Unit 2 Bio

• What are the two main types of cells?

  Eukaryotic and prokaryotic cells
• What type of cell are animal and plant cells?

  Eukaryotic cells
• What does a eukaryotic cell have that a prokaryotic cell does not have?

  Membrane-bound organelles
• What is a cell's ultrastructure?

  The detailed structure of a cell
• What are the main structures found in most eukaryotic cells?

  Nucleus, mitochondria, Golgi apparatus
• What is the function of the nucleus?

  Retains genetic material of the cell
• What type of DNA is found in the nucleus?

  Protein-bound, linear DNA
• What molecules are made inside the nucleus?

  mRNA, tRNA, rRNA
• What is the structure and function of the nucleolus?

  Dark, dense region producing ribosomes
• In a nucleus, can there be more than one nucleolus?

  Yes
• What is the structure of the nuclear envelope?

  A double membrane with pores
• What is the function of the nuclear envelope?

  Separates the nucleus from the cell
• What is the structure of the rough endoplasmic reticulum (RER)?

  Fluid-filled membranes studded with ribosomes
• What is the function of the rough endoplasmic reticulum (RER)?

  Synthesis and transport of proteins
• What is the structure of the Golgi apparatus?

  A stack of flattened membrane-bound sacs
• What is the function of the Golgi apparatus?

  Modifies and packages proteins and lipids
• What molecules are ribosomes made out of?

  rRNA and proteins
• What is the structure of ribosomes?

  Two subunits, large and small
• What size of ribosome is found in eukaryotic cells?

  80S
• What is the function of ribosomes?

  Protein synthesis
• What is the name of the model which shows the structure of the cell membrane?

  Fluid mosaic model
• What molecules make up the fluid mosaic model of the cell membrane?

  Phospholipid bilayer, cholesterol, proteins
• What is the role of the phospholipid bilayer in the plasma membrane?

  Creates a waterproof barrier
• How are proteins embedded in the plasma membrane?

  On one surface or spanning the bilayer
• What is the role of proteins embedded on the surface of a plasma membrane?

  Mechanical support and receptors
• What is the role of proteins that span the width of the plasma membrane?

  Form channels and transport substances
• How does cholesterol interact with water?

  It is very hydrophobic
• What is the role of cholesterol in the membrane?

  Reduces membrane fluidity at high temperatures
• What does cholesterol do to other molecules in the membrane?

  Holds phospholipids tightly together
• Which structures are only found in plant cells?

  Chloroplasts, cell wall, cell vacuole
• What is the structure of chloroplasts?

  Double membrane bound with thylakoid discs
• What is the function of chloroplasts?

  Site of photosynthesis
• From what type of cell is a chloroplast descended?

  Prokaryotic cell
• What structures within the chloroplast show it is descended from a prokaryotic cell?

  Circular DNA and 70S ribosomes
• What is the structure of the vacuole?

  Fluid-filled membrane sac
• What is the structure and function of the vacuole?

  Contains salts, sugars, amino acids, waste
• What is the function of a plant's vacuole?

  Provides structure and temporary food store
• What cell structure is found in some prokaryotes?

  Cell wall
• What molecule makes up a plant cell wall?

  Cellulose
• What type of molecule is cellulose?

  Polysaccharide