College Biology 4,5,6,
Uniporters
transport a single type of molecule(pg. 100)
Antiporters
transport two molecules in the opposite direction(pg.100)
Symporters
transport two molecules in the same direction(pg. 100)
turgor pressure
(pg.99) The internal pressure inside a plant cell, resulting from osmotic intake of water, that presses its cell membrane tightly against the cell wall, making the cell rigid. Also known as hydrostatic pressure.
Cell Theory
1. All organisms are composed of one or more cells. 2. Cells are the smallest living things the basic units of organization of all organisms 3. Cells arise only by division of a previously existing cell.
What chemical property characterizes the interior of the phospholipid bilayer? A. hydrophobic B. hydrophilic C. polar D. saturated
A
which of the following is NOT a mechanism of bringing material into a cell? A. Exocytosis B.Endocytosis C.Pinocytosis D.Phagocytosis
A
Why are cells sized the way they are?
A cell's size is primarily due to the reasons related to the diffusion fo substances in and out of them. 1. Surface Area 2. Temperature 3. Concentration 4. Distance
Central Vacuole
A large sac which stores mainly water, proteins, pigments and waste materials.
What are the advantages of a cells size?
A large surface area to volume ratio.
Transporter
A membrane protein that binds a solute and undergoes a conformational change to allow the movement of the solute across a membrane.
Nuclear Envelope
A membrane surrounding a Eukaryotic cell's DNA. Two phospholipid bi-layer
Plasma Membrane
A membrane which encloses a cell and separates its contents from its surroundings.
Fluid mosaic model
A model that describes the structure of cell membranes. In this model, a flexible layer made of lipid molecules is interspersed with large protein molecules that act as channels through which other molecules enter and leave the cell
Which of the following is not a function of the Golgi apparatus? A) Synthesizing protein B) Packaging protein C) Sorting protein D) Collecting protein E) All of these are functions of the Golgi apparatus
A) Synthesizing protein
If a plant cell is put in an environment which is hypertonic to the cytoplasm, water will A) diffuse into the cell less than out of the cell. B) diffuse out of the cell less than into the cell. C) diffuse into and out of the cell at the same rates D) not diffuse either in or out of the cell. E) dissolve into the plasma membrane.
A) diffuse into the cell less than out of the cell.
Transmembrane domain
These domains are composed of hydrophobic amino acids usually arranged into helices. (pg.95)
Cation
A positively charged ion.
Aquaporin
A protein channel that allows the rapid diffusion of water into and out of certain cells
Peripheral protein
A protein that temporarily adheres to the biological membrane, either to the lipid bilayer or to integral proteins by a combination of hydrophobic, electrostatic, and other non-covalent interactions.
Cell Wall
A rigid wall that helps to support and protect the cell.
Thylakoid
A single disk that that helps to capture light.
Hypotonic
A solution with a lower concentration of solutes than the cell. A cell in a ___________ solution tends to take in water by osmosis
Grana
A stack of membranes in the chloroplast
Transmembrane protein
A type of membrane protein spanning the entirety of the biological membrane to which it is permanently attached. That is, transmembrane proteins span from one side of a membrane through to the other side of the membrane.
Most enzymes are globular proteins with one or more active sites where specific substrates can bind, forming a(n) A) Enzyme-substrate complex. B) Catalyst. C) Product. D) High-energy intermediate. E) Stable intermediate.
A) Enzyme-substrate complex.
Which is the most likely role for a glycoprotein in a cell's membrane? A) It serves for cell-to-cell recognition. B) It stabilizes the inner face of the membrane. C) They provide passage for substances and information to the cell's interior. D) It is a member of the flexible matrix which increases the membrane's ability to act as a barrier. E) All of the above are equally likely roles.
A) It serves for cell-to-cell recognition.
The total of all chemical reactions carried out by an organism is A) Metabolism. B) The reaction budget. C) The reactant/product ratio. D) Its energy budget. E) Feedback inhibition.
A) Metabolism.
