Cell Membrane

Question 1

cell

Answer 1

the smallest unit of life

Question 2

functions of life

Answer 2

1. growth
2. metabolism
3. development
4. reproduction
5. adaption
6. respiration
7. homeostasis

Question 3

prokaryotic cells

Answer 3

the first cells; have NO nucleaus

Question 4

eukaryotic cells

Answer 4

have a distinct nucleus and are found in all multi-cellular organisms today

Question 5

size limitations of cells

Answer 5

restricted to 10-30 µm in diameter in animals

Question 6

small cells

Answer 6

• have a proportionally larget surface area which allows for more nutrients to be absorbed
• have better control over the activity in the cell by a single nucleus

Question 7

large cells

Answer 7

• have a relatively small surface area
• may have many nuclei

Question 8

basic parts of the cell

Answer 8

1. cell membrane (plasmalemma)
2. cytoplasm
3. nucleous

Question 9

cell membrane

Answer 9

• flexible, elastic barrier between inner cytoplasm and the outside environment
• consists primarly of protein and phospholipids

Question 10

cell membrane functions

Answer 10

• boundary between extracellular and intracellular compartments
• controls passage of substances into and out of the cell
• maintains membrane receptors for attachment of small molecules

Question 11

the cell membrane is composed of

Answer 11

1. membrane structure
2. caveolae
3. flagella/cilla

Question 12

cell membrane structure

Answer 12

very thin and composed of:

lipid bilayer

fluid mosaic

cholestrerol molecules

Question 13

lipid bilayer

Answer 13

composed of phospholipids:

hydrophilic lipids and hydrophobic lipids

Question 14

hydropholic lipids

Answer 14

face the cell surface to absorb or mix with water

Question 15

hydrophobic lipids

Answer 15

face the inside of a cell to avoid water

Question 16

fluid mosaic

Answer 16

proteins suspended in the bilayer which move easily through the membrane causing continual change in the mosaic of lipids and proteins

Question 17

cholesteral molecules

Answer 17

stabelizes the membrane of a cell and increases permeability to water

Question 18

lipid soluable materials

Answer 18

can pass though the membrane

such as oxygen and carbon dioxide

Question 19

water soluable molecules

Answer 19

do not readily pass through

ie - amino acids, sugars, and proteins

Question 20

caveolae

Answer 20

• small 50 nanometer folds in the plasma membrane
• function is to transport materials into the cell and transport materials to another part of the cell
• produced only from rafts in the plasma membrane that contain protein caveolin

Question 21

flagella and cilla

Answer 21

• energetic, motile “hairs” that extend into extracellular space
• extensions of the plasma membrane
• originate from a pair of centrioles called basal bodies located under the plasma membrane

Question 22

proteins in the cell membrane

Answer 22

globular proteins that are responsible for membrane’s special functions

Question 23

integral proteins

Answer 23

found within the lipid bilayer and include channel proteins and pores

Question 24

peripheral proteins

Answer 24

• bound to the inside or outside surfaces of the membrane
• behave as catalysts for cellular activity
• internal peripheral proteins are limited in their movements

Question 25

glycocalyx

Answer 25

• “sugar cotating” covering surface of cells
• involved in cell to cell adhesion
• interact with extracellular molecules to cause membrane changes

Question 26

rafts in the fluid mosaic

Answer 26

• areas of densly packed phospholipids, proteins, and cholesteral
• form plaque like structures within the cell membrane
• initiate cell division and vesicle formation

Question 27

cytokinesis

Answer 27

physical process of cell division, which divides the cytoplasm of a parental cell into two daughter cells