5.4- Active Transport

Question 1

What is active transport?

Answer 1

The movement of molecules or ion’s into or out of a cell from a region of lower concentration to high concentration

The process requires energy + carrier proteins

Question 2

How does active transport work?

Answer 2

1) molecule binds to receptor on a carrier protein
2) ATP binds to carrier protein and hydrolysis to become ADP + phosphate
3) phosphate molecule causes protein to change shape and open
4) The molecule enters the cell
5) The phosphate molecule is released and becomes ATP again
6) carrier protein returns to its original shape

Question 3

What types of bulks transport are there?

Answer 3

Endocytosis: bulk transport into cells. There are two types:
- phagocytosis: for solids
- pinocytosis: for liquids
Exocytosis: bulk transport out of cells

Question 4

What is the process of endocytosis + exocytosis?

Answer 4

Endocytosis: the cell surface membrane invaginates when it comes into contact with the material being transported.
The membrane enfolds the material until it fuses, forming a vesicle. The vesicle pinches off and moves into the cytoplasm

Exocytosis: vesicles formed via the Golgi apparatus fuse toward the cell membrane The contents of the vesicle are released outside the cell

Question 5

What does ATP do in endo/exocytosis

Answer 5

• Movement of vesicles
• changing shape of cells
• fusion of vesicle