Select the membrane molecule that is made up of a polar region with two nonpolar fatty acid tails. A) Phospholipids B) Cell surface proteins C) Transmembrane proteins D) Carbohydrate chains E) Glycolipids
A) Phospholipids
A paramecium is a single-celled organism with a structure called the "contractile vacuole" which fills with water and contracts to release water from the cell to maintain the correct osmotic balance. If a paramecium is moved from a solution of dilute salt to distilled water, which of the following effects will be seen? A) The contractile vacuole will pulse more quickly. B) The contractile vacuole will pulse more slowly. C) There will be no change in the activity of the contractile vacuole. D) The cell will enlarge. E) The cell will shrink.
A) The contractile vacuole will pulse more quickly.
Which statement about membrane proteins is NOT true? A) They all extend from one side of the membrane to the other. B) Some serve as channels for ions to cross the membrane. C) Many are free to migrate laterally within the membrane. D) Their position in the membrane is determined by their tertiary structure. E) Some play roles in cell identification.
A) They all extend from one side of the membrane to the other.
True or False: A major function of chloroplasts is to convert the energy of sunlight into carbohydrates. A) True B) False
A) True
True or False: Mitochondria and chloroplasts are organelles in eukaryotes that have properties of prokaryotes, suggesting an ancient symbiotic origin. A) True B) False
A) True
Substrate concentration A) affects reaction rate. B) increases spontaneously during an exergonic reaction. C) can be increased indefinitely and the reaction rate will also increase indefinitely. D) can be lowered to increase the reaction rate. E) can be increased to decrease the reaction rate
A) affects reaction rate.
Plasmodesmata and gap junctions A) allow small molecules and ions to pass rapidly between cells. B) are both membrane lined channels. C) are channels about 1 mm in diameter. D) are present are in small numbers in a cell. E) are involved in cell recognition in signaling.
A) allow small molecules and ions to pass rapidly between cells.
A difference between passive transport and active transport is A) they have different energy requirements. B) the use of proteins as carriers. C) the way they carry solutes in different directions. D) that active transport is only utilized when the cell is actively dividing. E) they differ in their dependence on the solubility of the solute in lipid.
A) they have different energy requirements.
Cytoskeleton (3)
Actin Microtubules Intermediate filaments
The function of a carrier
Actively or passively transport molecules across the membrane.
Ion channels
Allow the passage of ions Gated channels - open or close in response to stimulus (chemical or electrical)
Nucleoid
An area inside of a prokaryotic cell where its DNA exists.
Fatty acid desaturases
An enzyme that removes two hydrogen atoms from a fatty acid, creating a carbon/carbon double bond.
The function of clathrins
Anchors certain proteins to specific sites, including the exterior plasma membrane in receptor cells mediated in endocytosis.
Chromosomes
Are DNA which is tightly wound around proteins and packages into compact units.
What are the 3 conditions that determine direction?
Relative concentration on either side of membrane Voltage differences across membrane Gated channels - channel open or closed
The movement of water across the membrane is dependent on? A. The solvent concentration B. The solute concentration C. The presences of carrier proteins D. Membrane potential
B
Which of the following is NOT a factor affecting enzyme activity? A) Temperature B) Concentration of reactants C) pH D) Inhibitors and activators E) Enzyme cofactors
B) Concentration of reactants
Substance A is allowed to readily travel across the cell membrane following the concentration gradients. This is called A) Diffusion. B) Facilitated diffusion. C) Osmosis. D) Bulk transport. E) Active transport.
B) Facilitated diffusion.
How might a membrane improve the efficiency of an enzymatic pathway? A) It creates order in what is otherwise a highly disordered cytoplasm. B) It can orient active sites of enzymes in the same pathway towards a chamber containing the reactants. C) It increases the amount of entropy in the reaction, giving the overall reaction a more negative G value. D) It decreases the activation energy of all the enzymatic catalysts by an equal amount. E) None of the above are correct.
B) It can orient active sites of enzymes in the same pathway towards a chamber containing the reactants.
What property must a molecule have to cross a membrane and initiate a response? A) It must have hydrophilic properties B) It must have hydrophobic properties C) It must have sulfur in its structure D) It must degrade DNA E) It needs to have many alpha helices
B) It must have hydrophobic properties
Which of the following is the most comprehensive definition of "energy"? A) The ability to make high-energy compounds. B) The capacity to do work. C) Changes in the amount of heat in a system. D) Potential power. E) Movement of molecules within a system.
