Passive Transport and Active Transport

Question 1

what is osmosis

Answer 1

the movement of water molecules from a high concentration to a low concentration (along the concentration gradient) through a semi-permeable membrane

Question 2

what is diffusion

Answer 2

the net movement of particles from a high to low concentration

• is passive (down the concentration gradient)
• does not need a semi permeable membrane

Question 3

what is facilitated diffusion

Answer 3

-occurs through channels

Question 4

what is the rate of diffusion proportional to

Answer 4

-surface are and the concentration gradient

Question 5

what is the rate of diffusion indirectly proportional to

Answer 5

the membrane thickness (length of the diffusion path)

Question 6

what does active transport need

Answer 6

-energy in the form of ATP produced by the mitochondria

Question 7

what is isotonic, hypertonic and hypotonic

Answer 7

Isotonic= equal concentration (equilibrium)
Hypotonic= low concentration of solute
Hypertonic= high concentration of solute

Question 8

what is water potential

Answer 8

water will always move away from pure water to the more negative water potential (high to low concentration)

Question 9

what happens to a solutions water potential when solutes are added

Answer 9

it will falls ad the water molecules will cluster around the solute molecules

Question 10

what is endocytosis

Answer 10

• process by which LARGE substances enter the cell without traveling across the plasma membrane
• invagination of the membrane forms a flask-like depression which envelope material; the invagination is then sealed off forming a vesicle

Question 11

types of endocytosis

Answer 11

• phagocytosis: solid substances

- pinocytosis liquids or solutions

Question 12

what is exocytosis

Answer 12

process by which large substances enter the cell without travelog across a plasma membrane
- vesicles fuse with plasma membrane expelling their contents into the extracellular environment

Question 13

examples of active transport

Answer 13

• small intestine= uptake of glucose and amino acids
• absorption of mineral ions by plant roots
• excretion of urea by kidneys
• exchange of sodium and potation ions in neuron and muscle cells

Question 14

what do cells that undertake large-scale active transport have a lot of

Answer 14

mitochondria

Question 15

what is bulk transport

Answer 15

–when large substances need to be moved across a cell membrane

Question 16

how are vesicles made

Answer 16

by pinching off a piece of the membrane or the Golgi apparatus

Question 17

what is the secretory pathway of exocytosis

Answer 17

nucleus -> rough endoplasmic reticulum -> golgi apparatus -> cell membrane -> outside of cell