40A - Lecture - Chapter #3

Question 0

Cytoplasm

Answer 0

Aka cytosol
Intracellular fluid + organelles
Water + anything dissolved

Question 1

3 principle parts of cell

Answer 1

Nucleus
Cytoplasm
Plasma membrane

Question 2

Plasma membrane (cell membrane)

Answer 2

“Fluid mosaic membrane”, membrane between outside and inside

3 main components: phospholipid, cholesterol, glycolipid

Question 3

Phospholipid (in membrane)

Answer 3

Most abundant

Only hydrophobic substances and water can directly cross

Question 4

Cholesterol

Answer 4

Orientated in a particular way, alcohol wants to be near water.
Gives str to membrane but less fluidity

Question 5

Glycolipid (sugar lipid)

Answer 5

Wants to be near water, sugar will go towards ECF, will sometimes bind to protein

Question 6

Proteins in plasma membrane

Answer 6

Integral protein: transport ions
Glycoproteins: sugar transport
Peripheral protein: does not fully go through PM

Question 7

Ion channel

Answer 7

Integral protein

Allows specific ions to move through water-filled pores. No ATP, uses concentration gradient

Question 8

Carrier (transport)

Answer 8

Integral protein
Carry of transport polar molecules (ex: amino acid, glucose) changes their shape to movie
Ex: urea, breaks down a.a

Question 9

Receptor

Answer 9

Integral protein
Receive info, recognize molecule specifically can be found anywhere
Ligand is a general term and it binds to receptor. Once blinded it will bring unit into cell
Ex: ligand is insulin, receptor is insulin receptor

Question 10

Enzyme

Answer 10

Integral and peripheral protein

Catalyze reaction inside or outside cell

Question 11

Permeable

Answer 11

Can go directly through bilayer
Lipid soluble = hydrophobic or nonpolar
Nonpolar - uncharged: H2O, steroids, urea
“Small” substances

Question 12

Impermeable

Answer 12

Cannot directly go across bilayer
Ex: ions need channels
Uncharged and polar molecules
Ex: glucose (needs carrier or transporter)

Question 13

Gradient

Answer 13

Difference created along membrane; difference outside of cell membrane near ECF compared to inside

Question 14

Components of electrochemical gradient

Answer 14

Electrical and concentration

Question 15

Electrical gradient

Answer 15

Charge difference in PM
Either at rest or action potential
When there’s action charges flip

Question 16

“At rest”

Answer 16

Spends energy to make gradient
ECF = +
ICF = -

Question 17

Action potential

Answer 17

ECF = - 
ICF = +

Question 18

Concentration gradient

Answer 18

Chemical difference in PM
Ex: O2 goes inside cell, CO2 goes outside cell
Ex: Na+ (high in ECF), K+ (high in ICF)

Question 19

Active process

Answer 19

Goes against gradient, uses ATP

Ex: Na, K ATPase pump

Question 20

Na, K ATPase pump

Answer 20

Enzyme for molecule
Wants K high in ICF, Na high in ECF
Makes an electrochemical gradient
Keeps shape of cell
Contains primary and secondary pumps

Question 21

Primary

Answer 21

Uses 40% of energy to run pumps

1. 3 Na from cytosol bind side surface of pump (ADP + P + E)
2. Na biding triggers ATP to bind on pump and splits ATP to ADP and P. Energy from splitting causes protein to change shape
3. 2 K from outside land in pump caused P to be released
4. Release of P causes pump to return to original shape. Moves K from pump

Question 22

Secondary

Answer 22

Does not work unless primary pumps set up gradient
Does not use ATP, uses energy stored in an ionic concentration gradient
Contains antiporters and symporters
Na does not go against gradient

Question 23

Antiporters

Answer 23

Carry two different sub at different directions

Question 24

Symporter

Answer 24

Carry two substances at the same direction