B) The capacity to do work.
Why are cell membranes said to be fluid? A) The covalently bound molecules exist as a liquid at biological temperatures. B) The lipid bilayers are not bonded to one another, allowing movement like a fluid. C) The molecules allow fluids to pass readily across the membrane. D) The membrane exists as a fatty acid layer which is stabilized by hydrophobic interactions with water. E) Proteins embedded within the membrane force the structure to expand and contract giving it fluid qualities.
B) The lipid bilayers are not bonded to one another, allowing movement like a fluid.
Why is the structure of the Singer and Nicholson membrane model called the "fluid mosaic model"? A) The membrane exists as a liquid at regular body temperature, but has small regions of solidity to support it. B) The phospholipids can move laterally within the plane of the membrane, and proteins are embedded within it to give it special functions. C) Proteins provide flexibility within the rigid phospholipid bilayer. D) It refers to the liquid lipid sheet which was "painted" with a stabilizing mosaic of protein on its outer and inner surfaces. E) All of the above are valid reasons for the name of the model.
B) The phospholipids can move laterally within the plane of the membrane, and proteins are embedded within it to give it special functions.
The amount of energy available to break and form chemical bonds is referred to as a molecule's A) entropy. B) free energy. C) activation energy. D) catalyst. E) reaction energy.
B) free energy.
One organelle, called the _______________, contains enzymes that digest worn out parts of cells. A) ribosome B) lysosome C) vacuoles D) endoplasmic reticulum E) centriole
B) lysosome
How does the energy of sunlight enter into biological systems? A) It decreases the kinetic energy of the molecules it contacts. B) It oxidizes organic molecules in a redox reaction. C) It facilitates the conversion of simple molecules into complex ones. D) It breaks the bonds between carbon and hydrogen. E) It is converted from potential to kinetic energy during photosynthesis.
C) It facilitates the conversion of simple molecules into complex ones. C) It facilitates the conversion of simple molecules into complex ones.
The three principle fibers of the cytoskeleton are: A) Actin, myosin, and centrioles B) Actin, tubulin, and myosin C) Microtubules, microfilaments, and intermediate filaments D) Proteins, phospholipids, and polysaccharides E) Vesicles, connector molecules, and molecular motors
C) Microtubules, microfilaments, and intermediate filaments
The primary constituents of biological membranes are A) Triglyceride bilayers. B) Saccharides. C) Phospholipid bilayers. D) Glycoproteins. E) Peptidoglycans.
C) Phospholipid bilayers.
Which statement about enzymes is NOT true? A) They act to speed up a biochemical reaction. B) They are made up of RNA or protein. C) They act to raise the activation energy of a reaction. D) They are sensitive to heat. E) They are sensitive to pH.
C) They act to raise the activation energy of a reaction.
How do catalysts affect the rate of a reaction? A) They slow down the reactions because every reactant has to first join with a catalyst before products are created. B) They have no effect on reaction rate because without them, the reaction would never occur anyway. C) They increase the rate of reaction because they lower the activation energy. D) They slow down the reactions due to the loss of free energy. E) They increase the rate of the reaction by increasing the reactants free energy.
C) They increase the rate of reaction because they lower the activation energy.
What feature of the fatty acids cause phospholipids to aggregate spontaneously? A) Fatty acids form ionic bonds with adjacent molecules in the plane of the membrane. B) Fatty acids have intense Van Der Waals interactions with other fatty acids. C) Water molecules form hydrogen bonds with the polar "heads" of the phospholipid molecule. D) Fatty acids' ester linkages to glycerol provide hydrogen bonding just under the polar "head". E) They attract half the amount of water that the polar heads do, thereby giving them room to "stick together".
C) Water molecules form hydrogen bonds with the polar "heads" of the phospholipid molecule.
Membrane phospholipids A) are dissolved in the water of the cell. B) are totally surrounded by membrane proteins in a "sandwich." C) encircle the cell in a double layer. D) have their nonpolar regions facing the cell exterior. E) have phosphates ionically bound to polar lipids.
C) encircle the cell in a double layer.
