1.
What is the basic structure of all cell membranes?
Correct Answer
A. The pHospHolipid bilayer with many embedded proteins
Explanation
The basic structure of all cell membranes is the phospholipid bilayer with many embedded proteins. The phospholipid bilayer consists of two layers of phospholipids, with their hydrophilic heads facing outward and their hydrophobic tails facing inward. This structure provides a barrier that separates the internal contents of the cell from the external environment. The embedded proteins within the phospholipid bilayer play various roles such as transport of molecules across the membrane, signal transduction, and cell adhesion. These proteins are essential for the proper functioning of the cell membrane.
2.
A membrane is a continuous, selectively permeable barrier
Correct Answer
A. True
Explanation
A membrane is a continuous, selectively permeable barrier that allows certain substances to pass through while blocking others. This statement is true because membranes are made up of phospholipids arranged in a bilayer, with hydrophobic tails facing inward and hydrophilic heads facing outward. This structure creates a barrier that only allows small, nonpolar molecules to pass through freely, while larger or charged molecules require specific transport proteins to cross the membrane. Therefore, membranes play a crucial role in regulating the movement of substances in and out of cells, making the statement true.
3.
You are at work and a new animal health student comes in. You decide to help her homework by Checking the components of a phospholipid molecule. ( Include vague and detailed answers)
Correct Answer(s)
A. pHospHate
C. A pHospHate head with two fatty acids tails
E. The polar head is hydropHilic
F. The polar head --> hydropHilic means it interacts with water molecules
H. Nonpolar tails : hydropHobic
Explanation
The phospholipid molecule consists of a phosphate group attached to a glycerol backbone, with two fatty acid tails. The phosphate head of the molecule is hydrophilic, meaning it has an affinity for water molecules and can interact with them. On the other hand, the fatty acid tails are hydrophobic, meaning they do not interact with water molecules. Therefore, the polar head of the phospholipid molecule interacts with water, while the nonpolar tails repel water.
4.
Phosphatidylcholime is the most uncommon phospholipid component of all animal cell membranes.
Correct Answer
B. False
Explanation
It is the MOST common.
5.
What state is the lipid bilayer found in?
Correct Answer
B. Liquid: fluid
Explanation
The lipid bilayer is found in a liquid or fluid state. This is because lipids are hydrophobic molecules that form a double layer in an aqueous environment. The fluidity of the lipid bilayer allows for the movement of molecules and proteins within the cell membrane, which is crucial for various cellular processes such as cell signaling and membrane transport.
6.
What is the word to explain that a cell membrane allows certain substances to pass through and not others? ( No capitals)
Correct Answer
semipermeable
Explanation
A cell membrane is described as semipermeable because it selectively allows certain substances to pass through while blocking others. This means that it permits the passage of specific molecules or ions based on their size, charge, or solubility, while restricting the movement of others. The term "semipermeable" accurately captures this characteristic of the cell membrane, making it the correct answer.
7.
What is a vesicle?
Correct Answer
A. ....a small membrane-enclosed sack that can store or transport substances.
Explanation
A vesicle is a small membrane-enclosed sack that can store or transport substances. This definition accurately describes the nature and function of a vesicle. Vesicles are involved in various cellular processes such as the transport of molecules within a cell and the secretion of substances outside the cell. They are formed from the cell membrane and contain a variety of molecules including proteins, lipids, and other cellular components. The membrane surrounding the vesicle allows it to selectively transport and store substances, making it an essential component in cellular functioning.
8.
Which of these answers is a correct reason in differences in membrane composition?
Correct Answer
C. Different kind of cells have different kinds of membranes
Explanation
Different kind of cells have different kinds of membranes because the composition of membranes can vary depending on the specific cell type. Each cell type requires a unique set of membrane proteins and lipids to perform its specific functions. This variation in membrane composition allows cells to have different properties and perform different functions in the body.
9.
