learning outcomes chapter 3

Question 1

what does the plasma membrane do?

Answer 1

controls the flow of molecules in and out of all cells

Question 2

what do phospholipids consist of?

Answer 2

Choline
Phosphate
Glycerol
Two fatty acids chains

Question 3

what is cytoplasm?

Answer 3

all cellular material between plasma membrane and the nucleus

Question 4

Explain how cytoplasm and cytosol are different

Answer 4

Cytoplasm
all cellular material between plasma membrane and the nucleus
Cytosol
viscous semitransparent fluid (mostly water) with dissolved protein, salts,
sugars, and other solutes

Question 5

Describe how lipids (phospholipids, cholesterol, lipoproteins) are distributed in a cell membrane, and explain their functions.

Answer 5

Phospholipids: they are distributed by the Fluid Mosaic Model which make up the phospholipid bilayer and allows transport across the membrane of materials in and waste out.

Cholesterol: Helps stabilize the membrane which makes less fluid at body temperature, yet helps maintain fluidity at lower temperatures. 20% of the lipids in the membrane are cholesterol. They are distributed in the phospholipid bilayer by attaching to the Integral Proteins.

Lipoproteins: They allow fats to move through the aqueous solutions inside and outside of the cell and the proteins emulsify the lipid molecules. They are distributed throughout the phospholipid bilayer.

Question 6

describe how proteins are distributed in a cell membrane(integral and peripheral) and explain their functions.

Answer 6

Integral proteins are firmly inserted in the phospholipid bilayer of the membrane, they go through so they are trans membrane. They have many functions such as interacting with the lipid bilayer and the water inside and outside of cell. They can be carrier or channel proteins for transport. they work as enzymes. Or they can be receptors of signals from hormones and chemicals.

Peripheral proteins attach to the membrane on the inside or the outside. They can come off easily. They provide support. Can be enzymes. Help with mechanical movement and change the cell shape in cell division and muscle contractions. Or they can link cells together