Oxidative metabolism takes place in the ___________________ of the cell. A) Golgi complex B) endoplasmic reticulum C) mitochondria D) nucleus E) peroxisome
C) mitochondria
Coenzymes differ from enzymes in that coenzymes are A) active only outside the cell. B) polymers of amino acids. C) non-protein organic molecules. D) higher in energy state. E) specific for a single reaction.
C) non-protein organic molecules.
Carrier proteins
Can help transport both ions and other solutes, such as some sugars and amino acids Requires a concentration difference across the membrane Must bind to the molecule they transport Saturation - rate of transport limited by number of transporters
Facilitated diffusion
Carrier-assisted diffusion of molecules across a cellular membrane through specific channels from a region of higher concentration to one of lower concentration; the process is driven by the concentration gradient and does not require cellular energy from ATP.
What are transmembrane proteins made of?
Carriers, Channels, and receptors
Enzymes
Cells carry out many chemical reactions on the interior surface of the plasma membrane, using enzymes attached to the membrane.
Cell- to- cell adhesion proteins
Cells use proteins to glue themselves to one another, some are temporary and others can be permanent.
Selectively permeable
Condition in which a membrane is permeable to some substances but not to others.
Stroma
Cytoplasm inside of the chloroplast.
Osmosis
Cytoplasm of the cell is an aqueous solution Water is solvent Dissolved substances are solutes (ions, sugars, amino acids) Osmosis - net diffusion of water across a membrane toward a higher solute concentration(pg. 98)
If a cell is in an isotonic environment then? A. The cell will gain water and burst B. No water will move across the membrane C. The cell will lose water and shrink D.osmosi still occurs, but there is no net gain or loss of cell volume.
D
The fluid mosaic model of the membrane describes the membrane as? A. containing a significant quantity of water in the interior. B. Composed of fluid phospholipids on the outside and proteins on the inside. C. Composed of proteins on the outside and fluid phospholipids on the inside. D. Made out of proteins that can move freely.
D
The specific function of the membrane within a cell is determined by the? A.degree of saturation of the fatty acids within the bilayer B.location of the membrane within the cell C. presence of the lipid rafts and cholesterol D. type and number membrane proteins
D
The transmembrane domain of an integral membrane protein A. is composed of hydrophobic amino acids B. often forms a helical structure C. can cross the membrane multiple times. D. All of the above
D
Endocytosis is an example of A) Diffusion. B) Facilitated diffusion. C) Osmosis. D) Bulk transport. E) Active transport.
D) Bulk transport.
Which statement about endocytosis is NOT true? A) Endocytosis brings large macromolecules, large particles, small molecules and small cells into the eukaryotic cell. B) In endocytosis, the plasma membrane invaginates around materials from the environment, forming a small pocket. C) Phagocytosis is a type of endocytosis. D) Endocytosis involves the discharge of material from vesicles at the cell surface. E) Pinocytosis is a form of endocytosis that brings in small dissolved substance or fluids.
D) Endocytosis involves the discharge of material from vesicles at the cell surface.
Which of these statements best describes the First Law of Thermodynamics? A) All of the energy in the universe is going from a more ordered state to a less ordered state. B) Energy in a closed system can be destroyed. C) Entropy is always increasing. D) Energy is never really lost; it just goes from one state to another. E) As energy is used, more of it is converted into heat.
D) Energy is never really lost; it just goes from one state to another.
Which statement about feedback inhibition of enzymes is not true? A) It is exerted through allosteric effects. B) It is directed at the enzyme that catalyzes the first committed step in a branch of a pathway. C) It affects the rate of reaction, not the concentration of enzyme. D) It acts very slowly. E) It is an example of negative feedback.
D) It acts very slowly.
Which of the following statements concerning enzymes is true? A) Molecular structure does not determine enzyme function. B) Binding at the active site allows the enzyme to always retain its shape. C) Enzymes function on their own; they never need cofactors or any sort of regulation. D) Some enzymes change shape when substrate binds to them. E) Non-competitive inhibitors compete for the active site.
D) Some enzymes change shape when substrate binds to them.