Is it true that a cell membrane helps vesicles forms?
Correct Answer
A. True
Explanation
The cell membrane plays a crucial role in the formation of vesicles. Vesicles are small sacs made up of lipid bilayers, similar to the cell membrane. These sacs can transport molecules within the cell or to the cell's exterior. The process of vesicle formation, known as budding, occurs when a portion of the cell membrane pinches off to create a vesicle. This process is facilitated by specific proteins and lipids present in the cell membrane. Therefore, it is true that the cell membrane helps vesicles form.
10.
A cell membrane brings together the contents of a cell from its surroundings.
Correct Answer
B. False
Explanation
False. It seperates.
11.
Through protein channels, a cell membrane can control the movement of materials into and out of the cell.
Correct Answer
A. True
Explanation
Protein channels in the cell membrane play a crucial role in regulating the movement of materials into and out of the cell. These channels act as gatekeepers, allowing specific molecules or ions to pass through while blocking others. By selectively controlling the flow of substances, the cell can maintain homeostasis and ensure that essential nutrients enter the cell while waste products and toxins are expelled. This process is vital for the proper functioning of cells and is facilitated by protein channels embedded within the cell membrane.
12.
The cell membrane interacts with the environment surrounding the cell.
Correct Answer
A. True
Explanation
The cell membrane is a selectively permeable barrier that separates the internal environment of the cell from the external environment. It plays a crucial role in regulating the movement of substances in and out of the cell, allowing for the exchange of nutrients, waste products, and signaling molecules with the surrounding environment. Through various mechanisms such as receptor proteins and ion channels, the cell membrane enables the cell to interact and respond to changes in its external environment, making the statement true.
13.
What does a fluid mosaic model describe?
Correct Answer
A. The organisation of cell membranes.
Explanation
The fluid mosaic model describes the organization of cell membranes. This model suggests that the cell membrane is composed of a fluid lipid bilayer with embedded proteins. The lipids in the membrane can move laterally, giving the membrane fluidity. The proteins within the membrane can also move and float within the lipid bilayer, creating a mosaic-like pattern. This model helps to explain how the cell membrane functions as a selectively permeable barrier, allowing certain molecules to enter and exit the cell while maintaining its structural integrity.
14.
The bilayer is a mosaic mixture of:
Correct Answer(s)
A. Interacts with the environment surrounding the cell
B. Glycolipids - oligosaccharides
C. Sterols - in animals: cholesterol; in plants: pHytosterols
D. Proteins with many functions
H. Fluids
K. Surfaces differ
Explanation
The correct answer includes the statement "interacts with the environment surrounding the cell," which refers to the bilayer of the cell membrane. This statement indicates that the bilayer is involved in interactions with the external environment. The answer also mentions other components of the bilayer, such as glycolipids (oligosaccharides), sterols (cholesterol in animals and phytosterols in plants), proteins with various functions, and the presence of fluids. Additionally, it states that the surfaces of the bilayer differ, suggesting that the two layers of the bilayer have distinct properties.
15.
Correct Answer
A. This is a fluid
16.
Is the phospholipid flexible? Does its fluidity allow lateral movement?
Correct Answer
A. Yes and yes.
Explanation
Phospholipids are flexible molecules due to the presence of a hydrophobic tail and a hydrophilic head. This flexibility allows them to move laterally within the cell membrane. The fluidity of phospholipids enables various cellular processes such as the movement of proteins, lipids, and other molecules within the membrane. Therefore, the correct answer is "Yes and yes."
17.
What does fluidity depend on to cause differences?
Correct Answer
A. Temperature and lipid composition.
Explanation
Fluidity refers to the ability of molecules to move within a substance. In the context of this question, it is referring to the fluidity of cell membranes. The fluidity of cell membranes depends on two factors: temperature and lipid composition. Temperature affects membrane fluidity because it influences the movement of lipid molecules. As temperature increases, the lipid molecules move more rapidly, increasing membrane fluidity. Lipid composition also plays a role in membrane fluidity as different types of lipids have different properties. Lipids with unsaturated fatty acids have kinks in their tails, which prevents them from packing tightly together, resulting in a more fluid membrane. Therefore, temperature and lipid composition are the factors that cause differences in membrane fluidity.
