Week 1: Homeostasis and Membrane Transport Mechanisms; Part of AP

Question 1

Glucose transporters (GLUT transporters) employ which of the following kinds of transport? Diffusion Primary active transport Secondary active transport Facilitated diffusion

Answer 1

Facilitated diffusion

Question 2

The sodium-potassium pump is an example of which of the following: Diffusion Primary active transport Secondary active transport Facilitated diffusion

Answer 2

Primary active transport

Question 3

The sodium-calcium pump is an example of which of the following? Diffusion Primary active transport Secondary active transport Facilitated diffusion

Answer 3

Secondary active transport

Question 4

Which of the following transport mechanisms requires energy other than kinetic energy? Osmosis Diffusion Active transport Facilitated diffusion

Answer 4

Active transport

Question 5

Of the following ions, which is the most concentrated in the extracellular matrix? Sodium Potassium Chloride Calcium

Answer 5

Sodium

Question 6

The sodium glucose pump is an example of which of the following kinds of transport? Diffusion Primary active transport Secondary active transport Facilitated diffusion

Answer 6

Secondary active transport

Question 7

Define Osmosis

Answer 7

The movement of solvent (water) from high to low concentration through a semipermeable membrane

Question 8

Van’t Hoff’s law

Answer 8

Osmotic pressure depends on the concentration of osmotically active particles

Question 9

Osmotic Pressure Equation

Answer 9

Question 10

What are the energy independent transport types? (3)

Answer 10

Osmosis, Diffusion, and Facilitated Diffusion

Question 11

Which type of tranporters require channel proteins?

Answer 11

Gated and Non-gated;

Gated = ligand gated, voltage gated

Non-gated = aquaporins, ion channels

Question 12

Another name for antiporters:

Answer 12

Countertransporters and exchangers

Question 13

What is diffusion dependent upon?

Answer 13

The KE of particles, NOT the external energy source (metabolic energy)

Question 14

What factors affect the rate of diffusion? (3)

Answer 14

1. Concentration across the membrane
2. Membrane electric potential (Nerst equation)
3. Pressure difference

Question 15

What 3 factors change membrane permeability?

Answer 15

1. oil/water partition coefficient
2. membrane thickness
3. solute size

Question 16

Which transport mechanism is the only one that does not require a carrier-mediated protein?

Answer 16

Simple diffusion

Question 17

Characteristics of facilitated diffusion?

Answer 17

1. Requires uniporter carrier proteins (carrier proteins give molecules their specificity i.e. D- and L-glucose
2. Has a V_max
3. Used by glucose and amino acids

Question 18

Question 19

Non-gated Channel examples

Answer 19

1. Aquaporins
2. K⁺ channels
3. Na⁺ channels

Question 20

How is energy for secondary transport established?

Answer 20

Through the concentration differences that occur from primary active transport

During this type of transport, one solute is moving down it’s gradient while the other is moved against

Na⁺ is usually the ion involved in secondary active transport

Question 21

If Na⁺ moves down its electrochemical gradient, why is this referred to as secondary active transport?

Answer 21

ATP is required in order for the Na⁺ gradient to occur so that it can move down it’s gradient

Question 22

Na⁺/Ca²⁺ antiporters move 3Na⁺ per Ca²⁺, why does it take 3 Na⁺ ions to move 1 Ca²⁺?

Answer 22

Ca²⁺ has a greater electrochemical gradient, is a larger cation, therefore Na⁺ must overcome this size and charge difference

Question 23

What are some characterstics of the Na+/K+ pump? (3)

Answer 23

Both are moved against their [gradient]

Conformation change occurs to pass ions through

Pump can be used reversily to generate ATP

Question 24

What type of transporter is this is a few characteristics?

Answer 24

Secondary active transporter; cotransporter

Na⁺ gradient is created via primary active transport and the greater [Na⁺] allows for passive movement by binding and crossing, which in turn allows glucose to pass through and both substances are transported together

Question 25

Na⁺ gradient caused during primary active transport causes what secondary active transporter mechanisms?

Answer 25

Na⁺/Glucose cotransporter

Na⁺/H⁺ counter transporter

Na⁺/Ca²⁺ counter transporter

Question 26

Answer 26

Question 27

What are the assumptions for the Nernst equation? (3)

Answer 27

1. The equation can be used only for one ion at a time.
2. The membrane must be completely permeable to that ion.
3. That ion must be at equilibrium

Question 28

What are the 3 characteristics of an action potential?

Answer 28

1. self-propagated 2. all-or-none 3. non-decremental (doesn’t decrease in strength)

Question 29

Describe the status of Na+ and K+ gates during an action potential (inactivation/activation and potential values)

Answer 29

Question 30

Locations of simple squamous epithelium

Answer 30

• lumina lining of ducts, vessels and other tubular structures
• walls of alveoli, Bowman’s capsules and inner surfaces of membranous labyrinth and tympanic membrane

Question 31

Locations of simple cuboidal epithelium

Answer 31

• surface of ovary
• pigmented epithelium of retina
• kidney tubules
• glands and ducts
• terminal bronchioles
• choroid plexus
• anterior capsule of lens of eye

Question 32

Loctations of simple columnar epithelium

Answer 32

• Ciliated: upper respiratory tract, uterine tubes, uterus, paranasal sinuses, central canal of spinal cord
• Non-ciliated: digestive tract such as the cardia of the stomach, gall bladder, parts of excretory ducts of glands

Question 33

Locations of stratified squamous epithelium (heavily keratinized vs. lightly keratinized)

Answer 33

1. Heavily - epidermis (with CT papillae) and cornea (w/out CT papillae)
2. Lightly or Non-Keratinized - esophagus, vagina, lining of mouth, tongue, and part of epiglottis

Question 34

Locations of stratigied cuboidal epithelium

Answer 34

1. seldom found; small areas of anal mucosa, large excretoy ducts of some glands, part of male urethra

Question 35

Locations of stratified columnar epithelium

Answer 35

1. seldom found; ducts of adult sweat glands, fornix of the conjunctiva of the eye, parts of male reproductive/urinary tract, pharynx, epiglottis

Question 36

Locations of pseudostratified columnar epithelium

Answer 36

1. Trachea

Question 37

Location of pseudostratified epithelium

Answer 37

Epididymis with stereocilia (branched microvilli)

Question 38

Locations of transitional epithelium

Answer 38

1. urinary system = urothelium

Question 39

Functions of epithelial tissues (2)

Answer 39

1. Covering and lining
2. Glandular secretions

Question 40

Where are leaky barriers of epithelial tissues found?

Answer 40

1. gallbladder lining
2. proximal convoluted tubule