Which of the following statements accurately describes the nature of the cell membrane? A) The molecules are covalently linked forming a solid structure. B) The molecules form a single layer with polar regions facing towards the interior part of the cell and the hydrophilic regions facing the exterior. C) Ionically bonded sugars form a double layer that is semi-permeable. D) The molecules form a double layer with polar regions facing the interior and the exterior of the cell while the hydrophobic regions orient towards each other. E) A single layer of molecules is oriented with polar regions oriented toward the interior and exterior of the cell.
D) The molecules form a double layer with polar regions facing the interior and the exterior of the cell while the hydrophobic regions orient towards each other.
Which of the following statements is TRUE about enzymes? A) They are composed of carbohydrates. B) There are very few different enzymes but each can catalyze many different reactions. C) Enzyme catalyzed reactions are the minority in biological systems because, under biological conditions, most chemical reactions are spontaneous. D) There are many different enzymes known, each catalyzing one or more specific chemical reactions. E) Cells use enzymes to increase activation energies.
D) There are many different enzymes known, each catalyzing one or more specific chemical reactions.
The phospholipid bilayer A) is readily permeable to large, polar molecules. B) is entirely hydrophobic. C) is entirely hydrophilic. D) acts as a scaffold for various cell-surface markers. E) is made up of polymerized amino acids.
D) acts as a scaffold for various cell-surface markers.
Eukaryotes must organize their microtubules, especially during cell division. What region is responsible for serving as the microtubule-organizing center for ALL eukaryotic cells? A) the nuclear membrane B) pericentriolar material C) centrioles D) centrosomes E) centromeres
D) centrosomes
The nucleoplasm is connected to the cytoplasm through the action of: A) nucleoli B) chromatin C) chromosomes D) nuclear pores E) endoplasmic reticulum
D) nuclear pores
Concentration Gradient
Differences in solute concentrations across membranes. Usually energy is required to maintain concentration gradients.
Simple Diffusion
Diffusion of molecules through the cell membrane
Sodium-potassium (Na+-K+) pump
Direct use of ATP for active transport Uses an antiporter to move 3 Na+ out of the cell and 2 K+ into the cell Against their concentration gradient ATP energy is used to change the conformation of the carrier protein Affinity of the carrier protein for either Na+ or K+ changes so the ions can be carried across the membrane(pg.101)
How structure relates to functions.
Diverse functions arise from the diverse structures of membrane proteins Have common structural features related to their role as membrane proteins Peripheral proteins Anchoring molecules attach membrane protein to surface
The name given to the accepted description of the cell membrane is the A) "soap bubble" model B) "lipid fluid" model C) "membrane cross-linkage" model D) "protein interchange" model E) "fluid mosaic" model
E) "fluid mosaic" model
The chief energy currency all cells use is a molecule called A) DNA. B) Enzyme. C) Ribosome. D) Activator. E) ATP.
E) ATP.
Which of the following is MOST likely to affect the efficiency (activity) of an enzymatic reaction? A) Changes in temperature B) Changes in pH C) Absence of cofactors such as metal ions in the active site D) Presence of inhibitors E) All of the above affect enzyme activity
E) All of the above affect enzyme activity
The nucleus of the eukaryotic cell functions: A) as the command center for the cell B) to store the cell's hereditary information C) to house the nucleolus D) to selectively allow certain molecules access to the genetic material and to exit to the cytoplasm E) All of the choices are correct.
E) All of the choices are correct.
Which statement about thermodynamics is NOT true? A) Free energy is given off in an exergonic reaction. B) Free energy can be used to do work. C) A spontaneous reaction is exergonic. D) Free energy tends always to decrease. E) Entropy tends always to decrease.
E) Entropy tends always to decrease.
Which of the following will happen to a coupled transport system when ATP is exhausted? A) Pinocytosis is possible in leukocytes (white blood cells), while phagocytosis is not. B) Pinocytosis occurs in eukaryotes, while phagocytosis occurs in prokaryotes. C) Pinocytosis is more specific in the substances it accumulates than phagocytosis. D) Phagocytosis is driven by active transport, while pinocytosis uses diffusion. E) Pinocytosis is primarily involved with engulfing nutrients in fluid droplets.
E) Pinocytosis is primarily involved with engulfing nutrients in fluid droplets.
