Question

1. a friend of yours is taking a new over - the - counter steroid supplement. the steroid comes in a dried powder. she indicates that the powder dissolves completely in water. also, the owner of the store indicated that this steroid contains many \essential\ fatty acids that promote overall health. based on only the information given to you above, explain to your friend why this product may be bogus. chapter 3. cell structure. 1. which process - diffusion, osmosis, or filtration - accounts for the following situations? a. injection of a drug that is hypertonic to the tissues creates a painful sensation b. a person with extremely low blood pressure stops producing urine c. as blood passes through an artificial kidney, the urea (found at high concentrations) leaves the blood and enters the dialyzing fluid of the artificial kidney where urea concentrations are lower d. oxygen moves from the lungs into blood. 2. which characteristic of cell membranes explains why steroids can easily cross them and enter or leave cells? 3. define cancer. explain the difference between a malignant and benign tumor. which type of cancer is usually the easiest to treat? why? many drugs and radiation destroy rapidly dividing cells? why would this treatment be useful against cancer? why are their side - effects to this type of treatment? 4. exposure to tobacco smoke causes cilia to cease moving and degenerate in the trachea. why might this explain the \smokers cough\ and a higher incidence rate of respiratory infections? chapter 24. metabolism. 1. a friend of yours is bitten by the black zancurie spider. the spiders toxin is an enzyme inhibitor that prevents the conversion of pyruvate into acetyl coa. is the reaction listed a catabolic or anabolic reaction? referring to the previous question, these types of reactions are used for what purpose by our cells? if the black zancurie toxin remains within the body, can it be life threatening? why or why not? how do enzyme inhibitors work? 2. what changes in concentrations of oxygen and carbon dioxide would you expect to find in the blood of a person who is forced to exercise on a treadmill beyond his normal capacity? how might these changes affect the persons blood ph? why? would we expect this person to perform a high level under these circumstances? why? 3. fructose is a common sugar found in fruit and most processed foods (pops, sweets, etc). some people have fructose intolerance where they lack the critical enzyme necessary to utilize the sugar as an energy source. however, they can easily metabolize glucose. explain metabolically and in detail why a person with fructose intolerance will feel tired and have a profound lack of energy when they consume a diet high in fructose.

Explanation:

Chapter 3. Cell Structure

1.

• a. Osmosis. A hypertonic drug creates an osmotic gradient, drawing water out of cells and causing pain.
• b. Filtration. Low blood pressure reduces the hydro - static pressure needed for glomerular filtration in the kidneys, thus stopping urine production.
• c. Diffusion. Urea moves from an area of high concentration in the blood to an area of low concentration in the dialyzing fluid.
• d. Diffusion. Oxygen moves from an area of high concentration in the lungs to an area of low concentration in the blood.

2.

Cell membranes are composed of a lipid - bilayer. Steroids are lipid - soluble molecules, so they can easily cross the non - polar lipid - bilayer of cell membranes through simple diffusion.

3.

Cancer is a disorder in which cells lose their ability to control growth and division. A benign tumor is a non - invasive, slow - growing mass of cells that does not spread to other parts of the body. A malignant tumor is invasive, can spread (metastasize) to other tissues and organs. Skin cancer is often the easiest to treat because it is usually detected early, and the cancer cells are localized. Drugs and radiation target rapidly dividing cells because cancer cells divide more rapidly than most normal cells. Side - effects occur because normal rapidly dividing cells (e.g., in bone marrow, hair follicles) are also affected.

4.

Cilia in the trachea move in coordinated waves to sweep mucus and trapped particles out of the respiratory tract. When cilia are damaged by tobacco smoke, mucus and particles accumulate, causing the "smoker's cough" as the body tries to clear the airway. Also, without cilia to remove pathogens, there is a higher incidence of respiratory infections.

Chapter 24. Metabolism

1.

