Cell General

The compounds in biological membranes that form a barrier to the movement of hydrophilic materials across the membrane are 

• integral membrane proteins
• carbohydrates
• lipids
• peripheral membrane proteins

In biological membranes, the phospholipids are arranged in a _______, with the_______.

• bilayer; fatty acids pointing toward each other
• bilayer; fatty acids facing outward
• single layer; fatty acids facing the interior of the cell
• single layer; phosphorus-containing region facing the interior of the cell

A characteristic of plasma membranes that helps them fuse during vesicle formation and phagocytosis is the

• ratio of one protein molecule for every 25 phospholipid molecules
• capacity of lipids to associate and maintain a bilayer organization
• constant length of the fatty acid chain and the degree of saturation
• ability of phospholipid molecules to flip over and trade places with other phospholipid molecules

Which statement about cholesterol molecules is true?

• They help hold a membrane together.
• They alter the fluidity of the membrane.
• They attach to carbohydrates.
• They disrupt membrane function.

A protein that forms an ion channel through a membrane is most likely 

• a peripheral membrane protein
• a phospholipid
• an enzyme.
• a transmembrane protein

The hydrophilic regions of a membrane protein are most likely

• present only in muscle cells
• associated with the fatty acid region of the lipids
• either on the surface or inserted into the interior of the membrane
• exposed on the surface of the membrane

Which of the following is found inside a prokaryote?

• cytoplasm
• DNA
• ribosomes
• all of these

When a mouse cell and a human cell are fused, the membrane proteins of the two cells become uniformly distributed over the surface of the hybrid cell. This occurs because

• many proteins can move around within the bilayer.
• all proteins are anchored within the membrane.
• all proteins in the plasma membrane are peripheral.
• different membranes contain different proteins.

If a hospital patient is mistakenly given an IV of pure water instead of a saline solution that is isotonic to blood, the patient’s red blood cells will

• shrink and collapse
• release water to the plasma along its concentration gradient
• absorb water from the plasma and eventually burst
• transport equal amounts of water across the cell membrane in both directions

Tags

NGSS.HS-LS1-3

What type of cell has a nucleus? 

• eukaryotic
• prokaryotic