Cell Transport Warm Up: 1

Carrier proteins are integral membrane proteins that are involved in the transport of specific substances across a cell membrane. These proteins bind to the specific molecule they are designed to transport and undergo a conformational change to move the molecule across the membrane. This process is known as facilitated diffusion and it allows for the selective transport of substances such as ions, sugars, and amino acids. Therefore, the statement "The carrier protein is used to transport specific substances across a membrane" is true.

The diagram shows the different directions of osmosis in blood cells. This suggests that osmosis does occur in blood cells and can happen in different directions depending on the concentration gradient.

A hypertonic solution causes a cell to shrink because of osmosis. In a hypertonic solution, the concentration of solutes outside the cell is higher than inside the cell. As a result, water molecules move out of the cell to the area of higher solute concentration, causing the cell to lose water and shrink. This occurs because water moves from an area of lower solute concentration (inside the cell) to an area of higher solute concentration (outside the cell) in order to equalize the solute concentration on both sides of the cell membrane.

The statement is true because there are indeed two main types of endocytosis based on the type of materials that are taken into the cell. These two types are phagocytosis and pinocytosis. Phagocytosis is the process by which solid particles are engulfed by the cell, while pinocytosis is the process by which liquid or dissolved substances are taken in. Therefore, the correct answer is true.

Exocytosis is the process by which substances are transported out of a cell through the fusion of vesicles with the cell membrane. During exocytosis, the vesicle containing the substance fuses with the plasma membrane and releases its contents into the extracellular space. This mechanism is essential for the secretion of molecules such as hormones, neurotransmitters, and digestive enzymes. It allows the cell to communicate with its surroundings and export materials to be used by other cells or tissues.

Phagocytosis is a process in which cells engulf and digest foreign particles such as bacteria and viruses. The cells that perform this function are called phagocytes. They play a crucial role in the immune response by identifying and eliminating pathogens that have entered the body. Phagocytes include various types of white blood cells, such as macrophages and neutrophils. These cells have specialized receptors that recognize and bind to the foreign particles, triggering the process of phagocytosis. Once engulfed, the phagocytes break down the pathogens using enzymes and destroy them, helping to protect the body from infections.

In the second image, the blood cell appears to be in an isotonic condition. This means that the concentration of solutes inside the cell is equal to the concentration of solutes outside the cell. As a result, there is no net movement of water across the cell membrane, and the cell maintains its shape and size.

Active transport is a process that requires energy to move molecules or ions against their concentration gradient. In animal cells, one example of active transport is the sodium-potassium pump. This pump uses ATP energy to actively transport three sodium ions out of the cell and two potassium ions into the cell. This process helps to maintain the concentration gradients of sodium and potassium across the cell membrane, which is important for various cellular functions such as nerve impulse transmission and muscle contraction.

A vesicle is a small sac-like structure within a cell that transports and stores various substances. One of its important functions is to fuse with lysosomes, which are organelles responsible for digestion, so that the contents of the vesicle can be broken down and digested. This process allows the cell to obtain nutrients and recycle waste materials. Therefore, the statement that a vesicle fuses with lysosomes for digestion is true.

Pinocytosis and phagocytosis are the correct answers because they both involve the process of endocytosis, which is the uptake of materials into a cell by engulfing them with the cell membrane. Pinocytosis is the process of taking in small droplets of extracellular fluid, while phagocytosis is the process of engulfing and digesting solid particles or microorganisms. Both processes are important for the cell to obtain nutrients and remove waste materials.

Diffusion refers to the movement of a substance from an area of higher concentration to an area of lower concentration. It occurs naturally and does not require any external energy input. This process is driven by the random motion of particles and aims to achieve equilibrium by evenly distributing the substance throughout the available space. Diffusion is a fundamental process in various biological and physical systems, such as the exchange of gases in the lungs and the movement of molecules across cell membranes.

Osmosis is the transport method responsible for the wrinkling of fingers after sitting in the bathtub for hours. Osmosis is the movement of water molecules from an area of lower solute concentration to an area of higher solute concentration through a semi-permeable membrane. In this case, the water from the bathtub moves into the skin cells of the fingers, causing them to swell and wrinkle.

Facilitated diffusion is the process by which molecules move across a cell membrane with the help of transport proteins. In the image, it is likely that there are transport proteins present on the cell membrane, which are aiding in the movement of molecules from an area of high concentration to an area of low concentration. This is characteristic of facilitated diffusion, making it the correct answer.

The correct answer is "Hypotonic." In the first image of the three, the blood cell appears to be larger and more swollen compared to the surrounding solution. This suggests that the concentration of solutes outside the cell is lower than inside the cell, causing water to move into the cell by osmosis. This results in the cell expanding and becoming hypotonic.

A hypertonic solution actually causes a cell to shrink or shrink because of osmosis. In a hypertonic solution, there is a higher concentration of solutes outside the cell compared to inside the cell. This creates a concentration gradient that causes water to move out of the cell, resulting in the cell shrinking.

Turgor pressure refers to the pressure exerted by water molecules against the cell wall. This pressure is crucial for maintaining the shape and rigidity of plant cells. When the plant cell is fully hydrated, the water molecules exert pressure against the cell wall, creating a turgid state. This pressure helps to support the plant structure and allows plants to stand upright. Turgor pressure also plays a role in various cellular processes, such as nutrient uptake and cell expansion.

The Sodium-potassium pump is an example of a cell membrane "pump" that transports sodium and potassium ions across the cell membrane. It actively pumps three sodium ions out of the cell for every two potassium ions it brings into the cell, using ATP energy. This process is essential for maintaining the proper balance of sodium and potassium ions inside and outside the cell, which is crucial for various cellular functions such as nerve signal transmission and muscle contraction.

Diffusion is the correct answer because it is the process by which molecules move from an area of higher concentration to an area of lower concentration. In this scenario, the student's body odor from not showering would be released into the air and spread to the surrounding area through diffusion, allowing others to detect it.

Plant cells, like animal cells, live in a hypotonic environment surrounded by water. This means that the concentration of solutes outside the cell is lower than inside the cell. Water moves into the plant cells by osmosis, which is the movement of water from an area of higher concentration (outside the cell) to an area of lower concentration (inside the cell).

Simple diffusion is the process of transportation that is taking place when a bottle of ammonia is opened in a room and you can detect an odor 5 meters away. In simple diffusion, molecules move from an area of higher concentration to an area of lower concentration without the need for any energy or assistance from proteins or channels. In this case, the ammonia molecules are spreading out and diffusing through the air, eventually reaching the area 5 meters away where the odor can be detected.

Paramecia have contractile vacuoles to remove excessive amounts of water from the cell. Contractile vacuoles are specialized organelles that pump out excess water to maintain osmotic balance in the cell. Bacteria, bird egg shells, mushrooms, and tigers do not have contractile vacuoles.