The conversion of pyruvate into Acetyl CoA is a catabolic reaction as it breaks down a larger molecule (pyruvate) into smaller ones and releases energy. Catabolic reactions are used by cells to harvest energy. If the Black Zancurie toxin remains in the body, it can be life - threatening because the conversion of pyruvate to Acetyl CoA is a crucial step in cellular respiration. Enzyme inhibitors work by binding to the enzyme, either at the active site (competitive inhibition) or at an allosteric site (non - competitive inhibition), and preventing the normal substrate from binding or changing the enzyme's shape so it cannot function properly.

2.

During exercise beyond normal capacity, oxygen concentration in the blood decreases as the muscles consume more oxygen. Carbon dioxide concentration increases as the muscles produce more carbon dioxide. The increase in carbon dioxide can lower the blood pH because carbon dioxide combines with water to form carbonic acid, which dissociates into hydrogen ions and bicarbonate ions. The person is not likely to perform at a high level because the change in blood pH can affect enzyme function and muscle contraction.

3.

People with fructose intolerance lack the enzyme needed to metabolize fructose as an energy source. When they consume a fructose - rich diet, fructose cannot be properly broken down and used for energy production. Since they rely mainly on glucose metabolism, and the body's ability to store and use glucose is limited, they experience tiredness and a lack of energy as their cells are not getting sufficient energy from the fructose they consume.

Answer:

Chapter 3. Cell Structure

1.

• a. Osmosis. A hypertonic drug creates an osmotic gradient, drawing water out of cells and causing pain.
• b. Filtration. Low blood pressure reduces the hydro - static pressure needed for glomerular filtration in the kidneys, thus stopping urine production.
• c. Diffusion. Urea moves from an area of high concentration in the blood to an area of low concentration in the dialyzing fluid.
• d. Diffusion. Oxygen moves from an area of high concentration in the lungs to an area of low concentration in the blood.

2.

Cell membranes are composed of a lipid - bilayer. Steroids are lipid - soluble molecules, so they can easily cross the non - polar lipid - bilayer of cell membranes through simple diffusion.

3.

Cancer is a disorder in which cells lose their ability to control growth and division. A benign tumor is a non - invasive, slow - growing mass of cells that does not spread to other parts of the body. A malignant tumor is invasive, can spread (metastasize) to other tissues and organs. Skin cancer is often the easiest to treat because it is usually detected early, and the cancer cells are localized. Drugs and radiation target rapidly dividing cells because cancer cells divide more rapidly than most normal cells. Side - effects occur because normal rapidly dividing cells (e.g., in bone marrow, hair follicles) are also affected.

4.

Cilia in the trachea move in coordinated waves to sweep mucus and trapped particles out of the respiratory tract. When cilia are damaged by tobacco smoke, mucus and particles accumulate, causing the "smoker's cough" as the body tries to clear the airway. Also, without cilia to remove pathogens, there is a higher incidence of respiratory infections.

Chapter 24. Metabolism

1.

The conversion of pyruvate into Acetyl CoA is a catabolic reaction as it breaks down a larger molecule (pyruvate) into smaller ones and releases energy. Catabolic reactions are used by cells to harvest energy. If the Black Zancurie toxin remains in the body, it can be life - threatening because the conversion of pyruvate to Acetyl CoA is a crucial step in cellular respiration. Enzyme inhibitors work by binding to the enzyme, either at the active site (competitive inhibition) or at an allosteric site (non - competitive inhibition), and preventing the normal substrate from binding or changing the enzyme's shape so it cannot function properly.

2.

During exercise beyond normal capacity, oxygen concentration in the blood decreases as the muscles consume more oxygen. Carbon dioxide concentration increases as the muscles produce more carbon dioxide. The increase in carbon dioxide can lower the blood pH because carbon dioxide combines with water to form carbonic acid, which dissociates into hydrogen ions and bicarbonate ions. The person is not likely to perform at a high level because the change in blood pH can affect enzyme function and muscle contraction.

3.

People with fructose intolerance lack the enzyme needed to metabolize fructose as an energy source. When they consume a fructose - rich diet, fructose cannot be properly broken down and used for energy production. Since they rely mainly on glucose metabolism, and the body's ability to store and use glucose is limited, they experience tiredness and a lack of energy as their cells are not getting sufficient energy from the fructose they consume.