Bio Chap 5.1-5.9

Which of the following is an accurate comparison of active transport and facilitated diffusion?

Active transport moves solutes against their concentration gradient; facilitated diffusion moves substances down their concentration gradient.

Which of the following statements regarding diffusion is false?

Diffusion occurs when particles spread from areas where they are less concentrated to areas where they are more concentrated.

Macrophages are white blood cells that roam the body searching for invading microbes. Inside macrophage vacuoles these invaders are destroyed. How do the microbes get inside the macrophages?

Microbes are engulfed into the macrophage via phagocytosis.

The eukaryotic cell has multiple membrane-enclosed compartments. This evolutionary innovation provides what advantage to the cell?

The different membrane-enclosed spaces allow different parts of the cell to perform specific functions.

Which of the following processes can move a solute against its concentration gradient?

active transport

A major function of glycoproteins and glycolipids in the cell membrane is to

allow the cells of an embryo to sort themselves into tissues and organs.

Aquaporins

allow water to cross the plasma membrane via facilitated diffusion.

If placed in tap water, an animal cell will undergo lysis, whereas a plant cell will not. What accounts for this difference?

If placed in tap water, an animal cell will undergo lysis, whereas a plant cell will not. What accounts for this difference?

When physicians perform an organ transplant, they choose a donor whose tissues match those of the recipient as closely as possible. Which of the following cell components are being matched?

cell surface carbohydrates

New drugs are being developed to lower levels of circulating cholesterol. A successful drug would be one that _____.

increases the rate of LDL receptor-mediated endocytosis

Diffusion does not require the cell to expend ATP. Therefore, diffusion is considered a type of

passive transport

The molecules responsible for membrane transport are

proteins

If placed in tap water, an animal cell will undergo lysis, whereas a plant cell will not. What accounts for this difference?

the relative inelasticity and strength of the plant cell wall

Which of the following substances would have the most trouble crossing a biological membrane by diffusing through the lipid bilayer?

Na+

Utah's Great Salt Lake has an average salinity seven times higher than that of the oceans. Very few multicellular organisms live in this harsh environment. An example is the brine shrimp, which must devote a large portion of its metabolic energy to osmoregulation. These brine shrimp must _____.

actively pump water back into their cells to counter its loss due to osmosis

You're on the pilot episode of a new reality show called "The Transport Factor." The host hands you three different amino acids, four different sugars, and two different ions. Then the host shouts, "How many different proteins does the cell need to move these molecules across the plasma membrane using facilitated transport?" Quickly, you correctly respond: _____

nine

What substance is transported by aquaporins?

water

In an oil-based, nonpolar environment, phospholipds would arrange themselves so that they _____.

would stay together but in a reverse orientation, with their tails projecting outward