In a chemical reaction, if the reactants have less free energy than the products, A) The reaction will tend to be spontaneous. B) The reaction will give off energy. C) There is no need for activation energy. D) Catalysts will not affect the reaction. E) The reaction will require the input of energy to drive the creation of products.
E) The reaction will require the input of energy to drive the creation of products.
Direct and indirect active transport both A) generate ATP. B) are based on passive movement of sodium ions. C) include the passive movement of glucose molecules. D) use ATP directly. E) can move solutes against their concentration gradients.
E) can move solutes against their concentration gradients.
______________ function in the collection, packaging, and distribution of molecules made in the cell. A) ribosomes; nucleolus B) Golgi complex; endoplasmic reticulum C) peroxisomes; lysosomes D) nucleoid; flagella E) chloroplasts; mitochondria
E) chloroplasts; mitochondria
An extensive system of internal membranes, called the ________________, is where carbohydrates and lipids are manufactured, and proteins are made that will be exported from the cell. A) nucleolus B) nucleoid C) mitochondria D) golgi apparatus E) endoplasmic reticulum
E) endoplasmic reticulum
The "9 + 2" architecture of microtubules is associated with which of the following structures? A) intermediate filaments B) centrioles C) centrosomes D) ribosomes E) flagella
E) flagella
Pores
Extensive nonpolar regions within a transmembrane protein can create a pore through the membrane Cylinder of beta sheets in the protein secondary structure called a b-barrel Interior is polar and allows water and small polar molecules to pass through the membrane
True or False: Prokaryotes have nuclei but no mitochondria or chloroplasts.
False
Cytoplasm
Fills the interior of the cell, it is a semifluid matrix.
Osmotic pressure
Force needed to stop osmotic flow Cell in a hypotonic solution gains water causing cell to swell - creates pressure If membrane strong enough, cell reaches counterbalance of osmotic pressure driving water in with hydrostatic pressure driving water out Cell wall of prokaryotes, fungi, plants, protists If membrane is not strong, may burst Animal cells must be in isotonic environments(pg.98)
Cell surface markers consists of___?
Glycoproteins, and glycolipid
The ER adds chains of sugar molecules to membrane proteins, and lipids converting them into ________?
Glycoproteins, and glycolipids
Cholesterol-Phospholipid interactions
Help stabilize the membrane: Make it more stable (less fluid) in higher temperatures and Less solid (more fluid) in lower temperatures.
Microtubules
Hold organelles in place and is responsible for things to move within the cell.
Phagocytosis
If the cell takes in in organisms or other fragments of organic material the process will be called _____?(pg.103)
Membrane fluidity
Influenced by the relative amounts of saturated and unsaturated fatty acid tails in membrane phospholipids.
Golgi Apparatus
Is an organelle who's function is packaging, and distribution of molecules throughout the cell.
Lysosomes
Is an organelle who's function is to break down old organelles and recycle their components. these organelles have a high levels of enzymes.
Tonoplast
Is the membrane around the vacuoles.
Theory of Endosymbiosis
It is believed that the modern day Eukaryote is driven by several different preexisting cells and the Mitochondria, chloroplast, and the nucleus were engulfed and made one cell.
Transporters
Membranes are very selective, allowing only certain solutes to enter or leave the cell, either through channels or carriers composed of proteins.
Cell surface receptors
Membranes are very sensitive to chemical messengers, which are detected by receptor proteins on their surfaces.
Cell surface identity markers
Membranes carry cell surface markers, that identify them to other cells. Cells can carry their own ID tags. They have specific combinations of cell surface proteins and protein complexes such as glycoproteins.
Endocytosis
Movement of substances into the cell Phagocytosis - cell takes in particulate matter Pinocytosis - cell takes in only fluid Receptor-mediated endocytosis - specific molecules are taken in after they bind to a receptor(pg. 102,101)
Exocytosis
Movement of substances out of cell Requires energy.(pg. 101,102)
Anchoring molecules are modified lipids with?
Nonpolar regions that insert into the internal portion of the lipid bilayer Chemical bonding domains that link directly to proteins
What are the four components of cellular membranes?
Phospholipid bilayer Transmembrane proteins Integral membrane proteins Cell surface markers (pg. 89&91)
Ribosomes
Organelles which carry out protein synthesis.