18.
Do warmer temperature make the fluidity more efficient?
Correct Answer
A. Yes
Explanation
Warmer temperatures generally increase the kinetic energy of molecules in a fluid, causing them to move more quickly and collide more frequently. This increased molecular motion leads to decreased viscosity and increased fluidity, making the fluid flow more efficiently. Therefore, warmer temperatures do make the fluidity more efficient.
19.
How do B cell receptors help?
Correct Answer
A. They help the body eliminate toxins and infectious agents such as bacteria.
Explanation
B cell receptors play a crucial role in the immune response by recognizing and binding to specific antigens present on pathogens such as bacteria. This binding triggers a series of events that lead to the elimination of the pathogens, either by directly neutralizing them or by activating other immune cells to attack and destroy them. Therefore, B cell receptors help the body eliminate toxins and infectious agents, contributing to the overall defense against infections.
20.
ATP synthases to make ATP, but only does when _____ flows through its interior.
Correct Answer
A. H+
Explanation
ATP synthases are enzymes that are responsible for synthesizing ATP, the energy currency of cells. They do so by utilizing the energy from a proton (H+) gradient across a membrane. This gradient is generated by the movement of protons from an area of high concentration to an area of low concentration. Therefore, ATP synthases only function when H+ ions flow through their interior, allowing them to harness the energy from this movement and convert it into ATP.
21.
Calcium pumps move calcium ions across the membrane, but require ____ energy.
Correct Answer
D. ATP
Explanation
Calcium pumps are responsible for moving calcium ions across the membrane. This process requires energy in the form of ATP. ATP is a high-energy molecule that provides the necessary energy for cellular processes, including the movement of ions. Therefore, ATP is required for the functioning of calcium pumps and the transportation of calcium ions across the membrane.
22.
What is the function of adhesion proteins?
Correct Answer
A. ..attach of a cell to another and to extrcellular matrix
Explanation
Adhesion proteins play a crucial role in attaching a cell to another cell and to the extracellular matrix. These proteins are responsible for maintaining the structural integrity of tissues and organs by allowing cells to adhere to their surroundings. They facilitate cell-cell communication, cell migration, and tissue development. Without adhesion proteins, cells would not be able to properly adhere to each other or to the extracellular matrix, leading to disrupted tissue organization and impaired cellular function.
23.
Where is the adhesion protein located on the membrane?
Correct Answer
A. Integral
Explanation
The adhesion protein is located on the membrane in an integral position. Integral proteins are embedded within the lipid bilayer of the cell membrane, allowing them to interact with both the interior and exterior of the cell. This positioning is essential for the adhesion protein to fulfill its function of mediating cell-cell or cell-matrix interactions. Peripheral proteins, on the other hand, are located on the surface of the membrane and do not penetrate the lipid bilayer. Therefore, the correct answer is integral.
24.
What is the function of an enzyme? ( You better get this one!)
Correct Answer
A. To speed up a chemical reaction
Explanation
Enzymes are biological catalysts that increase the rate of chemical reactions by lowering the activation energy required for the reaction to occur. They do this by binding to the reactant molecules and facilitating the formation of the transition state, which leads to the formation of products. This allows the reaction to occur more quickly, making enzymes essential for various biological processes such as digestion, metabolism, and DNA replication.
25.
What kind of tasks do the enzymes play in?
