The Cell Membrane

Question 1

cell membrane?

Answer 1

extremely pliable structure composed of back-to-back phospholipds (a bilayer)
- phosphate heads (hydrophillic) and 2 fatty accid tails (hydrophobic)

Question 2

what does amphipathic mean?

Answer 2

molecule that contains hydrophilic and hydrophobic regions

Question 3

integral protein

Answer 3

protein embedded in membrane

Question 4

channel protein

Answer 4

inegral protein that allows specific materials (like ions) to pass in or out of cell

Question 5

receptor

Answer 5

recognition protein that can selectively bind a specific molecule outside the cell

Question 6

ligand

Answer 6

molecule that binds to and activates a receptor

Question 7

glycoprotein

Answer 7

protein that has carbohydrate molecules attatched that extend into the EC matrix

Question 8

glycocalyx

Answer 8

• fuzzy looking coating around the cell formed by glycoproteins and other carbs attatched onto the cell wall
• roles: has molecules that allow cell to bind to another cell, receptors for hormones, enzymes to break down nutrients

Question 9

peripheral proteins

Answer 9

inner or outer surface of lipid bilayer but can attatch to surface of entegral protein
- perform function for cell like: act as digestive enzymes

Question 10

selective permeability

Answer 10

allows only substances meeting specific criteria to pass through unaided

Question 11

what can pass through cell mem?

Answer 11

• small nonpolar materials
• other lipids, oxygen and CO2 and alcohol

Question 12

what needs help to go through cell mem?

Answer 12

water-soluble materials
- glucose
- amino acids
- electrolytes

Question 13

polar molecules

Answer 13

• unequal amounts of electrons (singles and ready to mingle thats why theyre on the outside)
• likes water (like a polar bear)
• heads of phospholipids

Question 14

nonpolar molecules

Answer 14

• equal pairings of electrons
• tails of phospholipids

Question 15

simple diffusion

Answer 15

• passive transport
• moves with flow
• high conc to low conc
• no atp required

Question 16

facilitated diffusion

Answer 16

• passive
• high to low conc
• with help of transport proteins

Question 18

ATP

Answer 18

adenine triphosphate

Question 19

endocytosis

Answer 19

• in
  vesicles tak into the cell
• phagocytosis: large particles are ingested: surround and eat
• receptor-mediated endyocytosis: process that allows cells to absorb substances from outside the cell USING cell receptors
• pinocytosis: ECF and solutes are taken into the cell via small vesicles

Question 20

Exocytosis

Answer 20

• moving outward/ exit
• gets rid of waste

Question 21

concentration gradient

Answer 21

difference in concentration of substance across a space

Question 22

diffusion

Answer 22

movement of high conc to lower conc

Question 23

where does O2 typically diffuse? why?

Answer 23

into cells bc its more conc outside of them

Question 24

where does CO2 typically diffuse?

Answer 24

out of cells bc its more conc outside

Question 25

faciliated diffusion

Answer 25

diffusion process used for substances that cant cross lipid bilayer due to their size, charge or polarity

Question 26

osmosis

Answer 26

diffusion of water through a semipermeable membrane

Question 27

isotonic

Answer 27

two solutions that have same conc of solutes (equal tension)

Question 28

hypertonic

Answer 28

higher conc of solutes than other solution - cell shrivesl as ater leaves cell via osmosis

Question 29

hypotonic

Answer 29

solution that has lower conc of solutes than other solution - will take on too much water and swell at risk of bursting

Question 30

types of active transport

Answer 30

- require pumps - require atp

Question 31

what is the Na/K pump

Answer 31

- found in membranes of many types of cells - abundant in nerve cells

Question 32

electrical gradient

Answer 32

difference in electrical charge across a space - inside of negatively-charged relative to the outside - maintained bv the na/k pumps move 3 + out and 2K+ in for each ATP molecule used

Question 33

symporters

Answer 33

secondary active transporters that move 2 substances in the same direction

Question 34

antiporters

Answer 34

secondary active transport systems that transport substances in opposite directions

Question 38

exocytosis

Answer 38

- taking 'out of the cell' - process of cell exporting material using vesicular transport -