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WorksheetsScience - Chapter 8(2, 3)
Total questions: 141
Worksheet time: 2hrs 51mins
What is the function of cell membrane?
basic function of the cell membrane is to protect eh cell from its surroundings. Thus, it acts as a barrier.
The cell membrane is selectively permeable to certain substances and controls the movement of substances in and out of the cell
The cell membranes serve as barriers and gatekeepers, keeping out unwanted particles
a rigid layer of polysaccharides lying outside the plasma membrane of the cells of plants, fungi, and bacteria. In the algae and higher plants it consists mainly of cellulose.
Importance of the Cell Membrane: Structure
contains the cell contents
controls what enters and exits the cell
uses receptor proteins to identify materials and relay messages
recognizes foreign invaders and bars them from entry, or destroys them
is the barrier through which all material must pass
Importance of the Cell Membrane: Equilibrium
contains the cell contents
controls what enters and exits the cell
uses receptor proteins to identify materials and relay messages
recognizes foreign invaders and bars them from entry, or destroys them
is the barrier through which all material must pass
Importance of the Cell Membrane: Communication
contains the cell contents
controls what enters and exits the cell
uses receptor proteins to identify materials and relay messages
recognizes foreign invaders and bars them from entry, or destroys them
is the barrier through which all material must pass
Importance of the Cell Membrane: Protection & Defense
contains the cell contents
controls what enters and exits the cell
uses receptor proteins to identify materials and relay messages
recognizes foreign invaders and bars them from entry, or destroys them
is the barrier through which all material must pass
Importance of the Cell Membrane: Transportation
contains the cell contents
controls what enters and exits the cell
uses receptor proteins to identify materials and relay messages
recognizes foreign invaders and bars them from entry, or destroys them
is the barrier through which all material must pass
Since only certain substances are allowed to cross the membrane, movement across cell membrane is thereore called _________ _________.
(a)
Membranes can be classified in the following ways:
Impermeable
Permeable
Semi-permeable
Plasma membrane
Impermeable membrane
does not let anything pass through the membrane
allows all materials to pass through the membrane
allows some particles to pass through the membrane while excluding other particles
allow water pass through the membrane
permeable membrane
does not let anything pass through the membrane
allows all materials to pass through the membrane
allows some particles to pass through the membrane while excluding other particles
allow water pass through the membrane
semi-permeable membrane
does not let anything pass through the membrane
allows all materials to pass through the membrane
allows some particles to pass through the membrane while excluding other particles
allow water pass through the membrane
cell membranes are ____-_________, which means that some molecules can diffuse across the lipid bilayer but other cannot.
(a)
The cell membrane is composed of a type of fat called a ___________ and _______.
(a)
Phospholipids have a ___________ head and a ___________ tail
(a)
hydrophilic is
water loving
water hating
hydrophobic is
water loving
water hating
The phospholipids naturally arrange themselves in a bilayer(containing two layers), completely surrounding the cell, with the heads pointing outwards and tails pointing inwards.
True
Not False
Phospholipid: 'Phosopho' is
(a)
Phospholipid: 'lipid' is
(a)
Choose all the true about Phospholipid Bilayer
As the name implies, the membrane is made of two layers of fats that have phosphates attached
lipid tail points inward, away from water
Phosphate heads point outward, towards water
As the name implies, the membrane is made of two layers of proteins that have phosphates attached
membrane proteins embedded in the bilayer are same types of proteins
True
False
Various types of transport proteins carry large molecules and ions across the cell membrane
True
False
Different Proteins are embedded within the phospholipid bilayer but perform same functions for the cell.
True
False
The proteins enable different particles and chemicals to enter and leave the cell.
(a)
The proteins are specialized to receive certain chemicals such as hormones and initiate a chemical response in the cell
(a)
The proteins are like a cellular fingerprint, they enable white blood cells to recognize the difference between the cells o the body and foreign cells.
(a)
The _____ ______ _____ is the accepted model for the structure of the cell membrane
(a)
What is True about Fluid Mosaic Model
is the accepted model for the structure of the cell membrane
Fluid, because the membrane is flexible
Mosaic, because it is a collection of different substances that are held together.
Chemically a cell membrane is composed of four components: (1) Phospholipids (2) Proteins (3) Carbohydrates (4) Cholesterol
Particles Model of Matter.
