Question 1

A type of transport protein found in the plasma membrane of cells lining the inside of the intestine allows sodium ions to diffuse down their concentration gradient. The ions move through the transport protein, and into the cell. These transport proteins will use the kinetic energy of the diffusing sodium ions to bring glucose into the cells as well. Which of the following would stop transport of glucose through this transport protein?

Accepted Answer

The transport protein relies on the movement of sodium ions down their concentration gradient to bring glucose into the cell. This movement of sodium ions is maintained by the sodium potassium pump, which actively transports sodium ions out of the cell to maintain a low concentration of sodium inside the cell. If the activity of the sodium potassium pump is stopped, the concentration gradient for sodium ions will eventually equalize, and there will be no gradient to drive the movement of glucose into the cell. Therefore, stopping the activity of the sodium potassium pump would stop transport of glucose through this transport protein.

Question 2

Beta cells in the pancreas produce and secrete the protein hormone insulin. You would expect to see a relatively large amount of which organelles in these cells?

Accepted Answer

Beta cells in the pancreas produce and secrete insulin, which is a protein hormone. Protein synthesis occurs in the rough endoplasmic reticulum (ER), and the Golgi apparatus modifies, sorts, and packages proteins for secretion. Therefore, we would expect to see a relatively large amount of rough ER and Golgi apparatus in beta cells. Mitochondria are important for energy production and cilia are involved in movement, neither of which are directly related to the production of insulin. Smooth ER and lysosomes have different functions than the ones required for protein synthesis and secretion. Cytoskeleton and peroxisomes also do not play direct roles in protein hormone synthesis and secretion.

Question 3

Describe two important functions of the Golgi apparatus.

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Question 4

A red blood cell would swell if its surrounding solution were .

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The answer of A red blood cell would swell if...

Question 5

The most common intracellular cation is _________.

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The answer of The most common intracellular cation is _________....

Question 6

Are random moments of particles, diffusion, and osmosis seen only in living tissue?

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Question 7

The phase of a cell life cycle in which the DNA is replicated is called _________.

Accepted Answer

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Question 8

If a cell is selectively reducing the concentration of a particular enzyme in the extracellular fluid it will likely utilize __________ .

Accepted Answer

Receptor-mediated endocytosis is a selective process where cells can specifically internalize certain molecules or proteins that bind to specific receptors on the cell surface. This is likely the mechanism that a cell would utilize in order to selectively reduce the concentration of a particular enzyme in the extracellular fluid. Pinocytosis and phagocytosis are non-selective processes that would not be able to distinguish between the enzyme and other molecules in the extracellular fluid. Exocytosis is the process of releasing substances from a cell into the extracellular fluid, and would not be involved in reducing the concentration of a particular enzyme in the extracellular fluid.

Question 9

What processes maintain a steady state "resting" membrane potential?

Accepted Answer

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Question 10

A type of transport protein found in the plasma membrane of cells lining the inside of the intestine allows sodium ions to diffuse down their concentration gradient. The ions move through the transport protein, and into the cell. These transport proteins will use the kinetic energy of the diffusing sodium ions to bring glucose into the cells as well. This transport protein would best be described as __________.

Accepted Answer

The transport protein is allowing the movement of both sodium and glucose across the plasma membrane, making it a symporter. A channel would allow only one type of ion or molecule to pass through, while a carrier protein would only move one type of molecule at a time. A pump requires energy to actively move substances against their concentration gradient, which is not happening in this case.

Question 11

If a cell is non-selectively engulfing samples of extracellular fluid, for example to absorb nutrients, it will likely utilize __________ .

Accepted Answer

Non-selective engulfing of samples of extracellular fluid is the process of taking in small droplets of fluid or solutes into the cell through its membrane. This process is called pinocytosis. Receptor-mediated endocytosis is a specific process where receptors bind to specific ligands in the extracellular fluid. Exocytosis is the process of releasing cellular products outside of the cell. Phagocytosis is a process where the cell engulfs large particles or microorganisms.

Question 12

Water may move through membrane pores constructed by transmembrane proteins called _________.

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Question 13

Which of the following would NOT assist in establishing a resting membrane potential?

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Question 14

Why can we say that a cell without a nucleus will ultimately die?

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Question 15

The process of discharging particles from inside a cell to the outside is called _________.

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Question 16

Myocardium (cardiac muscle tissue) must rhythmically contract for a lifetime. This requires a considerable amount of energy production by the cells. You would expect to see a relatively high amount of which organelle in these cells?

Accepted Answer

Mitochondria are responsible for energy production in cells through cellular respiration. Since myocardial cells require a significant amount of energy to rhythmically contract throughout a person's lifetime, they would have a large amount of mitochondria to meet this demand.

Question 17

Aerobic cellular respiration occurs in the_________ .

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Question 18

_________is the division of the cytoplasmic mass into two parts.

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Question 19

When tissues are injured or infected, chemical signals can be releases that affect the plasma membrane of cells that line the nearby blood vessels. These blood vessels' cells (endothelial cells) respond to the chemical signals by displaying a type of glycoproteins on their surface. These proteins will attach to circulating white blood cells bringing them to the site of injury or infection. These glycoproteins would best be described as .

Accepted Answer

Cell Adhesion Molecules (CAMs) are glycoproteins that are involved in cell-to-cell adhesion and play a crucial role in several physiological and pathological processes, including inflammation and immune responses. CAMs are expressed on the surface of endothelial cells and interact with white blood cells, promoting their adhesion, and extravasation to the site of tissue injury or infection, allowing them to perform their protective function.

Question 20

Colchicine is a drug that can prevent the formation of microtubules. Which is the most likely effect colchicine would have on cell division?

Accepted Answer

Colchicine prevents the formation of spindle microtubules, which are crucial for proper segregation of chromosomes during mitosis. Therefore, the drug would likely arrest mitosis.

Quiz 3: Cells: the Living Units