Unit 2 Quiz 2 Review

The “Fluid” in the Fluid Mosaic Model refers to:

• Cholesterol and carbohydrates

• Lipids & proteins moving laterally

• Only phospholipids

• DNA & RNA

The “Mosaic” in the Fluid Mosaic Model is due to a mix of:

• Nucleic acids

• Phospholipids, proteins, cholesterol, glycoproteins, glycolipids

• Enzymes only

• Ribosomes and RNA

Phospholipid heads are _____, while tails are _____

• Phospholipid heads are hydrophilic, while tails are hydrophobic.

• Phospholipid heads are hydrophobic, while tails are hydrophilic.

• Phospholipid heads are nonpolar, while tails are polar.

• Phospholipid heads are neutral, while tails are charged.

Cholesterol helps stabilize _____ by preventing membranes from _____ in cold and _____ in heat.

• membranes; solidifying; becoming too fluid

• proteins; denaturing; breaking down

• enzymes; freezing; melting

• cells; shrinking; expanding

Integral proteins span the _____, while peripheral proteins are found on the _____.

• Integral proteins span the membrane, while peripheral proteins are found on the surface.

• Integral proteins span the cytoplasm, while peripheral proteins are found on the nucleus.

• Integral proteins span the nucleus, while peripheral proteins are found on the cytoplasm.

• Integral proteins span the surface, while peripheral proteins are found on the membrane.

In cold environments, organisms increase the amount of _____ fatty acid tails to keep membranes _____.

• unsaturated

• saturated

• branched

• short-chain

Tags

NGSS.HS-LS4-4

Which adaptation allows Arctic fish membranes to stay flexible in icy water?

• Saturated fatty acids

• Integral proteins

• Unsaturated fatty acids

• More cholesterol

Selective permeability means:

• Everything can pass freely

• Only water can pass freely

• Some substances can pass, others cannot

• Nothing can pass

Which molecules can pass freely through the membrane?

• O2, CO2, N2

• Glucose, ions, proteins

• Water only

• DNA and RNA

Polar molecules such as _____ and _____, and _____ need transport proteins.

• water and glucose, and ions

• oxygen and carbon dioxide, and lipids

• starch and cellulose, and fatty acids

• urea and ethanol, and gases