Explain Passive transport.
Passive transport is a movement of molecules through the membrane in which No energy is required Molecules move in response to a concentration gradient Diffusion is movement of molecules from high concentration to low concentration Will continue until the concentration is the same in all regions
The function of channels
Passively transport molecules across the membrane
What dies a bacteria's cell wall contain?
Peptidoglycan
Which organisms do NOT have centrioles? A) Animals and protists B) Plants and animals C) Fungi and protists D) Plants and fungi E) ALL living cells contain centrioles
Plants and fungi
Explain active transport
Requires energy - ATP is used directly or indirectly to fuel active transport Moves substances from low to high concentration (Against the [] gradient) Requires the use of highly selective carrier proteins(pg
Actin
Responsible for movement of the cell Crawling and contracting movement.
Which of these structures are found within bacterial cells? A) Chloroplasts B) Nucleus C) Mitochondria D) Golgi E) Ribosomes
Ribosomes
Prokaryotes
Simplest organism
Vesicles
Smaller sac that store and transport a variety of materials.
Solute
Solute A molecule dissolved in some solution; solutes dissolve only in solutions of similar polarity; for example, glucose (polar) dissolves in (forms hydrogen bonds with) water (also polar), but not in vegetable oil (nonpolar).
The composition of the interior protein network
Spectrins, and clathrins
Intermediate Filaments
Strongest piece of the cell stable and don't usually break down.
Phospholipid structure
Structure consists of Glycerol - a 3-carbon polyalcohol 2 fatty acids attached to the glycerol Nonpolar and hydrophobic ("water-fearing") Phosphate group attached to the glycerol Polar and hydrophilic ("water-loving") (pg.92)
Saturation
The act, process, or result of saturating a substance, or of combining it to its fullest extent.
Hyposmotic
The condition in which a ___________ solution has a lower osmotic concentration than that of a second solution.
Isosmotic
The condition in which the osmotic concentrations of two solutions are equal, so that no net water movement occurs between them by osmosis.
Cristae
The inner membrane of the mitochondria.
Matrix
The inner space that is surrounded by the Cristae
Coupled transport
The linked, simultaneous transport of two substances across a cell membrane, or another intracellular membrane.
Solvent
The medium in which one or more solutes is dissolved.
Passive transport
The movement of substances across a cell's membrane without the expenditure of energy.
Chloroplast
The organelle responsible for assembling its own food. Composed of: Inner membrane Outer Membrane Thylakoid disk Grana (stack of Thylakoid disks) Stroma
Intermembrane space
The space between the two membranes of the mitochondria.
Countertransport
The transport of one substance across a membrane, coupled with the simultaneous transport of another substance across the same membrane in the opposite direction.
Which of the following microscopes employing electron beams and has 1000 times the resolving power of a light microscope? A) Scanning electron microscope B) Transmission electron microscope C) Compound microscope D) Phase-contrast microscope E) Dark-field microscope
Transmission electron microscope
The function of receptors
Transport information into the cell
What are the membrane Proteins and their functions
Transporters (Carrier or channel proteins) Enzymes (chemical reactions on the cell membrane) Cell-surface receptors (chemical messengers detected) Cell-surface identity markers (ID tags; glycoproteins) Cell-to-cell adhesion proteins (temporary interaction btw cells Attachments to the cytoskeleton (surface proteins interacting)
Carrier proteins used in active transport include
Uniporters - move one molecule at a time Symporters - move two molecules in the same direction Antiporters - move two molecules in opposite directions
Osmotic concentration
When 2 solutions have different osmotic concentrations Hypertonic solution has a higher solute concentration Hypotonic solution has a lower solute concentration When two solutions have the same osmotic concentration, the solutions are isotonic Aquaporins facilitate osmosis(pg.98)
Mitochondria
a organelle which is known to power the cell. Composed of: Outer membrane Cristae (inner membrane) Matrix Intermembrane space
Eukaryotic cells are composed of three types of cytoskeletal filaments. How are these three filaments similar? a. They contribute to the shape of the cell. b. They are all made of the same type of protein. c. They are all the same size and shape. d. They are all equally dynamic and flexible
a. They contribute to the shape of the cell.