Include any individual molecules of water, nutrients, waste, and gases traveling across the membrane
the particles of a substance are always moving
how far and how fast they move depends on:
- the relative concentration of that substance on either side of the membrane
- the state of the substance(solid, liquid or gas)
-Have a definite shape and volume
- do not flow or compress readily
- have the least amount of motion, mainly only vibrational
(a)
- take the shape of their container, but have a definite volume
- do not compress readily but flow readily
- have somevirational, rotational and translational motion
(a)
- take both the shape and the volume of their container
- highly compressible and flow readily
- have the highest amount of motion, mainly translational
(a)
All matter is made of particles, but they may be different in size and composition
True
True
The particles are constantly moving and move least in solids and most in gases. Heating particles make them move slower
False
True
The particles of matter are not attracted to one another but are bonded together.
False
True
Particles have spaces between them and are typically greatest in solids and smallest in gases.
False
false
(a) refers tot he amount of a substance dissolved in a solvent, usually water.
_____________ ________ exists when there is a difference in the amount of solute on either side of a membrane
(a)
Solutes naturally move Down the gradient, which means from an area of high concentration to an area of low concentration
true
False
the salt molecule in Salt Water is
Solvent
Solution
Solute
the Salt Water is
Solvent
Solution
Solute
the water molecule in Salt Water is
Solvent
Solution
Solute
According to the particle model, particles are always in motion
True
False
When the concentration of solute is equal on both sides of the membrane, equilibrium is reached
True
False
Even the equilibrium is reached does not mean that the particles stop; it means the net movement is zero.
true
False
The cell membrane is referred to as semi-permeable because it allows water pass through.
True
False
Passive transport
does not require energy
does require energy
Included: Diffusion, Facilitated Diffusion, Osmosis,
It included Exocytosis, Endocytosis
Passive Transport is molecules always move from ____ to ___ concentration area
(a)
Diffusion is
method of transport for molecules that are fat-soluble, or very small molecules like O2 and CO2
Because these molecules can dissolve or pass right through the barrier, their movement is not restricted by the cell membrane
Because these molecules can dissolve or pass right through the barrier, their movement is restricted by the cell membrane
method of transport for molecules that are water-soluble, or very small molecules like O2 and CO2
Facilitated Diffusion is like diffusion but only for large molecules like hlucose and charged ions
True
False
The word "facilitate" means "to assist"
true
False
Facilitated diffusion
it is still a form of passive transport - like floating downstream on a raft
it not a form of passive transport
facilitated diffusion is for substances that are water soluble, so they can't pass through the lipid portion of the membrane
facilitated diffusion is for substances that are water soluble, so they can pass through the lipid portion of the membrane
Channel Protein
shaped like tubes
shaped like a ball
form tunnels through the membrane through which the water0soluble molecule can pass(out or in)
form tunnels through the membrane through which the fat-soluble molecule can pass(out or in)
Carrier protein
attach to larger molecules that can't fit though the protein channels
the protein will attach to the molecule on the outside of the cell, then roll over to deposit the molecule inside the cell
the protein will attach to the molecule on the outside of the cell, then roll over to deposit the molecule inside the cell
attach to larger molecules that can't fit though the protein channels
skin is semi-permeable, the water won't going to your body because there is fats under the skin.
True
False
Osmosis is similar to difussion, except deals solely with the movement of (a) molecules
Osmosis occurs when there is a solute concentration difference, but the membrane is ___ _________ to the solute.
(a)
because the solute is not free to move, particles of water will move until the relative concentrations are (a) on either side of the membrane
When there is a movement of water, the volume of solution on either side of the membrane changes.
- this can have an adverse effect on the cell
True
False
What are 3 types of Osmosis?
Isotonic Solution
Hypotonic Solution
Hypertonic Solution
Facilitated Diffusion
________ ________: concentration inside and outside the cell is equal
(a)
Isotonic solution: when a cell is placed in an isotonic solution, there is net movement of water in and out of the cell.
True
False
Isotonic Solution: net-0 means water is not flowing
True
False
Facts about Isotonic solution.
