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BMS 242 - Core Phys/pharm > Introduction > Flashcards

Flashcards in Introduction Deck (58)
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1

What % of the membrane is:
Lipids
Proteins
Carbohydrates

Lipids - 42%
Proteins - 55%
Carbohydrates - 3%

2

Where are Na+ the highest?

In the plasma and interstitial fluid (extracellular)

3

Where are Na+ the lowest?

Intercellular fluid

4

Where are K+ the highest?

Intercellular

5

Where are K+ the lowest?

In the plasma and interstitial fluid (extracellular)

6

Where are Cl- the highest/lowest?

Highest outside of the cell
Lowest inside

7

Where are PO4^2- the highest/lowest?

Highest inside of the cell (ATP)
Lowest outside of the cell

8

Where is HCO3- found?

What is it important for?

In the interstitial fluid, plasma and intracellular fluid

Important pH buffer

9

Which cells have higher Cl- INSIDE?

Chloride secreting cells in the upper airway epithelial cells

10

What molecules are transported across the membrane via diffusion?

Lipid soluble molecules
(O2, CO2)

11

What molecules are transported across the membrane via transport proteins?

Small molecules and ions

12

What molecules are transported across the membrane via endocytosis?

Large molecules

13

What is another name for carrier proteins?

Facilitated transport proteins

14

What are carriers driven by?

The electrochemical gradient

15

What are examples of a carrier?

Sodium glucose cotransporter
Ion channels

16

What are primary active transport proteins?

Pumps
eg. ATPases
ONLY work if ATP is present

17

What is an important feature about channels?

They are GATED

18

Which transport proteins facilitate ACTIVE transport?

PUMPS

19

Which transport proteins facilitate PASSIVE transport?

Carriers and channels

20

What is active transport?

AGAINST the electrochemical gradient

Channels DIRECTLY hydrolyse ATP to change confirmation of the protein

Requires energy through ATP hydrolysis

Substances bind on one side of the membrane and are released on the other side, as a result of conformational change

21

What is passive transport?

FOLLOWS the electrochemical gradient

Are INDIRECTLY reliant on the NA/K ATPase to set up the electrochemical gradient

So they are INDIRECTLY reliant on ATP

Secondary active transport proteins

22

When is ATPase active transport needed?

When there is NO electrochemical driving force or when need to go AGAINST the electrochemical driving force

23

What is the transport rate of ATPase active transport?

LOW turn-over

24

What is the structure of Na/K ATPase?

Tetramer:
2 alpha subunits
2 beta subunits

25

Where is Na/K ATPase found?

Ubiquitous (in nearly EVERY cell in the body)

NOT found in RBC of DOG

26

What does Na/K ATPase transport?

What does this generate?

3 Na+ OUT
2 K+ IN

Generates a net loss of 1 positive charge from the cell - generating a -ve intracellular charge

27

What does Na/K ATPase maintain?

What is this important for?

Low Na+ INSIDE the cell

Important to drive carriers and channels, which work with the electrochemical gradient

28

What is the transport of carriers (facilitated transport proteins) dependant on?

The electrochemical gradient of at least ONE of the substances being transported (usually the Na+ gradient)

29

What is the turnover of carriers?

High

30

What can happen to carriers?

Why?

They can become SATURATED

As cannot put any more channels in the membrane