Cell structure

• What is the function of the nucleus?

  It controls the activity of a cell and contains the most of the cell’s DNA, in the form of chromatin/chromosomes
• What does the nucleolus do?

  Produces RNA and ribosomes
• What are ribosomes made out of?

  rRNA and protein
• What are the two types of ribosomes?

  (80s) ribosomes [eukaryotes]

  (70s) ribosomes [prokaryotes]
• What is the function of the golgi body?

  Processes proteins by adding non protein groups

  Repackages the proteins into vesicles

  Produces lysosomes
• What is the function of a vesicle?(and the different types)

  Transport vesicle- transports molecules between organelle

  Excretory vesicle- transports molecules to the plasma membrane to excrete them from the cell
• What is the process of excreting molecules from a cell?

  Exocytosis
• What is a Lysosome and what does it do

  A lysosome is a specialised vesicle

  It digests pathogens/cell waste using hydrolytic enzymes
• Rough endoplasmic reticulum (RER) structure

  Folded membrane bound sacs, studded with ribosomes
• What is the function of the RER?

  Transport of proteins made by the attached ribosomes

  Site of protein synthesis
• Smooth endoplasmic reticulum structure

  A series of tubular membrane bound sacs
• Function of smooth endoplasmic reticulum

  Synthesis of lipids and carbohydrates
• Mitochondria structure

  A double membrane organelle

  Inner membrane folded to form cristae

  The fluid inside the inner membrane is known as the matric

  Ribosomes and starch grains are held within this matrix

  It also contains a small amount of DNA known as mitochondrial DNA (mDNA)

  
• What is the function of mitochondria?

  It is the site of aerobic respiration producing ATP
• Chloroplast structure

  They have a double phospholipid membrane (like mitochondria)

  -These are seperated by a inner membrane

  A third membrane called the thylakoid membrane folded into thylakoid discs (flattened sacs)

  Thylakoids discs are stacked to form a granum
• Where is chlorophyll present in chloroplasts

  Thylakoid membranes

  Intergranal lamella
• What is the function of chloroplasts?

  Photosynthesis (the use of light to produce ATP)
• Where does photosynthesis take place?

  The early stages occur in the thylakoid discs producing ATP

  Enzymes in the stroma then use the ATP to make sugar from fixed carbon dioxide producing carbohydrates
• How are carbohydrates stored?

  They are temporarely stored as starch grains
• Plasma membrane function

  Regulates movement of substances in and out of the cell (partially permiable)

  Has receptors to allow cell signalling
• Centrioles structure

  Small tubes made of microtubuels in a 9 × 3 arrangement
• Function of centrioles

  Involved in the formation of spindle fibres
• Cilia structure

  Small (less than 10micrometers)

  Made of a membrane surrounding a 9 + 2 arrangement of microtubuels (9 pairs in a circle around a centeral pair)

  The basal body (base) has the same microtubule arrangement as a centriole 9×3
• What is an undulipodia

  A eukaryotic version of the flagella

  They could be found in some eukaryotic cells

  They are used for movevment
• What is a flagella

  Flagella are similar to undulipodia

  -they look the same

  -they have the same function for movement
• What is the difference between flagella and undulipodia

  Undulipodia have the same structure as cilia

  flagella have a different internal structure

  A long spiral of protein called flagellin is attached to a protein disc at the base

  -The disk rotates (using ATP) spinning the flagellum

  
• Cell wall function

  To support and protect the cell
• What are plant cell walls made out of?

  cellulose
• What are fungal cell walls made out of?

  chitin
• What are prokaryotic cell walls made out of?

  peptidoglycan (also called murein)