Methods of Transport

Question 1

Passive transport

Answer 1

Movement of substances across a membrane without using energy

Question 2

Diffusion

Answer 2

Movement of solutes within a cell from high to low concentration

Question 3

Molecular movement

Answer 3

Always happening when a substance is above absolute zero

Question 4

The drive behind diffusion

Answer 4

Entropy

Question 5

Entropy

Answer 5

One region is more concentrated on one side of the membrane, has localized energy

Question 6

Entropy energy

Answer 6

Entropy increases as the energy speeds until the concentrations are equal (highest)

Question 7

Rate of diffusion

Answer 7

Dependent on concentration difference, a big difference leads to fast diffusion, and a slow difference leads to slower diffusion

Question 8

Simple diffusion

Answer 8

Movement of molecules across a concentration gradient without transporters

Question 9

Rate of simple diffusion

Answer 9

Depends on molecular size and lipid soluability

Question 10

Molecules that can pass through simple diffusion

Answer 10

Nonpolar molecules, steriod hormones, amphipatic drugs and some uncharged polar molecules

Question 11

Molecules that can’t pass through simple diffusion

Answer 11

Charged molecules such as Cl-. Na+ PO43-

Question 12

Facilitated diffusion

Answer 12

Diffusion with the aid of a transporter, used by a polar and charged molecules

Question 13

Facilitated diffusion uses

Answer 13

Channel and carrier proteins

Question 14

Channel proteins

Answer 14

Provide a hydrophilic pathway in the membrane shielding the hydrophobic core, allowing molecules to pass. There are specific channels for specific molecules

Question 15

Water diffusion

Answer 15

Executed by aquaporins

Question 16

Aquaporins

Answer 16

Transport proteins in diverse organisms. Narrow and allows a billion molecules per second.

Question 17

Aquaporins preventing ions technique

Answer 17

Has a positive core which deflects positive ions from entering

Question 18

Gated channels

Answer 18

Can open, close and in between. Important for ions including Na+, K+, Ca+, Cl-

Question 19

How do gated channels open and close

Answer 19

The can use voltage, which physically alters the proteins shape

Question 20

Gated channels example

Answer 20

Nerve conduction (gated voltage), and CRFT in cystic fibrosis

Question 21

Carrier proteins

Answer 21

Binds to a specific solute and carries it though the membrane. Uniport transport, Has a high rate of substrate specificity

Question 22

Unitransport

Answer 22

Only one molecule can be taken at a time

Question 23

Substrate specificity

Answer 23

Regulating the in and out of molecules in the cell.

Question 24

Facilitated vs simple diffusion graphs

Answer 24

Facilitated is steep but reaches a plateau as all of the substrates are being used. Simple diffusion is a steady line

Question 25

Osmosis

Answer 25

The passive transport of water across a semipermeable membrane from a solution of low ion concentration to high ion concentration

Question 26

Why osmosis

Answer 26

Because the ions cannot leave so water comes in to establish the proper balance

Question 27

Types of osmosis

Answer 27

In can be simple diffusion or facilitated through aquaporins

Question 28

Hypotonic soloution

Answer 28

Lower concentration than the cells concentration. The cell swells and can burst in animal cells. Cell walls prevent bursting.

Question 29

Hypertonic solution

Answer 29

Higher concentration than the cells concentration. Water leaves the cell and it shrinks in both plant and animal cells

Question 30

In animal cells

Answer 30

Solutes go in and out of the cell, so it becomes isotonic, requires more energy because of constant ion pumping

Question 31

Active membrane transport

Answer 31

Goes against the concentration gradient. Requires energy that is often ATP.

Question 32

Active transport example

Answer 32

Concentrated sugars and amino acids inside the cell and ions outside the cell.

