Chapter 1

Question 1

What is the relationship between water and fat composition?

Answer 1

Inversely proportional
- the more body water, the less body fat
- the less body water, the more body fat

Question 2

Distribution of the total body water

Answer 2

2/3 Intra-celular
1/3 extra-celular (interstitial and plasma)

Question 3

What is electroneutrality ?

Answer 3

When each compartment has the same concentration of cations and anions

Question 4

Which are the main intra-cellular ions?

Answer 4

Potassium, Magnesium and Phosphate

Question 5

Which are the main extracellular ions?

Answer 5

Sodium, Chloride, Calcium and Bicarbonate

Question 6

What is the normal osmolarity?

Answer 6

290 mOsm/L

Question 7

If the main goal is maintaining electroneutrality. How is the concentration difference generate?

Answer 7

Energy consuming transport mechanisms

Question 8

Two examples of energy consuming transport mechanisms ?

Answer 8

1. Against electrochemical gradients (NA-K ATPase)
2. Against gradient concentration (Ca - ATPase)
   They both need energy

Question 9

In which mechanisms is important to have differences in concentration gradients? (4)

Answer 9

1. Nerve and muscle RMP
2. Action potential excitable cells
3. Muscle contraction
4. Absorption of nutrients

Question 10

What is the Gibbs-Donnan equilibrium?

Answer 10

Small distribution of anions and cations to equilibrate the charges due to the negative charge of plasma proteins

Question 11

Components of the cell membrane ?

Answer 11

Lipids and proteins

Question 12

Which are the three different kinds of lipids that are in the cell membrane?

Answer 12

1. Phospholipids
2. Cholesterol
3. Glycolipids

Question 13

What substances have low permeability due to the lipid membrane ?

Answer 13

Ions
Urea
Glucose
Aminoacids

Question 14

What substances have high permeability due to the lipid membrane?

Answer 14

Alcohol
Steroids
CO2
O2
Fatty acids

Question 15

What is the function of the proteins in the cell membrane?

Answer 15

Transporters
Enzymes
Hormone receptors
Cell-surface antigens
Ions
Water channels

Question 16

How is the composition of the cell membrane (layer)?

Answer 16

Bilares
1-Phospohorylated glycerol: hydrophilic
2-Fatty acids : hydrophobic

Question 17

What are the two different types of proteins that are in the cell membrane’

Answer 17

1. Integral proteins
2. Peripheral proteins

Question 18

Difference between the two types of proteins in the cell membrane?

Answer 18

Integral: transmembrane, communicates with IC and EC space, serve as transporting and signaling
Peripheral : Not embedded, attached by ionic interactions

Question 19

What are the two general types of transport across membranes?

Answer 19

1. Simple diffusion
2. Carrier mediated transport

Question 20

How does simple diffusion works?

Answer 20

Cross easily, lipofilic, no carrier or energy required and follows gradient

Question 21

Give an example of subtances that cross by simple diffusion ?

Answer 21

Alchohol
Steroids
CO2
O2

Question 22

How does carrier mediated transport works?

Answer 22

Won’t cross easily
Need a carriers and SOME types will require energy
Charged and large molecules

Question 23

What are the types of carrier mediated transport?

Answer 23

1. Facilitated diffusion
2. Primary active transport
3. Secondary active transport

Question 24

Which of the carrier mediated types pf transport, require energy?

Answer 24

Primary and secondary active transport

Question 25

Give an example of facilitated diffusion

Answer 25

Glucose by GLUT receptors
H2O, Na and Cl

Question 26

Example of primary active transport
Remember: they move against the concentration gradient

Answer 26

NA-K pump
CA ATPase pump
H-K pump (gastric acid)

Question 27

Example of secondary active transport

Answer 27

Two or more molecules at the time
- Na/K pump carriers Glu and K escapes