Question 1

Refer to the figure below.  The figure shows a type of facilitated diffusion that involves a membrane protein called a(n) _______ protein.This example is similar to all other examples of facilitated diffusion in that it does not require the input of energy to move substances across a biological membrane.

Accepted Answer

The answer of Refer to the figure below.  The...

Question 2

Integrins are transmembrane proteins that can reversibly link the cytoskeleton of a cell to the extracellular matrix.When there is a transient period during which the cytoskeleton is not linked to the extracellular matrix, the result may be

Accepted Answer

When there is a transient period during which the cytoskeleton is not linked to the extracellular matrix, cells can move through the extracellular matrix using integrins as adhesion molecules. This process is important for cell migration during processes such as wound healing and embryonic development.

Question 3

Refer to the table below.  The phospholipids in the cell membranes of a fish species were observed to undergo a change in fatty acid composition when the fish were shifted from one environmental condition to another.Data from an investigation reporting these observations are shown in the table.What property of cell membranes is affected by this change, and how is this property affected?

Accepted Answer

The answer of Refer to the table below.  The...

Question 4

The speed and direction of ions as they move through channels in the cell membrane are determined by the

Accepted Answer

The answer of The speed and direction of ions as...

Question 5

Mice embryos that have a defective gene for the membrane protein integrin display a lack of migration of neural cells within their developing brains.This can be explained by the fact that neural cell movements are mediated by cycles of integrin attachment and detachment to proteins in the _______.

Accepted Answer

The answer of Mice embryos that have a defective gene...

Question 6

The structure of a biological membrane is best described by the _______ model.

Accepted Answer

The fluid mosaic model is the best description of the structure of a biological membrane because it accurately illustrates the dynamic nature of the lipid bilayer membrane and the mosaic-like distribution of proteins and other molecules within it. The plasma membrane refers specifically to the membrane surrounding a cell, while the phospholipid bilayer and hydrophilic core are components of the membrane structure but do not fully describe its complexity. Fatty acid is a component of the membrane lipids but does not describe the overall structure.

Question 7

Refer to the figures below.  The figures show the experimental procedure and results of an investigation.The phospholipids of the cell membrane of a single cell were chemically reacted with a small fluorescent molecule so that there was uniform labeling of the fluorescent molecule across the membrane.The labeled cell was placed under a fluorescent microscope and observed as light from a laser was directed at a small region of the cell for a microsecond.The light bleached (damaged) the fluorescent molecules in that region so that the molecules were no longer able to fluoresce.In the time period following the bleaching event, recovery of fluorescence in the bleached region was observed and graphed.These results support which statement about cell membranes?

Accepted Answer

The experiment described in the figures involves observing the recovery of fluorescence in a bleached region of a cell membrane composed of phospholipids. The fact that fluorescence recovery is observed suggests that the phospholipids in the membrane are in constant flux and interact noncovalently. This supports choice D. The other answer choices are not directly related to the experimental results described.

Question 8

Carbohydrates play a role in the biological membrane as recognition sites for other cells and molecules.They covalently bind to a protein in the membrane to form

Accepted Answer

Carbohydrates covalently bind to a protein in the membrane to form glycoproteins, which act as recognition sites for other cells and molecules. Transmembrane proteins refer to proteins that span the entire membrane, while phospholipids and lipid proteins refer to different components of the membrane. Plasma bilayers may refer to the overall structure of the membrane, but do not specifically involve carbohydrates.

Question 9

A unicellular organism adapted to living in salt water is placed in a freshwater tank.What is the likely outcome?

Accepted Answer

When a unicellular organism adapted to living in salt water is placed in freshwater, the external environment is hypotonic compared to the internal environment of the cell. This causes water to move into the cell through osmosis, potentially leading to the cell bursting due to the increased internal pressure.

Question 10

Refer to the figure below.  This cell uses _______ to move this substance against its concentration gradient.

Accepted Answer

The answer of Refer to the figure below.  This...

Question 11

Refer to the figures below.  The correct sequence of figures for showing the process of endocytosis is _______.

Accepted Answer

The answer of Refer to the figures below.  The...

Question 12

Which statement about diffusion is false?

