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Flashcards in Using Molecules to Build a Barrier Deck (36)
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1
Q

functional groups

A

(1) amino - NH2
(2) carboxyl - CO2H
(3) carbonyl - CO or COH
(4) hydroxyl - OH
(5) phosphate - PO4
(6) sulfhydryl - SH

2
Q

cell membrane

A

surrounds cell

  • regulates molecules/ions travelling btwn inner cell & environment
  • protects cell
  • thin, flexible

(aka plasma membrane)

“life’s defining barrier “

3
Q

atom

A

smallest particle that retains its ID during chem change

- building blocks of matter

4
Q

molecule

A

result of 2+ atoms bonded juntos by IM forces

- chem formula

5
Q

covalent bond

A

sharing e-

  • nonmetal & nonmetal
  • same
  • polar or nonpolar covalent bonds
  • essential for making life stable

SAME

6
Q

ionic bond

A

e- completely transfer from 1 atom to another

  • donate & accept
  • metal & nonmetal
  • 1 (-) atom, 1 (+) atom

DIFF

7
Q

hydrocarbon

A

molecule containing only C & H

  • nonpolar
  • hydrophobic
  • related to permeability
8
Q

types of lipids

A

(1) steroid
(2) phospholipid
(3) fat (triacylglycerols or triglycerols)
(4) oils
(5) waxes

9
Q

steroid

A

type of lipid
component of plasma membrane in orgs
- amphipathic

4 bulky rings + (distinguished) R group

(ie) cholesterol

10
Q

phospholipid

A

type of lipid

  • (Bacteria & Eukarya) composed of fatty acids
  • (Archaea) found w/ iosprenoid chains
  • amphipathic

glycerol + charged R group + 2 fatty acids

11
Q

fat (triacylglycerols or triglycerols)

A

type of lipid

  • nonpolar
  • responsible for energy storage
  • may be saturated or unsaturated

glycerol + 3 fatty acids

12
Q

lipid

A

organic substance

  • no dissolve in H2O
  • dissolves in polar organic solvents
13
Q

amphipathic

A

compounds that contain hydrophilic & hydrophobic elements

- responsible for plasma membrane

14
Q

membrane permeability

A

tendency to allow a given substance to pass through

15
Q

properties of substance that can cross lipid bilayer

A

(1) small & nonpolar molecules
(2) very small & uncharged, yet polar, molecules

(ie) O2 & H2O

16
Q

properties of substance that cannot cross a lipid bilayer

A

(1) large & uncharged substance

(2) ions, unless helped - charged compounds & large polar molecules dissolve in H2O

17
Q

hydrophilic

A

“water loving”

substances that interact w/ H2O

18
Q

hydrophobic

A

“water fearing”
substances that ≠ interact w/ H2O
interact w/ each other instead

19
Q

lipid bilayer

A

basic strucutural element of all cellular membranes

  • two sheets of phospholipid layers align
  • hydrophobic tails oriented toward inside
  • hydrophilic heads oriented toward outside
  • selectively permeable (small, nonpolar molecules)
20
Q

cell

A

highly organized compartment

  • contains plasma membrane & conc. chemicals (aq)
  • basic unit of matter
  • anything smaller than cell ≠ living
21
Q

atomic #

A

protons

22
Q

mass #

A

protons + # neutrons

23
Q

most common elements in orgs

A

(1) hydrogen - H
(2) carbon - C
(3) nitrogen - N
(4) oxygen - O
(5) sodium - Na
(6) magnesium - Mg
(7) phosphorus - P
(8) sulfur - S
(9) chlorine - Cl

H C N O Na Mg P S Cl

24
Q

polar covalent bond

A

e- ≠ shared equally

25
Q

nonpolar covalent bond

A

e- shared equally

26
Q

organic

A

compound containing C-H

  • C bonds w/ H N O S Mg S F or Cl
  • made by living orgs
27
Q

lipid properties

A

(1) largely nonpolar
(2) hydrophobic
(3) not all polymers
(4) fluidity depends on “packing” of lipid molecules

28
Q

lipid fcns

A

(1) energy storage
(2) insulation
(3) cell membrane
(4) hormones - testosterone, estrogen, steroids, etc.

29
Q

saturated

A

lipids w/ all single bonds
- high melting points

C-C

straight

30
Q

unsaturated

A

lipids w/ @ least 1 double bond + single bonds

C=C

bent/kinked

31
Q

micelle

A

tiny droplets

  • form circle
  • hydrophilic heads turned outward
  • hydrophobic tails turned inward
32
Q

variables of permeability

A

(1) saturation
(2) hydrocarbon chain length
(3) temp
(4) cholesterol

33
Q

saturation (permeability)

A

↑ saturation, ↑ permeability

  • saturated = less space, stronger van der Waals interactions
  • unsaturated allows more material to pass
34
Q

hydrocarbon chain length (permeability)

A

↑ chain length, ↓ permeability

  • denser membrane
  • (small tail) interior < tightly held juntos
35
Q

cholesterol (permeability)

A

↑ cholesterol, ↓ permeability

  • bulky steroid rings
  • cholesterol fill gaps in hydrophobic section of membrane
36
Q

temperature (permeability)

A

↑ T, ↑ permeability

  • room T = fluid physical state of phospholipids
  • ↓ T, hydrophobic tails pack mas juntos
  • very low T, lipid bilayers solidify