Eukaryotic cells

• What is the function of the nucleus?


  Controls cells' chemical activities by protein synthesis
• What are histones?

  DNA binding proteins
• What are the features of the nucleus?

  Large

  Has a double membrane
• What is the nucleoplasm?


  Jelly substance inside the nucleus
• What is the Nuclear envelope?

  The double membrane of the nucleus'
• What do nuclear pores do?

  They allow the passage of large molecules
• What does the nucleolus contain?

  The DNA for synthesising RNA and assembles ribosomes
• What is the chromatin?

  DNA associated with proteins is spread out amongst the nucleoplasm.
• What does the mitochondria do?

  Where most of aerobic respiration happens

  Produces ATP molecules
• What are the features of the mitochondria and what do they do?

  Double membrane - controls what goes in and out

  Matrix - Contains substances so it can synthesise it's own proteins

  Cristae - Provides large SA for respiration reactions
• What are lysosomes made by?

  The golgi body
• What are lysosomes? 


  Vesicles that contain lytic enzymes
• What do the lysosomes break down?

  material ingested by phagocytic cells

  worn out organelles

  dead cells

  material outside the cell by releasing their enzymes by exocytosis
• What is the Golgi body made out of?


  Stacks of flattened sacs (cisternae)
• What does the Golgi body do?

  Makes secretory enzymes

  Forms glycoproteins

  Forms lysosomes

  Receives substances from ER and modifies them before they are secreted
• Where are ribosomes found?


  Found in the cytoplasm, but usually attached to endoplasmic reticulum
• What do ribosomes do?

  Synthesise proteins from mRNA
• What are the two types of ribosomes?

  80s - in eukaryotic cells

  70s - in prokaryotic cells
• What is the RER made out of?


  flattened sacs called cisternae
• What does the RER do?

  The Ribosomes attached to RER make proteins for secretion

  RER provides a pathway for the transport of materials

  through the cell
• What is the SER made out of?


  Flattened sacs more tube-shaped than RER
• What do SER NOT have in compared to the RER?

  The SER doesn't have ribosomes
• What does the SER contain?

  Enzymes of lipid metabolism
• What does the SER do?

  Store and transport lipids and carbohydrates
• What organelles have double membranes?

  Nucleus, Mitochondria, Chloroplasts
• What is the stroma made from and used for?


  Fluid-filled matrix, which also contains starch grains

  Secondary photosynthesis takes place here.
• What is a thylakoids' structure like?

  Disc-like and contains chlorophyll
• What happens at the thylakoids?

  Photosynthesis
• What is a grana?

  Stacks of thylakoids
• What are intergranal lamella?

  Tubular structures between grana
• What is the endosymbiotic theory?

  The theory that mitochonria and chloroplasts were primitive bacteria cells until a large host cell ingested them.

  This is because they both have their own DNA and make their own proteins
• What are the cell walls in algae made from?

  Cellulose or glycoproteins or both
• What are the cell walls in fungi made from?

  Chitin
• What is the structure of a cell vacuole?

  A fluid-filled sac bounded by a single membrane called the tonoplast.