Bio module 3 SG
What is generally the maximum magnifying capacity of a light microscope
2000
What is typically the result of receptor up regulation
A hormones signal is amplified
Why is it advantageous for cells to be small
A small cell has a small volume relative to surface area which allows efficient transport through the plasma membrane
What does ABC transporter use to move larger ions and molecules across the cell membrane
ATP
Which neurotransmitter opens ligand-gated sodium channels
Acetylcholine
while testing an experimental drip on a vertebrate you notice that the cell vortex becomes more fluid and the cell loses its ability to move. Despite this you determine that cell strength is maintained. Based on these observations you correctly conclude that the drug most directly affects
Actin filaments
DNA is associated with certain proteins, forming a complex called:
Chromatin
Once ligand molecules binds to receptors in coated pits of a plasma membrane the next step of receptor-mediated endocytosis would be
Coated vesicle forms by endocytosis
The following are different types of neurotransmitters except
Cyclic adenosine
When food is scarce the amoeba-like cellular slime mold dictyostelium secretes which compound
Cyclic adenosine monophosphate
Name the part of the cell outside the nucleus
Cytoplasm
During enzyme-linked reception, signal molecules bind to two tyrosine kinase receptors. The receptor proteins move closer together in the plasma membrane and pair, forming a(n) ____.
Dimer
Scaffold proteins ensure that signals are relayed
Efficiently
Phosphate comes from ATP
Enzyme linked receptor
Protein kinase sites are active
Enzyme linked receptor
Which cellular mechanism ejects products such as hormones by the fusion of a vesicle with the plasma membrane
Exocytosis
Enzymes called protease sin the ER lumen catalyze folding of proteins into proper conformations
False
In cell membranes cholesterol and glycoproteins are exposed to the extra cellular surfaces for cell recognition and adhesion to other cells
False
In scanning electron microscopy, an electron beam passes through a very thin slice of specimen and then falls onto a photographic plate or a fluorescent screen
False
Kinesin transports organelles toward the minus end of a microtubule
False
Mitochondria play an important role in cell necrosis
False
Plasmolysis occurs in plant cells when the soil or water contains low concentration of salts or fertilizers
False
When an enzyme linked receptor is activated a conformational change activated the extra cellular kinases
False
A basal body anchors what part of a cell
Flagellum
In the sodium-potassium pump, sodium ion release causes the carrier protein to return to its original shape and releases two K+ ions into the cell
Flase
Which of the following is necessary for a cell to maintain its function and growth
Food
The hydrolysis of GTP to GDP deactivates the
G protein
DAG is the second messenger
G protein linked receptor
GDP is replaced with GTP
G protein linked receptor
What protects a cell and may help keep other cells at a distance
Glycocalyx
Which strategy is the most effective for larger cells to have an effective surface area to volume ratio
Having thin finger like projections
Fluid that has a higher osmotic pressure than a cell is called
Hypertonic
If the concentration of solutes in a cell is less than the concentration of solutes in the surrounding fluid then the extra cellular fluid is said to be
Hypertonic
In the phospholipase C signal transduction pathway which pair of second messengers is produced
IP3 and DAG
Which of the following pairs is correctly matched
Integrins-receptors
Sodium ions enter the cell
Ion channel linked receptor
A transmembrane protein differs from other membrane proteins because
It completely extends through the membrane
A patient who has had a severe hemorrhage accidentally receives a large transfusion of distilled water directly into a major blood vessel. What effect will this have on the patient
It will have serious perhaps fatal consequences because the red blood cells could swell and burst
The ratio of the size of the image seen with the microscope to the actual size of the object is called
Magnification
Sodium-potassium pumps help to maintain a desperation of charges across the plasma membrane which is called the
Membrane potential
Which one of these are the most convenient unit for measuring cells
Micrometer
You isolate a cellular structure and determine that it is composed of a-tubulin and b-tubulin. Based on this evidence, you correctly identify this structure as a
Microtubule
Which of the following organelles plays an important role in apoptosis or programmed cell death
Mitochondria
Which two organelles are responsible for converting energy into forms that can be used by cells
Mitochondria and chloroplasts
Which of the following serves as a framework for the orderly distribution of chromosomes during cell divisions
Mitotic spindle
What can happen when GABA binds to its receptor
Neural signaling is inhibited
What transmits information electrically and chemically
Neurons
A single cell in a smokers lung has become cancerous it doubles its DNA and divides much faster than a normal lung cell. The most likely change that would have caused this condition took place in the..