Water is flowing in and out in equal amounts
animal cells will appear normal
plant cells will appear slightly limp due to a lack of turgor pressure
plant cells will appear normal
_________ ________: the concentration of solutes outside the cell is lower than inside the cell
(a)
What is true about hypotonic?
hypo = "lower"
(e.g. hypothermia = low body temperature)
in an effort to find equilibrium, water will flow from the extracellular fluid (ECF) into the cell
the cell becomes bloated and "overfull" and can eventually rupture(called plasmolysis)
Hypo = "higher"
(e.g. hypoactive = highenergy levels)
the cell becomes bloated and "overfull" and can eventually rupture(called (a) )
Facts about Hypotonic Solution.
Water is flowing into the cell faster than it is flowing out
animal cells will appear swollen, and may bust
plant cells will appear turgid, and the plant will appear healthy
Water is flowing into the cell slowerr than it is flowing out
__________ ________: the concentration of solutes outside the cell is higher than inside the cell
(a)
What describes Hypertonic?
Hyper = "higher"
(e.g. hyperactive = high energy levels)
in an effort find equilibrium, water will flowing from cell into the ECF
The cell becomes shriveled and dried up
What is the facts about Hypertonic?
water is flowing out of the cell faster than it is flowing in
animal cells will appear shriveled, and may die
plant cells membrane will pull away from the rigid cell wall
as it loses turgidity, the plant will appear wilted and limp
Osmosis is what keeps plant cells plump and full of water so that the plants do not look wilted.
True
False
Water pressure outside a plant cell pushes against the rigid cell wall causing turgor pressure.
True
False
The walls of plant cells are able to withstand a great deal of turgor pressure
True
False
If an animal cell takes in too much water by osmosis, it will burst(lysis)
True
False
______ _________ move molecules against the concentration gradient
(a)
It is called active transport because it requires extra work and energy by the cell
- like swimming upstream, against the current
- It is accomplished by the channel proteins, which pump the molecules from an area of high to low concentration.
True
False
What does ATP stand for?
(a)
Active Transport always requires the cell membrane. Energy(ADP) is used
True
False
The energy that is supplied to the proteins to carry out this task(active transport) is produced in the (a) .
the energy in ATP is created through the process of ________ ___________
(a)
The energy created through the process of cellular respiration is packaged into a substance called ATP
True
False
Active transport mechanisms involving a transport protein are called " (a) "
Sodium-Potassium pump
Correct
Not Wrong
Which is the type of protein responsible for active transport
Active transport protein
carrier protein
channel protein
transport protein
Even with the help of proteins, some molecules are simply too big to fit through the membrane. Instead, the cell use a process called (a)
exocytosis: cells engulf large particles by extending their cytoplasm around the particle
True
False
Neither
Endocytosis
This process is used by cells to take in substances, in which the membrane folds in, encloses the item in a sphere, then pinches off a vesicle.
this ingested particle is trapped within a punch or vacuole, inside the cytoplasm
Enzymes from the lysosomes are often used to digest the large particle absorbed
Phagocytosis and Pinocytosis are two forms of Endocytosis
Select all the answer that is true
Phagocytosis is endocytosis of solids
pinocytosis is endocytosis of liquids
phagocytosis is endocytosis of liquids
pinocytosis is endocytosis of solids
________ ________ ___________ - particles attach to receptors and stimulate endocytosis
(a)
Exocytosis
The reverse of endocytosis(exo = in)
used when a cell needs to rid itself of a large waste product
a vesicle formed by the Golgi apparatus surrounds the molecule and transports it to the membrane
the vesicle merges with the membrane, releasing the molecule into the ECF
(a) : This process expels compounds to the surroundings by fusing the membrane of a vesicle or vacuole with the membrane, and then releasing the contents into the cell's environment.
Exocytosis:
Large molecules within the cell are transported to the external environment
Useful materials, like transmitter chemicals from nerve cells, are also released(secreted)
Small vesicles break off the Golgi Apparatus and move towards the cell membrane
it only can transfer waste
Read all the text below
Active Transport: transport anything that is going versus the gradient
Osmosis does require a membrane protein
Active Transport requires ATP and is going against the gradient
Diffusion transport small and fat-soluble molecules
Knowledge about the cell membrane has prompted the industrial use of synthetics to mimic natural functions. This area of research and development is known as ________ ____________.
(a)
The molecules associated with the cell membrane on the surface of the cell are important for many cell activities. Some proteins, called ___________ ________, are embedded in the cell membrane, but stick out into the cellès surroundings.
