Gas Echange Cell Membranes And Transport(topic 2)

Question 1

What is diffusion

Answer 1

Net movement of particles from a area of high concentration to a area of low concentration

Question 2

2 adaptations of gas exchange surfaces

Answer 2

Large surface area to volume ratio

Short diffusion distance

Question 3

What is ficks law

Answer 3

Rate of diffusion= area of diffusion surface x difference in concentration divided by thickness of diffusion distance

Question 4

What is a passive process

Answer 4

No energy required for it to happen

Question 5

What kind of structure do cell membranes have

Answer 5

Fluid mosaic structure

Question 6

3 structural features of cell membranes

Answer 6

Arranged in a Phospholipid bilayer

Heads are hydrophilic attract water so face outwards

Tails are hydrophobic so repel water and are located inside

Question 7

How do molecules pass through a cell membrane

Answer 7

Small molecules can pass through the membrane as it is partially permeable

Larger molecules pass through channel proteins and Carrier proteins

Question 8

what is osmosis

Answer 8

diffusion of water a partially permeable membrane from high concentration to low concentration

Question 9

how do carrier proteins work

Answer 9

large molecule attaches to a carrier proteins

protein then changes shape which the releases the molecule on the other side

Question 10

how do channel proteins work

Answer 10

channel proteins form pores for charged particles to pass through.

Question 11

what is active transport

Answer 11

uses energy to move molecules against a concentration gradient.energy produced by atp release

Question 12

What does cholesterol do In a cell memebrane

Answer 12

Increases rigidity by forming bonds in between it and the phospholipids

Question 13

Explain endocytosis into a cell

Answer 13

Molecule to large to enter through carrier proteins

Cell can surround a substance with a section of a cell membrane

Membrane then pinches off to form a vesicle inside the cell containing the ingested molecule

ATP used for this process

Question 14

Explain exocytosis out of a cell

Answer 14

When a large molecule need to leave a cell vesicle pinch off from the Golgi apparatus and move towards the cell membrane the. The vesicles fuse with the cell membrane and release their contents

Also use ATP as a energy source

Question 15

Explain the difference between endocytosis and exocytosis

Answer 15

Endocytosis is movement into a cell membrane whereas exocytosis is out of a cell memebrane