Nucleus
Which statement about G protein is false
One subunit binds ATP
Specialized structures within a living cell are known as
Organelles
What method does a human white blood cell employ to employ to engulf a bacterial cell
Phagocytosis
Which statement about plasma membranes is false
Plasma membranes prevent communication with other cells
Which molecule is least likely to cross a cellular membrane by simple diffusion
Potassium ion
Choanoflagellates are important in the study of cell communication evolution because choanoflagellates have
Protein kinases similar to those in animals
If the cells are physically close to one another a signaling molecule on one cell may combine with a ..... on another cell
Receptor
Which is a part of a signal transduction pathway that enables vision in dim light in vertebrates
Rhodopsin
What does the nucleolus within the nucleus synthesize
Ribosomal RNA
What is the process in which one activated receptor can give rise to a thousands of final products
Signal amplification
The outer part of a G protein linked receptor binds to a ........ and it's inner part binds to a ......
Signaling molecule; G protein
You light a scented candle in the guest bathroom. Within a few minutes you can smell the candles scent throughout the hallway. What process is occurring?
Simple diffusion
What type of molecule can rapidly cross a plasma membrane
Small, hydrophobic molecules
How does the scanning electron microscope differ from the transmission electron microscope
The SEM yields a 3D image of the object being studied
Evidence that all living cells have a common origin is best illustrated by
The basic similarities in cell structure and chemistry
In cells that are constantly involved in secretion an equivalent amount of membrane must be returned to the interior of the cell for each vesicle that fuses with the plasma membrane if this does not occur then what would happen
The cell surface will keep expanding
In cells that are constantly involved in secretion an equivalent amount of membrane must be returned to the interior of the cell for each vesicle that fuses with the plasma membrane; if this does not occur then what would happen
The cell surface will keep expanding
Which statement about centrioles is false
The have a 9+2 arrangement of microtubules
The term fluid mosaic model refers to
The movement of lipids and integral proteins within the lipid bilayer
Under which of the following situations would receptor downregulation most likely occur
The number of receptors in the plasma membrane is too low
In the cAMP signal transduction pathway a protein kinase is activated. What happens next
The protein kinase activates a cellular response.
Scaffold proteins organize groups of intracellular signaling kinases into signaling complexes
True
The gas ethylene is a plant hormone that regulates a variety of processes including seed germination and ripening of fruit
True
The many short appendages that a cell has are called cilia
True
What process halts the net movement of water from a hypotonic solution into a plants cells and often provides the structural support to many plants?
Turf or pressure
Peripheral proteins are linked to either surface of the plasma membrane by
bonding to integral proteins through noncovalent interactions.
Phosphodiesterase catalyzes the conversion of
cAMP to AMP
When the net movement of water in and out a cell is zero that solution is said to be
isotonic
Which of the following is a key component of the cytoskeleton
microtubules
Cells that secrete large amounts of glycoproteins have many golgi stacks
True
How are hormones produced by endocrine glands typically transported to target cells
By the blood
The smooth ER is the primary site for the synthesis of phospholipids and cholesterol needed to make
Cell membranes
What happens during the Curran's port of glucose and sodium ions
The transport of glucose powers the transport of sodium; glucose molecules are transported against their concentration gradient
What happens when Ras proteins become stuck in their "on" state
There is unregulated cell division
Which statement about receptors is false
They are also called ligands
How are integral proteins unique in cell membranes
They are firmly bound to the membrane
Which statement about Ras proteins is false
They are inactivated when phosphorylated
Which of the following statements about phospholipids is flase
They contain three fatty acid chains
Which of the following is not a property of membranes
They inhibit the passage of materials
The role of ATP in the sodium-potassium pump is
To assist a Na+ to bind to a carbohydrate
Most intracellular receptors are what type of protein
Transcription factors
Carrier proteins are also called
Transporters
Almost every vertebrate cell has a primary cilium, a single cilium on the cell surface that serves as a cellular antenna
True