The difference between a gram-positive and gram-negative bacteria is— a. the thickness of the peptidoglycan cell wall b. the type of polysaccharide present in the cell wall c. the type and amount of protein in the cell wall d. the layers of cellulose in the cell wall
a. the thickness of the peptidoglycan cell wall
Lipid rafts
are heavily enriched in cholesterol and sphingolipids.
Flagella
are long, threadlike structure protruding from the surface of a cell that are used in locomotion, to execute transportation of that cell.
What do chloroplasts and mitochondria have in common? a. Both are present in animal cells. b. Both have an outer membrane and an elaborate inner membrane. c. Both are present in all eukaryotic cells. d. Both organelles function to produce glucose.
b. Both have an outer membrane and an elaborate inner membrane.
Which of these organelles is NOT associated with the production of proteins in a cell? a. Ribosomes b. Smooth endoplasmic reticulum (SER) c. Rough endoplasmic reticulum (RER) d. Golgi apparatus
b. Smooth endoplasmic reticulum (SER)
All eukaryotic cells possess each of the following except a. mitochondria b. cell wall c. cytoskeleton d. nucleus
b. cell wall
Eukaryotic cells are more complex that prokaryotic cells. Which of the following would you NOT find in a prokaryotic cell? a. Cell wall b. Plasma membrane c. Nucleus d. Ribosomes
c. Nucleus
3. What type of microscope would you use to examine the surface details of a cell? a. Compound light microscope b. Transmission electron microscope c. Scanning electron microscope d. Confocal microscope
c. Scanning electron microscope
Lysosomes function to a. carry proteins to the surface of the cell b. add short-chain carbohydrates to make glycoproteins c. break down organelles, proteins, and nucleic acids d. remove electrons and hydrogen atoms from hydrogen peroxide
c. break down organelles, proteins, and nucleic acids
2. The most important factor that limits the size of a cell is— a. the amount of proteins and organelles that can be made by a cell b. the rate of diffusion c. the surface-area-to-volume ratio of the cell d. the amount of DNA in the cell
c. the surface-area-to-volume ratio of the cell
Which of the following is not true of bacterial flagella? a. Bacterial flagella rotate producing a spiral wave. b. Bacterial flagella are anchored to a basal body. c. Bacterial flagella are powered by a proton gradient. d. Bacterial flagella are composed of microtubules.
d. Bacterial flagella are composed of microtubules.
Which of the following statements is NOT part of the cell theory? a. All organisms are composed of one or more cells. b. Cells come from other cells by division. c. Cells are the smallest living things. d. Eukaryotic cells have evolved from prokaryotic cells.
d. Eukaryotic cells have evolved from prokaryotic cells.
Proteins can move from the Golgi apparatus to a. the extracellular fluid b. transport vesicles c. lysosomes d. all of the above
d. all of the above
4. All cells have all of the following except— a. plasma membrane b. genetic material c. cytoplasm d. cell wall
d. cell wall
The function of spectrins
determines the shape of the cell
Peroxisome
function is to break down fatty acids, it does this by oxidizing the fatty acid. Essentially adding a hydrogen to it.
Pinocytosis
if the material the cell takes in is liquid, the process will be called______?(pg. 103)
extrusion
in which water is ejected through contractile vacuoles
Isosmotic regulation
involves keeping cells isotonic with their environment Marine organisms adjust internal concentration to match sea water Terrestrial animals circulate isotonic fluid
Nucleus
is a central organelle which is where genetic material is stored, denatured, and transcribed.
Endoplasmic Reticulum
is a organelle associated with transporting molecules throughout the cell and storing molecules. Smooth ER- Little to no ribosomes surround it. stores Ca2+ Rough ER- A lot of ribosomes surrounding it .
Cytoskeleton
is an internal protein scaffolding system. This hold the shape of the cell.
The lipid layer that forms the foundation of a cell's membranes is a bilayer formed of?
phospholipids
The simplest cells are found in the: A) eukaryotes B) prokaryotes C) multicellular animals D) fungi E) protists
prokaryotes
Function of the phospholipid bilayer
provides permeability barrier matrix for proteins