Lecture 4: Jihan Notes

Question 1

What are the four types of passive transport?

Answer 1

1. Diffusion
2. Osmosis
3. Filtration
4. Facilitated diffusion (with a protein channel intermediate)

Question 2

Why is the Na-K pump termed primary active transport, and why is it neede?

Answer 2

It directly uses ATP, which is necessary for Na and K to go against their concentration gradients

Question 3

Why way to Na and K flow in the Na-K pump?

Answer 3

K goes into the cell and Na out of the cell. Both are against their concentration gradient.

Question 4

Why are glucose and sodium an example of secondary active transport in the gut?

Answer 4

As secondary active transport uses a gradient set up with indirect use of energy, sodium comes into the enterocyte and glucose follows into the cell

Question 5

Is antiport an example of primary or secondary active transport?

Answer 5

Secondary; sodium goes into the cell as it flows down its ionic gradient and glucose leaves the cell and enters the blood vessel

Question 6

Why are lipid-bound proteins rare in relation to their function with the outside environment?

Answer 6

Proteins are normally used to interacting with the extracellular environment, which is hydrophilic. So with the lipid attached, they cannot interact with outside of the cell.

Question 7

How do channel proteins relate to the concentration gradient?

Answer 7

The channels provide a mechanism by which ions can move down their gradient either into or out of a cell

Question 8

Carrier proteins: they sometimes use ATP, which indicates they do what function?

Answer 8

They transport molecules, either into or out of a cell, AGAINST the concentration gradient.

Question 9

How are glycoproteins used in signaling?

Answer 9

The glucose placed on the protein is used to detect cells of bad diseases, like Alzheimer’s. So an abnormality of the sugar can stop the cell from defending itself.