulated the transport of materials into and out of the cell
  • Separates cell contents from the outside environment
  • Phospholipid bilayer with embedded proteins. Controls what can enter or leave the cell, regulates transport within the cell, separates substances from each other.
• Nucleolus


  • Region of dense DNA
  • Produces ribosomes
  • Makes RNA and ribosomes
  • Dense spherical structure in the middle of the nucleus
  • Darker portion at the centre of the nucleus. Area where RNA and ribosomes are made.
• Ribosomes


  • These make proteins
  • 80s in Eukaryotic cells
  • Protein synthesis occurs at the ribosomes
  • Tiny organelles attached to rough ER or free floating in the cell
  • They consist of two sub-units and they are not surrounded by a membrane an be attached to rough ER or free in the cytoplasm. Joins amino acids to each other, in the order determined ultimately by DNA, to synthesise proteins.
• Rough Endoplasmic Reticulum (ER)

  • Flattened sacs with a membrane covered in ribosomes
  • This is where proteins are made
  • Protein synthesis takes place on the ribosomes and the newly synthesised proteins are transported to the Golgi apparatus
  • Network of membrane bound flattened sacs called cisternae studded with ribosomes
  • Made of plasma membrane arranged in a network of sacs called cisternae. Membrane studded with ribosomes for protein synthesis. Transports these proteins to the Golgi apparatus for finishing.
• Smooth Endoplasmic Reticulum (ER)

  • Membranes tubes
  • This is where lipids are made
  • Network of membrane bound flattened sacs called cisternae (No Ribosomes)
  • Responsible for synthesis and transport of lipids and carbohydrates
  • Similar to rough ER but without the ribosomes. Synthesises lipids and carbohydrates.
• Vesicles 


  • Small spherical membrane bound sacs with fluid inside
  • Transport vesicles are used to transport material inside the cell and secretory vesicles transport proteins that are to be released from the cell, to the cell surface membranes
  • Small membrane bound sacs for storing and transporting substances in the cell
  • Spherical membrane-bound sacs which contain fluid and substances such as proteins made in the Golgi apparatus or substances that have entered the cell. Used for transport of substances.
• Golgi apparatus 


  • Modifies proteins and packages them in vesicles for transport
  • A stack of membrane bound flattened sacs
  • Newly made proteins are received here from the rough ER. The Golgi apparatus modifies them and then packages the proteins into vesicles to be transported to where they are needed.
  • Stacks of sacs made of plasma membrane with vesicles coming off it. Modified proteins by adding non-protein components. Packages them into vesicles for transport elsewhere inside or outside the cell.
• Lysosomes 


  • Enclosed by a single membrane
  • Contains digestive enzymes
  • Destroys old organelles and pathogens
  • Small spherical membrane bound sacs containing hydrolytic enzymes
  • They break down waste material including old organelles
  • Type of vesicle which contains the enzyme lysozyme a hydrolytic enzyme which breaks down waste material including old organelles and also invading pathogens.
• Centrioles 


  • 2 hollow tubes at right angles to each other
  • They make the spindle in cell division
  • They are small tubes of protein fibres
  • They form spindle fibres during cell division
  • Made of microtubules arranged in 9 sets of 3. They form spindle fibres used to separate genetic material during cell division.
• What is the primary function of mitochondria?

  ATP production through respiration
• Why do mitochondria have a double membrane?

  To compartmentalize processes and increase efficiency
• What is the purpose of the folded projections in the inner membrane of mitochondria?

  To increase the surface area for ATP production
• What is the jelly-like substance found in the central area of mitochondria called?

  Matrix
• What important components are contained within the matrix of mitochondria?

  Ribosomes and DNA
• How do the shapes of mitochondria vary?

  They can be long or spherical depending on the angle
• What are the final stages of cellular respiration located?

  In the mitochondria
• What is the significance of the cristae in mitochondria?

  They increase the surface area of the inner membrane
• What is the aerobic portion of cellular respiration located?

  In the matrix of mitochondria
• How many membranes do mitochondria have?

  Two membranes
• What is the role of the inner membrane in mitochondria?

  It is highly folded to form cristae
• What is the central part of the mitochondria called?

  Matrix
• What happens in the matrix of mitochondria?

  Aerobic portion of cellular respiration occurs
• How does the structure of mitochondria support its function?

  Folds increase surface area for ATP production