Accepted Answer

Simple diffusion does not depend on specific carrier or channel proteins. It is the movement of molecules across a membrane from an area of high concentration to an area of low concentration, without the need for a specific protein to facilitate the movement. Facilitated diffusion, however, does rely on specific carrier or channel proteins to allow molecules to pass through the membrane.

Question 13

_______ proteins are embedded in biological membranes while _______ proteins are associated with surface regions of biological membranes.

Accepted Answer

Integral proteins are embedded within the membrane while peripheral proteins exist on the surface of the membrane. Transmembrane proteins are a subset of integral proteins that span the membrane from one side to the other. Cytoskeletal proteins are not typically associated with the membranes, but rather provide structural support within the cell. Extracellular proteins are not typically associated with membranes, but rather exist outside of the cell. Therefore, choice C, integral and peripheral proteins, accurately describes the two different types of membrane-associated protein locations.

Question 14

Refer to the figure below.  This diagram can be used to describe two cellular processes that involve membrane proteins.As shown in box A, the process of cell recognition refers to the specific interactions between carbohydrate groups and amino acid groups that allow one cell to identify another cell.As shown in box B, the process of cell _______ results from the strong linkage of two membrane-embedded molecules from two different cells.

Accepted Answer

The answer of Refer to the figure below.  This...

Question 15

Refer to the figure below.  How should the indicated parts of the diagram be labeled?

Accepted Answer

The answer of Refer to the figure below.  How...

Question 16

Osmosis is a specific form of

Accepted Answer

Osmosis is a type of diffusion that involves the movement of water molecules from an area of higher concentration to an area of lower concentration across a selectively permeable membrane. It does not require energy, which means it is a passive process. Therefore, option C - diffusion, is the correct answer.

Question 17

Adjacent animal cells may be bound together by _______, _______, and _______.

Accepted Answer

Tight junctions form a barrier between cells, preventing movement of molecules between them. Gap junctions allow small molecules and ions to pass between cells, allowing them to communicate. Desmosomes anchor cells together and provide structural support.

Question 18

All of the following processes occur in normal cell development and metabolism.Which pair of processes is most important during development when cells are aggregating into tissues?

Accepted Answer

During the development when cells are aggregating into tissues, cell recognition and cell adhesion are most important processes as these processes ensure specific cells bind together to form tissues with a particular function. This process is crucial in the formation of organs and tissues during development.

Question 19

Refer to the figure below.  The figure shows the molecular structures of urea and diethylurea.Both molecules can pass through biological membranes via simple diffusion, but diethylurea will diffuse through a membrane at a rate 50 times greater than that of urea.This is because diethylurea is _______ nonpolar than urea.

Accepted Answer

The answer of Refer to the figure below.  The...

Question 20

Refer to the figure below.  Areas A and B are separated by a membrane that is permeable to a substance X.Which set of conditions will result in the greatest rate of diffusion of X into area A?

Accepted Answer

The answer of Refer to the figure below.  Areas...

Quiz 6: Cell Membranes

Integrins are transmembrane proteins that can reversibly link the cytoskeleton of a cell to the extracellular matrix.When there is a transient period during which the cytoskeleton is not linked to the extracellular matrix, the result may be

The speed and direction of ions as they move through channels in the cell membrane are determined by the

Mice embryos that have a defective gene for the membrane protein integrin display a lack of migration of neural cells within their developing brains.This can be explained by the fact that neural cell movements are mediated by cycles of integrin attachment and detachment to proteins in the _______.

The structure of a biological membrane is best described by the _______ model.

Carbohydrates play a role in the biological membrane as recognition sites for other cells and molecules.They covalently bind to a protein in the membrane to form

A unicellular organism adapted to living in salt water is placed in a freshwater tank.What is the likely outcome?

Refer to the figure below. This cell uses _______ to move this substance against its concentration gradient.

Refer to the figures below. The correct sequence of figures for showing the process of endocytosis is _______.

Which statement about diffusion is false?

_ proteins are embedded in biological membranes while _ proteins are associated with surface regions of biological membranes.

Refer to the figure below. How should the indicated parts of the diagram be labeled?

Osmosis is a specific form of

Adjacent animal cells may be bound together by ___, _, and _____.

All of the following processes occur in normal cell development and metabolism.Which pair of processes is most important during development when cells are aggregating into tissues?