Science 2.1 Cell structure, function, and organization

Question 1

Centrosome

Answer 1

A region of cytoplasm that contains a pair of centrioles oriented at right angles to one another
Function: Essential for movement of chromosomes during dell division organization of microtubules in cytoskeleton.

Question 2

Centriole

Answer 2

A cylindrical intracellular organelle composed of nine groups of microtubules, three in each group . Functions in mitosis or meiosis by organizing the microtubules of spindle apparatus
Function: Essential for movement of chromosomes during dell division organization of microtubules in cytoskeleton.

Question 3

Cytoskeleton

Answer 3

Proteins organized in fine filaments or slender tubes

Function: Strength and support; movement of cellular structures and materials

Question 4

Plasma Membrane

Answer 4

Lipid bilayer containing phospholipids, steroids, proteins, and carbohydrates
Function: Isolation; protection; sensitivity, support; controls entry and exit of materials

Question 5

Microvilli

Answer 5

Extensions of the plasma membrane containing microfilaments.

Function: Increase surface area to facilitate absorption of extracellular materials

Question 6

Cilia

Answer 6

Lone extensions of the plasma membrane containing microtubules. There are two types: Primary and motile.
Function: A primary cilium acts as a sensor. Motile cilia move materials over cell surfaces.

Question 7

Proteasomes

Answer 7

Hollow cylinders of proteolytic enzymes with regulatory proteins at their ends
Function: Breakdown and recycling of damaged or abnormal intracellular proteins

Question 8

Ribosomes

Answer 8

RNA + proteins; fixed ribosomes bound to rough endoplasmic reticulum; free ribosomes scattered in cytoplasm.
Function: Protein synthesis

Question 9

Peroxisomes

Answer 9

Vesicles containing degradative enzymes
Functions:
Catabolism of fats and other organic compounds; neutralization of toxic compounds generated in the process

Question 10

Lysosomes

Answer 10

Vesicles containing digesting enzymes
Function:
Intracellular removal of damaged organelles or pathogens

Question 11

Golgi apparatus

Answer 11

Stacks of flattened membranes (cisternae) containing chambers
Functions:
Storage, alteration, and packaging of secretory products and lysosomal enzymes

Question 12

Mitochondria

Answer 12

Double membrane, with inner membrane folds (cristae) enclosing important metabolic enzymes
Function:
Produce 95% of the ATP required by the cell

Question 13

Endoplasmic Reticulum (ER)

Answer 13

Network of membranous channels extending throughout the cytoplasm
Functions: Synthesis of secretory products; intracellular storage and transport; detoxification of drugs or toxins.
Rough ER modifies and packages newly synthesized proteins. Smooth ER synthesizes lipids and carbohydrates

Question 14

Nucleus

Answer 14

Double phospholipid membrane (four layers)