Exam 1 – Lecture 2: Dr. Langston

Question 1

What is biotransport?

Answer 1

Movement of substance through the cell membrane

Question 2

What does the cell membrane regulate?

Answer 2

The transfer of substances into and out of the cell

Question 3

What are mechanisms of biotransport?

Answer 3

Passive diffusion
Facilitated diffusion
Active transport
Endocytosis (pinocytosis/phagocytosis)

Question 4

What is the cell membrane structure?

Answer 4

Fluid mosaic model of the cell membrane

Phospholipid is the basic layer

Question 5

What do proteins provide to a membrane?

Answer 5

Specificity

Question 6

What are proteins defined by?

Answer 6

Mode of association with the lipid bilayer

Question 7

What are some integral proteins?

Answer 7

Channels
Pores
Carriers
Enzymes

Question 8

What are some peripheral proteins?

Answer 8

Enzymes

Intracellular signal mediators

Question 9

What do integral proteins do?

Answer 9

Pass all the way through the membrane

Question 10

What do peripheral proteins do?

Answer 10

They are embedded into one of the 2 sided, but do not go all the way through

Question 11

What does the “glyco” prefix refer to?

Answer 11

Sugar/carbohydrate

Question 12

What makes up the majority of integral proteins?

Answer 12

Glycoproteins

Question 13

What are 2 types of glycoproteins?

Answer 13

Proteoglycans

Glycocalyx

Question 14

What is a glycocalyx?

Answer 14

A glycoprotein covering that surrounds the cell membranes

Question 15

What are GAGs (glycosaminoglycan) designed to do?

Answer 15

Supplement the glycoproteins, usually for joint health

Question 16

What amount of cholesterol is present in the membranes?

Answer 16

Varying amounts

Question 17

What does cholesterol do?

Answer 17

Decreases membrane fluidity and permeability

Increases membrane flexibility and stability

Question 18

What is the head of the phospholipid like?

Answer 18

Polar and hydrophilic

Question 19

What is the tail of the phospholipid like?

Answer 19

Nonpolar and hydrophobic

Question 20

What is the rate of diffusion governed by?

Answer 20

Fick’s Law of Diffusion

Question 21

In Fick’s Law of Diffusion, the characteristics of what 2 things are used to determine the rate of diffusion?

Answer 21

Membrane and solute

Question 22

What are the characteristics of the membrane used for Fick’s Law of Diffusion?

Answer 22

Surface area
Membrane thickness
Diffusion

Question 23

What are the characteristics of solute used for Fick’s Law of Diffusion?

Answer 23

Oil-water partition

Concentration difference for solute

Question 24

For a solute to passively diffuse through a membrane, what must it be like?

Answer 24

Lipid soluble
Unionized
Small

Question 25

What is the membrane a major route of cell entry for?

Answer 25

Many drugs

Question 26

What can pass easily through the membrane?

Answer 26

Oxygen, CO2, nitrogen

Question 27

If an ion has a charge, how will it cross the membrane?

Answer 27

Not very well. It must be relatively neutral to cross

Question 28

Will bound proteins cross the membrane?

Answer 28

No, only unbound

Question 29

How does water primarily enter the cell?

Answer 29

By pores that are channel proteins

Question 30

What do facilitated diffusion gated protein channels play a role in?

Answer 30

Ion and neurotransmitter passage

Question 31

Which is more negative, the inside or outside of the cell?

Answer 31

Inside

Question 32

What are the 2 types of gated channels?

Answer 32

Voltage-gated | Ligand-gated

Question 33

What is depolarization?

Answer 33

The electrical impulse coming down the nerve

Question 34

What is a ligand?

Answer 34

Any substance that binds to a receptor to create a response

Question 35

How does muscle contract?

Answer 35

Via ligand-gated channels

Question 36

What is facilitated diffusion?

Answer 36

A type of passive diffusion that utilizes a carrier protein for the solute to cross the membrane

Question 37

Does facilitated diffusion use energy?

Answer 37

No

Question 38

What can facilitated diffusion become unlike passive diffusion?

Answer 38

Saturated

Question 39

What does active transport do?

Answer 39

Uses a carrier protein to move solute against a concentration gradient Requires energy

Question 40

What are the 2 types of active transport?

Answer 40

Primary and secondary

Question 41

What is primary active transport?

Answer 41

Uses a direct expenditure of ATP as the energy source

Question 42

What is secondary active transport?

Answer 42

Uses the energy derived secondarily from energy that has been stored in the form of ionic concentration differences of secondary molecular or ionic substances between the two sides of a cell membrane, created originally by primary active transport

Question 43

What is a very important type of active transport?

Answer 43

Na/K transport

Question 44

What does the Na/K ATPase pump do?

Answer 44

Maintains the sodium and potassium concentration differences across the cell membrane Controls cell volume Establishes a negative electrical voltage in the cell

Question 45

How much of the cell's energy requirement is devoted to pumping sodium out an potassium in the cell?

Answer 45

60-70%

Question 46

What are 2 other primary active transport systems that are important?

Answer 46

Calcium ATPase pump | H+-K+ ATPase

Question 47

What is the calcium ATPase involved in?

Answer 47

Muscle contraction

Question 48

What are the 2 types of secondary active transport?

Answer 48

``` Co-transport (symport) Counter transport (antiport) ```

Question 49

What are 2 types of symport systems?

Answer 49

Sodium-glucose co-transport | Sodium-amino acid co-transport

Question 50

What are 2 types of antiport systems?

Answer 50

Sodium-calcium counter-transport | Sodium-hydrogen counter transport

Question 51

What does symport mean?

Answer 51

Both molecules move the same way

Question 52

What does antiport mean?

Answer 52

One ion moves one way and the other moves in the other direction

Question 53

What is pinocytosis?

Answer 53

Cell drinking | Used to move very large molecules in a solution inside the cell

Question 54

What is pinocytosis used with?

Answer 54

Very large, charged molecules that have properties that won't typically let it diffuse

Question 55

What is phagocytosis?

Answer 55

Cell eating | Used to move large particles instead of molecules

Question 56

What is the rule of thumb for water and sodium?

Answer 56

Water follows sodium

Question 57

What does active transport through cellular sheets often involve?

Answer 57

A combination of biotransport processes

Question 58

How can you combat dehydration?

Answer 58

Sodium and a little bit of glucose cause water absorption

Question 59

How can you replenish fluids?

Answer 59

Oral electrolyte solutions