(a)
In order for some substances to enter the cell, they must dock at these receptor molecules first(Recognition Proteins)
- Like a lock-and-key mechanism
if the shape of the molecule does not fit with the receptor, it will not gain access to the cell
true
True
________ ________ may bind specifically with certain molecules to bring them into he cell by endocytosis. Some of these proteins have sugar groups attached to them that make the binding specific and allow the cell to identify a particular bacteria or virus.
(a)
Choose all the true statements
the pharmaceutical industry is interested in these receptor molecules because the medication cannot work unless it can get into the cell
the closer the match between the shape of the medication and the receptor molecule, the less targeted the medication can be, and therefore the more effective
for example, new pain relievers that treat migraines instead of providing overall pain relief
for example, new pain relievers that treat migraines instead of providing overall pain relief
Select all the true statement
some viruses, like HIV, gain access to the cell by mimicking the shape of a harmless substance
- they bind to the receptor proteins and "trick" it into gaining access to the cell
by discovering the shape of the virus's protein coat, researchers can produce medication that binds to the virus and blocks it from entering the cell.
- the reason HIV is so hard to treat is that its protein coat is constantly mutating and changing shape
- new research looks at blocking off the receptor proteins on the human cells to cover the "keyhole"
common treatments for cancer do not target only the cancerous cells but target healthy cells as well
new research looks at ways to identify only the cancerous cells and develop drugs specific to the protein coat of the cancerous cells
this would also provide the immune system with a way of recognizing and attacking cancerous cells
a liposome is a form of medication that surrounds a fluid0filled sac with a phospholipid bilayer
True
False
liposomes: this mimics a vesicle produced by the cell - the medicine is able to dissolve directly through the cell membrane
true
False
Liposome medication can be introduced intravenously and are able to deliver the medication much quicker
True
False
A
(a)
B
(a)
C
(a)
D
(a)
E
(a)
(a) are chemical messages produced by one part of the body that act on another part
(a) is produced by the pancreas, and acts on all body cells to tell them to pick up glucose for cellular respiration
Diabetics are able to produce insulin and it is properly used by the body
- by understanding how hormones are transported and used by cells, diabetes treatments are improved
- synthetic insulin can now be produced that mimics the shape of human insulin, as an alternative to pig or cow insulin
True
False
(a) treatments are used by patients who have malfunctioning kidneys
What is two types of Dialysis
Peritoneal Dialysis
Hemodialysis
Peritoneal Dialysis
Homodialysis
Peritonal Dialysis
Hemodialysis
Preitoneal Dialysis
Hemodialysis
Peritoneal Dialysis
a catheter is inserted into the abdominal cavity
a sterile fluid containing water, glucose, and electrolytes is pumped into the cavity
the concentration of waste in the blood is much higher than in the dialysate fluid
- nutrients from the fluid diffuse into the blood, and waste diffuses out
- the "dirty" fluid is pumped back out of the body and disposed of
a patient's blood is physically removed from the body, cleaned using dialysate fluid, and returned to the body
this procedure is much more invasive and requires the patient to be in the hospital
Hemodialysis
a catheter is inserted into the abdominal cavity
a sterile fluid containing water, glucose, and electrolytes is pumped into the cavity
the concentration of waste in the blood is much higher than in the dialysate fluid
- nutrients from the fluid diffuse into the blood, and waste diffuses out
- the "dirty" fluid is pumped back out of the body and disposed of
a patient's blood is physically removed from the body, cleaned using dialysate fluid, and returned to the body
this procedure is much more invasive and requires the patient to be in the hospital
insulin is a small protein produced in the (a)
Choose all the true statements
Specialized cells in the pancreas have channels that detect glucose(so-called blood sugar) in the bloodstream. This initiates the excretion of insulin into the blood
Insulin binds to receptor proteins of tissues including liver, muscle, and fat. This binding stimulates the rate of movement of glucose into the cells through facilitated diffusion using a channel protein.
Glucose is then used either directly to produce energy or stored as a future source of energy as glycogen in the liver, fat in the fat tissue, and protein in the muscle.
In humans, cells form a membrane called the (a) , which lines the abdominal cavity.
(a) is the process of removing salt from sea water in order to make it suitable for drinking.
- Seawater in Antarctica is very cold, so it is first warmed slightly and then pumped through a 25-um filter to eliminate coarse materials. The filter contains layers of anthracite coal, sand, garnet, and limestone. The water is pumped through progressively smaller filters that allow only smaller and smaller particles to pass through.