Correct Answer
A. Aerobic respiration and pHotosynthesis
Explanation
Enzymes play a crucial role in both aerobic respiration and photosynthesis. In aerobic respiration, enzymes are involved in breaking down glucose molecules and releasing energy. They facilitate the various steps of the metabolic pathway, such as glycolysis, the Krebs cycle, and oxidative phosphorylation. In photosynthesis, enzymes are responsible for catalyzing the chemical reactions that convert light energy into chemical energy. They are involved in the synthesis of glucose and other organic molecules from carbon dioxide and water. Therefore, enzymes are essential for the proper functioning of both aerobic respiration and photosynthesis.
26.
Where are enzymes found in the membrane?
Correct Answer
A. Interal or peripHeral
Explanation
Enzymes can be found in both the integral and peripheral regions of the membrane. Integral enzymes are embedded within the lipid bilayer, whereas peripheral enzymes are attached to the surface of the membrane. This distribution allows enzymes to carry out their specific functions, such as catalyzing chemical reactions, either within the hydrophobic interior of the membrane or on the outer surface. The presence of enzymes in both regions contributes to the overall efficiency and regulation of cellular processes.
27.
What is the idea behind receptor proteins? ( What function)
Correct Answer
A. Building signaling molecules
Explanation
Receptor proteins are responsible for building signaling molecules. These molecules play a crucial role in cell communication and transmitting information between cells. Receptor proteins are located on the surface of cells and bind to specific molecules, such as hormones or neurotransmitters. This binding triggers a series of biochemical reactions within the cell, leading to various cellular responses. Therefore, receptor proteins are essential for the proper functioning of cells and the coordination of physiological processes.
28.
What is the membrane attachment for receptor proteins?
Correct Answer
C. Integral or peripHeral
Explanation
Receptor proteins can be attached to the cell membrane either through integral or peripheral attachment. Integral attachment refers to the protein being embedded within the lipid bilayer of the membrane, while peripheral attachment means that the protein is attached to the surface of the membrane. Therefore, receptor proteins can have either integral or peripheral membrane attachment depending on their specific structure and function.
29.
This is an recognition protein. What is its function?
Correct Answer
A. Identifier of cell type, individual, or species.
Explanation
This recognition protein functions as an identifier of cell type, individual, or species. It helps in distinguishing and recognizing different cells based on their specific characteristics.
30.
With passive transporter, do you requires ATP (energy) to transport the molecules or ions?
Correct Answer
A. No, you don't.
Explanation
Passive transporters do not require ATP (energy) to transport molecules or ions. Passive transport occurs down the concentration gradient, meaning that molecules or ions move from an area of higher concentration to an area of lower concentration without the need for energy. This process includes simple diffusion and facilitated diffusion, which both occur through passive transporters. Therefore, ATP is not needed for the transportation of molecules or ions in passive transport.
31.
Why does passive transporter need or not need energy?
Correct Answer
A. Doesn't ....Because it goes from high to low concentration
Explanation
Passive transporters do not require energy because they transport molecules or ions across a membrane along their concentration gradient, from an area of high concentration to an area of low concentration. This process is driven by the inherent kinetic energy of the molecules themselves and does not involve the use of ATP or any other external energy source.
32.
What is the active transporter?
Correct Answer
A. A protein that transports molecules or ions with the use of energy.
Explanation
The active transporter is a protein that transports molecules or ions with the use of energy. This means that it requires energy, usually in the form of ATP, to move molecules or ions across a cell membrane against their concentration gradient. Active transport is essential for maintaining proper ion concentrations and for the uptake of nutrients in cells. Unlike passive transport, which does not require energy, active transport allows cells to move substances against their natural flow, enabling them to perform vital functions in the body.
33.
Where to find the passive transporter?
Correct Answer
A. Integral
Explanation
Passive transporters are integral membrane proteins that facilitate the movement of molecules across the cell membrane without the need for energy. These transporters are embedded within the lipid bilayer of the membrane, making them an integral part of the membrane structure. Therefore, to find the passive transporter, one would need to look for it within the integral membrane proteins. Peripheral membrane proteins, on the other hand, are not embedded within the membrane and are typically found on the surface of the membrane.
