Module 3: Organelles Of The Cytoplasm/Cell

Question 1

Peroxisome

Answer 1

• Membranous sacs containing oxidase enzymes
• Detoxification
• Breaks down hydrogen peroxide (byproduct of lysosomes)

Question 2

Lysosomes

Answer 2

• Membranous sacs containing digestive enzymes
• Intracellular digestion of toxic substances and waste products
• Releases hydrogen peroxide as a byproduct

Question 3

Golgi Apparatus

Answer 3

• Stacked Flat sacks
• Receives proteins (and some lipids) from rough ER and prepares them for distribution
• Receives and distributes via vesicles

Question 4

Smooth ER

Answer 4

• Looping network of tubes continuous with the rough ER
• Involved in lipid and carb metabolism (NOT protein)
• Sarcoplasmic Reticulum (muscle) is a version of smooth ER

Question 5

Rough ER

Answer 5

• Series of membranes/tubes
• Processes proteins made by the ribosomes
• Sends proteins to the golgi apparatus

Question 6

Ribosomes

Answer 6

• Site of protein synthesis
• Free floating in cytosol
• Some attached to the Rough ER membrane

Question 7

Mitochondria

Answer 7

• Provides energy
• # of mitochondria reflect the energy needs of the cell
• Has a double membrane -> Selectively permeable

Question 8

Nucleus

Answer 8

• Essentially runs the
  cell
• Contains genetic
  material
• Some cells have none
  (“anucleate” - mature
  red blood cells) or several
  (“multi-nucleate” -
  skeletal muscle)

Question 9

Nuclear Envelope

Answer 9

• Double membrane
  separated by fluid-filled space
• Outer: continuous
  with RER and has
  ribosomes
• Inner: maintains
  nucleus shape and
  organizes DNA
• Regulates entry/exit
  of substrates

Question 10

Nucleoli

Answer 10

• One or two in each
  nucleus
• Form ribosome
  components (these
  leave nucleus then
  assemble fully)

Question 11

Chromatin

Answer 11

• Composed of DNA
  and histone proteins
  (which organize DNA)
• Becomes condensed
  and active for cell
  division

Question 12

Microfilaments

Answer 12

-Smallest
- Thin strand made of spherical protein subunits called ACTIN
- Stretches so it resists compression
- Spider web shape

Question 13

Intermediate Filaments

Answer 13

• Tough insoluble protein fibers
• Woven semi-thick ropes composed of tetramer fibrils (4)
• Cell looks like a ball of hair
• Resists tensile force/tension

Question 14

Microtubules

Answer 14

• Biggest
• Hollow tubes of spherical protein subunits called TUBULIN
• Holds organelles in place

Question 15

Centrosome

Answer 15

• Composed of two
  centrioles &
  microtubules
• Generates
  microtubules and
  mitotic spindle
  (during cell division)