Transport

Question 1

2 main types of transport:

Answer 1

active and passive

Question 2

Passive

Answer 2

movement across a membrane without using energy

Question 3

Active

Answer 3

energy dependent

Question 4

TYpes of passive transport

Answer 4

SIMPLE DIFFUSION and faccilitated diffusion
osmosis

Question 5

SIMPLE DIFFUSION

Answer 5

movement of substance across membrane from area of high to low concentration

Small, non-polar
O2, CO2
Small, uncharged polar
Water (slightly)

Question 6

FACILITATED DIFFUSION

Answer 6

diffusion has to be helped by proteins in the membrane.

Question 7

what are TRANSPORT PROTEINS

Answer 7

are integral membrane proteins and come in 2 types:
CHANNEL PROTEINS
CARRIER PROTEINS
aquaporin (type of channel protein)

Question 8

CHANNEL PROTEINS

Answer 8

form hydrophilic pathways in the membrane so H2O and some ions can pass

Question 9

CARRIER PROTEINS

Answer 9

also form passageways, but bind to specific solutes. ex: glucose
these are specific which allows for tight control. ex: the glc carrier protein won’t bind fructose.

Question 10

OSMOSIS

Answer 10

passive diffusion of water across membrane

water always diffuses from an area of low solute concentration to an area of higher solute concentration.

osmosis can cause cells to swell or shrink

Question 11

hypertonic

Answer 11

has a higher concentration of solutes (and therefore a lower concentration of water) than cell’s cytoplasm, causing water to move out of the cell, leading to shrinkage

Question 12

hypotonic

Answer 12

lower concentration of solutes (and therefore a higher concentration of water) compared to cell’s internal environment. This difference in solute concentration causes water to move into the cell, potentially leading to swelling or bursting.

Question 13

PRIMARY Active Transport
molecular actice transport

Answer 13

pumps that move positively charged ions across membranes

	ex: Calcium pump moves
 				Ca2+ from cytosol to the 					
			cell exterior

	ex: sodium-potassium pump pushes 
			3 Na+ out of cell and 2 K+ 
			into the cell

This creates unequal charge distribution (more + on outside of cell) and we create an electrochemical gradient. This is stored potential energy

Question 14

Bulk transport

Answer 14

movement of large molecules using vesicles
exocytosis, endocytosis

Question 15

Exocytosis

Answer 15

a vesicle fuses with the cell membrane are released and its membrane becomes aprt of teh cell

Question 16

endocytosis

Answer 16

the cell membrane surrounds a per of the exterior environment and buds off as a vesicle

Question 17

types of endocytotsis

Answer 17

receptor mediated endocytosis
phagocytosis
pinocyotist

Question 18

receptor mediated endocyosis

Answer 18

The receptors on the membrane have a specific shape that matches the target molecule (like hormones, nutrients, or even viruses).

After the receptor binds to the specific molecule, clathrin (a protein) forms a coated pit, helping to form the vesicle.

The vesicle buds off the membrane, detaches, and transports the cargo into the cytoplasm.

Question 19

Phagocytosis

Answer 19

cell engulfs large particles, such as debris, foreign substances, or microorganisms (like bacteria or viruses). It’s a crucial process for immune cells, like macrophages and neutrophils.

cell extends its pseudopodia (temporary projections of the cytoplasm) around the particle.

The pseudopodia fuse, enclosing the particle in a vesicle called a phagosome.

The phagosome then fuses with a lysosome, where the contents are digested by enzymes.

Question 20

Pinocytosis (Cell Drinking

Answer 20

cell engulfs small amounts of extracellular fluid, along with dissolved solutes
The cell membrane invaginates (folds inward), forming small vesicles that take in extracellular fluid and dissolved substances.

Unlike receptor-mediated endocytosis, there is no specific recognition of the substances being internalized.

The vesicle forms, and then it buds off the membrane to transport the fluid into the cytoplasm.