34.
Ions and molecules tend to move from one region to another, in response to _________.
Correct Answer
gradients
Explanation
Ions and molecules tend to move from one region to another in response to gradients. Gradients refer to the differences in concentration, pressure, or electrical potential between two regions. These differences create a driving force that causes the ions and molecules to move in an attempt to equalize the gradient. This movement is known as diffusion or active transport, depending on the specific mechanism involved.
35.
Check some characteristics of selective permeability.
P.S: CM= cell membrane
Correct Answer(s)
A. Ability of CM to control which substances goes on or out of the cell.
B. Allow the cell to have a difference between internal and external extracellular fluid.
Explanation
Correction: Supplies the cell with nutrients, removes wastes, and maintains volume and pH.
36.
What is this?
Correct Answer(s)
selectively permeable membrane
Explanation
A selectively permeable membrane refers to a barrier that allows certain substances to pass through while restricting the passage of others. It is able to selectively control the movement of molecules based on their size, charge, or other properties. This type of membrane is commonly found in cells and plays a crucial role in maintaining homeostasis by regulating the flow of nutrients and waste products.
37.
Which one of these will move freely across the lipid bilayer?
Correct Answer(s)
B. O2
D. CO2
G. Testosterone
Explanation
Sucrose – no, it is polar.
O2 yes.
Na+ no, it is charged.
CO2. yes.
HCO3- no, it is charged..
DNA no, it is very large.
Testosterone yes, it is a small non polar molecule.
Lactose no, it is a disaccharide.
38.
What is a Concentration Gradient?
Correct Answer
A. A difference in the #\unit volume of ions or molecules of a substance between adjoining regions
Explanation
The correct answer is "A difference in the #\unit volume of ions or molecules of a substance between adjoining regions." This explanation accurately describes a concentration gradient as a difference in the number of ions or molecules of a substance between neighboring regions. This gradient represents a change in concentration, typically from an area of high concentration to an area of low concentration.
39.
Diffusion is the ___________ movement of ___ down a concentration gradient. ( seperate words by a space)
Correct Answer
net molecules
Explanation
Diffusion is the movement of net molecules down a concentration gradient. This means that molecules move from an area of higher concentration to an area of lower concentration. The term "net molecules" refers to the overall movement of molecules in a particular direction, taking into account both the molecules that are moving towards the higher concentration and those that are moving towards the lower concentration.
40.
A substance diffuses in a direction set by its _____ concentration gradient, not by the gradients of other solutes around it.
Correct Answer
own
Explanation
A substance diffuses in a direction set by its own concentration gradient, not by the gradients of other solutes around it. This means that the substance will move from an area of higher concentration to an area of lower concentration until equilibrium is reached. The concentration gradient refers to the difference in concentration between two areas, and it determines the direction and rate of diffusion. Therefore, the substance will only be influenced by its own concentration gradient, rather than the gradients of other solutes.
41.
What is this an example of?
Correct Answer
diffusion
Explanation
This is an example of diffusion, which is the process of particles spreading out and moving from an area of higher concentration to an area of lower concentration.
42.
Which law does this follow? ( Hint: Law of ____ )
Correct Answer
law of diffusion
Explanation
The given answer states that the law being referred to is the "law of diffusion." This suggests that the question is asking about a specific scientific principle or rule that governs the process of diffusion. The law of diffusion is a well-known scientific concept that describes the movement of particles from an area of high concentration to an area of low concentration. It states that the rate of diffusion is directly proportional to the concentration gradient and inversely proportional to the distance over which diffusion occurs. Therefore, the correct answer is the law of diffusion.
43.
The rate of diffusion depends on 5 factors, such as the steepness of the concentration gradient, which says that the rate of diffusion is higher with steeper gradients. Name the 4 others factors without capitals in alphabetical order and by seperating them with a space. ( Hint: One word each)
Correct Answer
charge pressure size temperature
Explanation
The rate of diffusion depends on four factors: charge, pressure, size, and temperature. These factors affect the movement of particles and determine how quickly they can diffuse from an area of higher concentration to an area of lower concentration.