- The process is referred to as reverse osmosis(RO) because the water moves from a low water concentration (high concentration of solute) to a high water concentration(low concentration of solute) and therefore requires the force of pressure of a pump
RO makes use of semi-permeable membranes that allow the water to be forced through but filter out other molecules or micro-organisms of progressively smaller and smaller sie. As this process proceeds, the rejected materials continue to increase in solute concentration, requiring more force to push the water through. Reverse osmosis is affected by charged particles, like salts, so that the larger the molecule and the greater the charge on it, the less likely it will be to move through the membrane. "Backwash" from the filtration process helps to keep the filter clean. Following the RO process, the pH levels of the water are adjusted and chlorine is added to kill any bacteria still present. RO is an efficient, but expensive, method of desalinating and purifying water in Antarctica and other places of the world where freshwater is in extremely short supply. RO systems are now available for home water purification.
I read the statement
I didn't read the statement
I did not read the statement
I will read the statement later
Cell wall is made up of (a)
Glycogen is a storage form of energy in animals. It is a branched polymer composed of glucose units. It is more highly branched than amylopectin. Cellulose is a structural polymer of glucose units found in plants.
true
True
true
true
The vacuole is also a type of vesicles. Plant cells contain a large, central vacuole, storing mostly water and nutrients. The main difference between vesicles and vacuole is that vesicle is designed to store different types of molecules whereas vacuole is a type of vesicle, mostly storing water.
True
wrong
Vesicles and vacuoles are membrane-bound sacs that function in storage and transport. Vacuoles are somewhat larger than vesicles, and the membrane of a vacuole does not fuse with the membranes of other cellular components. Vesicles can fuse with other membranes within the cell system
True
False
plant cell store their energy in the form of (a)
animal cells store energy in the form of (a)
in cells,surface area would be the size of the ____ ________
(a)
in cells, volume is how much "stuff" (organelles, cytoplasm, etc) is in a cell.
True
False
(a) can easily enter a cell by crossing the cell membrane
Once the nutrients are in the cell they move fast through the cytoplasm
False
True
in order to survive, the organelles in the cell need the nutrients slow, so the cell won't burst.
False
True
Choose all the true statements
lots of surface area: to take in as many nutrients as possible across its cell membrane
little of surface area: to take in as many nutrients as possible across its cell membrane
little volume: so the organelles are close by
lots volume: so the organelles are close by
a (a) SA/V means efficient transfer of materials
a (a) SA/V means poor or inefficient transfer of materials
The (a) the ratio the more efficient cell transport will be
what is the surface area to volume ratio of a cube that has side lengths of 2.5cm?
__._cm² : __.___cm³
(a)
A larger cell has a larger surface area but also a larger volume
- though it can take in more nutrients, it also has higher nutritional needs
- though it can get rid of waste faster it also produced more waste
to predict which cell is favored for survival, you have to look at the surface area to volume ratio
True
False
A smaller cell will have a better chance of survival due to a higher surface area to volume ratio
- however, in multicellular organisms, some cells perform specialized functions that require them to take on a larger size
True
False
Why can animals grow so large?
in the respiratory system, the total surface area for gas exchange is increased by the branching of the bronchioles, ending in sacs called alveoli, that exchange oxygen and carbon dioxide with numerous blood vessels called capillaries.
In the digestive system, the lining of the digestive tract(the small intestine) has numerous fingers like projections called villi that increase the surface area for uptake of nutrients. Capillaries extend within each villus, reducing the total distance that materials need to travel to diffuse into the circulatory system
in the respiratory system, the total surface area for gas exchange is increased by the branching of the bronchioles, ending in sacs called alveoli, that exchange oxygen and carbon dioxide with numerous blood vessels called capillaries.
In the digestive system, the lining of the digestive tract(the small intestine) has numerous fingers like projections called villi that increase the surface area for uptake of nutrients. Capillaries extend within each villus, reducing the total distance that materials need to travel to diffuse into the circulatory system
why can plants grow so large?
- Vascular plants (not all plants) contain tissue called xylem and phloem (called vascular tissue) that transport water and sap throughout the plant.
- They act as a circulatory system by bringing the materials needed by the cells close to the cell so that exchange via diffusion can happen faster.
- Plants such as mosses do not have vascular tissue, hence they are limited in size.
True
True
