Homeostasis & Cell Transport Study Island

The images below show red blood cells surrounded by three different solutions. Each solution was prepared by adding a different amount of a particular solute (sodium chloride) to pure water. In which image is the concentration of solute outside the cells about the same as the concentration of solute inside the cells?

(the image with healthy looking cells)

The images below show red blood cells surrounded by three different solutions. Each solution was prepared by adding a different amount of a particular solute (sodium chloride) to pure water. In which image is the concentration of solute outside the cells greater than the concentration of solute inside the cells?

(the image with the blood cells that are shrived up)

The images below show red blood cells surrounded by three different solutions. Each solution was prepared by adding a different amount of a particular solute (sodium chloride) to pure water. In which image is the concentration of solute outside the cells less than the concentration of solute inside the cells?

(the image with the cells too full)

Osmosis causes water to move from areas of low salt concentration to areas of high salt concentration. The internal NaCl concentration of red blood cells is 0.9 M. The diagram below shows red blood cells submerged in solutions of four different NaCl concentrations—0 M, 0.65 M, 0.9 M, and 2 M. red blood cell osmosis Which of the diagrams shows red blood cells in the 0.65 M solution?

2

Cell membranes (plasma membranes) help organisms maintain homeostasis by controlling what substances may enter or leave cells. Some substances can cross a cell membrane through passive transport, while other substances can only cross a cell membrane through active transport. What is the difference between active and passive cellular transport?

Active transport requires the cell to expend energy, while passive transport does not.

The following diagram is a model of the cell membrane. Though small, nonpolar molecules are usually able to pass freely across the cell membrane, larger molecules and ions can only enter and exit cells through carrier proteins or channel proteins. Adapted from image courtesy of Wikimedia Commons. Using the model above for reference, what effect would the removal of carrier proteins likely have on cell transport?

The movement of glucose molecules into the cell would decrease.

To function normally, many types of animal cells must have a higher concentration of Na+ ions outside the cell and a higher concentration of K+ ions inside the cell. Which of the following forms of cellular transportation helps animal cells maintain Na+/K+ level homeostasis?

a cell membrane pump

Osmosis is the diffusion of water across a selectively permeable membrane in which water moves from a solution containing a low concentration of solute to what kind of solution?

a solution containing a high concentration of solute.

Cells use _______ to take in large molecules or other cells.

active transport by endocytosis

The ________ essentially aids in cellular homeostasis by providing the main transport mechanism for proteins within the cell.

endoplasmic reticulum

Diffusion is the spontaneous movement of a substance from an area of concentration to an area of concentration.

higher to lower

Emphysema is a health condition in which the lungs can no longer expel carbon dioxide normally. As a result, a person who has emphysema may have high blood acidity levels. The body process that would attempt to return the blood pH to normal so that cells could function properly is called _______.

homeostasis

Living organisms are only able to function and thrive if they can maintain constant or stable internal conditions. This ability is known as _______.

homeostasis

The relatively stable state of equilibrium that living systems maintain by regulating their metabolic processes is known as

homeostasis

The Golgi apparatus helps to maintain cellular homeostasis by

modifying, sorting, and packaging proteins prior to transport.

Cells can function

only in a narrow range of temperature and pH.

If the water concentration inside a cell is higher than the water concentration outside the cell, water flows out of the cell. This method of molecular transport is called

osmosis

In carrying out normal activities, cells use oxygen and produce carbon dioxide. The concentration of oxygen is higher in the blood than inside the cell, so oxygen moves into the cell. Similarly, carbon dioxide moves out of the cell into the blood because the concentration of carbon dioxide inside the cell is greater than the concentration outside the cell. How do the small molecules of oxygen and carbon dioxide move through the cell membrane?

passive transport by diffusion

Drag the tiles to the correct boxes to complete the pairs. Simple diffusion, facilitated diffusion, and active transport are three types of cellular transport that occur across cell membranes. Match each term to the correct definition. (1) a type of transport in which a substance moves from an area of high concentration to an area of low concentration with the aid of special transport proteins (2) a type of transport in which a substance moves spontaneously from an area of high concentration to an area of low concentration (3) a type of transport in which a substance moves from an area of low concentration to an area of high concentration through the use of cellular energy

(1) facilitated diffusion (2)simple diffusion (3) active transport

The sodium-potassium pump, shown below, is a mechanism that allows cells to move sodium ions out of the cell and potassium ions into the cell, against a concentration gradient (i.e., from a low concentration to a high concentration). Picture of sodium pump This mechanism maintains the correct concentrations of sodium and potassium ions inside of a nerve cell. Although this pump uses energy, it is necessary to maintain these conditions so nerve impulses can be transmitted properly. Which of the following statements does this information best support?

Living organisms have processes and structures that help them maintain homeostasis.

Normal homeostatic conditions require potassium concentrations to be about 1000 times higher inside the cell than in the blood. What mechanism does a cell use to move these small potassium ions into the cell against the concentration gradient?

active transport by channel proteins

Transmembrane proteins are special proteins embedded within the plasma membrane of cells. What type of membrane protein binds to a molecule on one side of the membrane, then changes shape in order to release the molecule on the other side of the membrane?

carrier proteins

The body's ability to maintain a relatively constant internal environment is called homeostasis. This stability can be challenged by

elevated or depressed blood pH. reduced water or food intake. infectious organisms. extreme temperatures.

The diagram below shows plant cells submerged in solutions with different concentrations of sugar. plant cell osmosis In diagram 1, water is flowing by osmosis out of the cell because the concentration of water

inside the cell is higher than in the surrounding solution.

There are two main ways in which molecules are transported into and out of cells: active transport and passive transport. Which of the following is an example of active transport?

sodium-potassium pump

The cell membrane is a highly selective barrier that controls the movement of substances in and out of the cell. In fact, polar molecules are unable to go across unless

they pass through channels in the cell membrane.

Homeostasis refers to the necessity of an organism to maintain constant or stable internal conditions. What structure helps cells maintain homeostasis by regulating the movement of materials into and out of a cell?

cell membrane

The fluid mosaic model shown above describes the structure and function of

cell membranes.

During heatstroke, the body can't dispose of excess heat. As a result, the homeostatic balance is disturbed, and internal body temperatures can reach as much as 110°. Heatstroke is dangerous to people primarily because

cells can't function properly at high temperatures.

The cell membrane, or plasma membrane, is made up of a lipid bilayer in which hydrophilic heads face outward and hydrophobic tails face inward. phospholipid bilayer The structure of the cell membrane allows it to

control the movement of substances into and out of the cell.