44.
Which of these can diffuse freely across a lipid bilayer?
Correct Answer(s)
A. Gases
C. Nonpolar molecules
Explanation
Gases and nonpolar molecules can diffuse freely across a lipid bilayer because they are small and hydrophobic, allowing them to pass through the hydrophobic interior of the lipid bilayer. On the other hand, large polar molecules, large ions, and polysaccharides are hydrophilic and cannot easily pass through the lipid bilayer without the help of specific transport proteins or channels.
45.
If only certain things can pass freely across a lipid bilayer, how can the others pass? ( name one method; one-two words maximum)
Correct Answer(s)
passive transport
active transport
endocytosis
E.Exocytosis
Explanation
The different methods mentioned in the answer - passive transport, active transport, endocytosis, and exocytosis - allow for the passage of substances across a lipid bilayer. Passive transport refers to the movement of molecules down their concentration gradient without the need for energy. Active transport, on the other hand, requires energy and allows molecules to move against their concentration gradient. Endocytosis involves the engulfment of substances into the cell by forming a vesicle, while exocytosis involves the release of substances from the cell by fusing a vesicle with the cell membrane.
46.
What is endocytosis?
Correct Answer
A. Vesicle movement bringing substances in bulk into cell.
Explanation
Endocytosis is a process in which the cell takes in substances from the external environment by forming vesicles. These vesicles are formed by the plasma membrane folding inwards and engulfing the substances. This process allows the cell to bring in large molecules or particles that cannot pass through the membrane on their own. Therefore, the correct answer is "Vesicle movement bringing substances in bulk into cell."
47.
What is exocytosis?
Correct Answer
A. Vesicle movement ejects substances in bulk from cell.
Explanation
Exocytosis is a cellular process in which vesicles, small membrane-bound sacs, fuse with the cell membrane and release their contents outside of the cell. This process allows the cell to secrete substances such as hormones, neurotransmitters, and digestive enzymes. The correct answer states that vesicle movement ejects substances in bulk from the cell, which accurately describes the process of exocytosis.
48.
A gated passive transporter changes shape when a specific molecule binds to it.
Correct Answer
A. True
Explanation
A gated passive transporter refers to a type of protein that facilitates the movement of molecules across a cell membrane. In this case, the correct answer is true because a gated passive transporter undergoes a conformational change or shape change when a specific molecule binds to it. This change in shape allows the transporter to open up and allow the molecule to pass through the membrane. Therefore, the statement accurately describes the behavior of a gated passive transporter.
49.
Calcium pumps are active transporters that moves calcium ions across muscle cell membranes into......
Correct Answer
A. The sarcoplasmic reticulum
Explanation
Calcium pumps are active transporters that move calcium ions across muscle cell membranes. The sarcoplasmic reticulum is a specialized organelle found in muscle cells that stores and releases calcium ions. Therefore, it is the correct location for calcium ions to be transported to by calcium pumps. The bone apparatus and bones with deficiency in calcium are not involved in the transport of calcium ions by calcium pumps. The endoplasmic reticulum is a different organelle found in all eukaryotic cells, but it is not specifically involved in the transport of calcium ions by calcium pumps in muscle cells.
50.
After watching the first 2:35 minutes of the video, can you pick the right definition of a cotransporter?
http://www.youtube.com/watch?v=1RUnTEwO3Qg
Correct Answer
A. An active transport protein that moves two substances across a membrane at the same time.
Explanation
The correct definition of a cotransporter is an active transport protein that moves two substances across a membrane at the same time. This means that the cotransporter is able to transport two different substances simultaneously, in the same direction, across a membrane. This is different from the other options which either involve moving substances out of a membrane, at different times, or in different directions.