Question 33

3 functions of active transport

Answer 33

Uptake of essential nutrients Removal of secretory or waste Maintenance of essential intracellular concentrations

Question 34

Membrane potential

Answer 34

Electrical difference across the plasma membrane due to voltage created from active transport

Question 35

Primary active transport

Answer 35

1 protein transports and hydrolyzed ATP to use

Question 36

Secondary active transport

Answer 36

Indirectly driven by ATP, uses concentration gradients made from primary active transport to their advantage

Question 37

Primary active transport pumps

Answer 37

Transport positively charged ions essential for life

Question 38

Proton pomp (hydrogen pump)

Answer 38

Pushes H+ from the cytoplasm to the cells exterior, generates membrane potentials

Question 39

Proton pump function

Answer 39

Bonds with the third phosphate in ATP temperarly removing it, creating energy

Question 40

Proton pump purpose in lysosomes and vacules

Answer 40

To keep the pH low so the enzymes can thrive

Question 41

Calcium pump

Answer 41

In almost all eukaryotes. Pushes Ca2+ from the cytoplasm to the cells exterior and from the cytosol to the ER

Question 42

Uses of the calcium pump

Answer 42

Secretion, microtubule formation, muscle contractions

Question 43

Sodium potassium pump (Na+/K+ pump)

Answer 43

In the plasma membrane. 3 sodium's are pushed out of the cell for every two potassium brought in, leads to positivity outside the cell and negativity inside the cell

Question 44

Voltage

Answer 44

An electrical potential difference

Question 45

Membrane potential

Answer 45

Voltage across a membrane, - means more - inside the cell than out, the basis for ATP production

Question 46

Electrochemical gradient

Answer 46

Stores energy used for other transport mechanisms

Question 47

Secondary ATP pump example

Answer 47

High outside Na+ gradient in most animal cells from sodium potassium pump. Transfer of solute is coupled with the transfer of ions

Question 48

Secondary ATP pump 2 processes

Answer 48

Symport and antiport

Question 49

Symport and example

Answer 49

Uses cotransport. Glucose and amino acids

Question 50

Cotransport

Answer 50

Solute moves though the channel in the same direction as the driving ion

Question 51

Antiport and example

Answer 51

Uses exchange diffusion. Cl- and red blood cells, bicarbonate and membrane channels

Question 52

Exchange diffusion

Answer 52

Driving ion moves in 1 direction providing energy for active transport of a molecule the other way

Question 53

Endo and exocytosis

Answer 53

Largest active transport molecule is an amino acid or monosaccharide. Both need ATP

Question 54

Exocytosis

Answer 54

Removal of molecules from the cell. Used by all eukaryotic cells

Question 55

Endocytosis

Answer 55

Carry protein, molecule parts, or molecules into the cytoplasm.

Question 56

How exocytosis works

Answer 56

Vesicles move through the cytoplasm to the plasma membrane, the membrane fuse and the product is released.

Question 57

How endocytosis works

Answer 57

A depression forms and then pinches off to form an endocytic vesicle.

Question 58

2 pathways of endocytosis

Answer 58

Bulk phase and receptor mediated

Question 59

Bulk phase (pinocytosis)

Answer 59

Water is taken in with the molecule. Nothing binds to any surface receptors

Question 60

Receptor mediated endocytosis

Answer 60

Molecules bond to receptor proteins on the cells surface, then it pinches off.

Question 61

Coated pit

Answer 61

A depression with full receptor sites

Question 62

Clathrin

Answer 62

The network of bonded proteins on the cytoplasmic side . Once a vesicle, the clathrinid membrane dissolves and fuses with a lysosome. The lysosome will dissolve the membrane or the product uses a transport protein to get out

Question 63

Phagocytosis

Answer 63

The process of cells taking in large chunks of cells or molecules

Question 64

steps of phagocytosis

Answer 64

1. surface receptors bind to the molecule 2. Cytoplasmic lobes extend to create a pit and join together 3. The cytoplasm covers the product and digests it using the same process and receptor mediated endocytosis

Question 65

Membrane surface area

Answer 65

Endo and exocytosis make sure it is the proper size