test 2

which scenario best describes a double blind study

neither the investigator nor the subjects know if they are in the experimental or control group

which statement about g proteins is false

one subunit binds ATP

what type of molecule can rapidly cross a plasma membrane

small hydrophobic molecules

GDP replaced with GTP

G PROTEIN LINKED RECEPTOR

the hydrolysis of GTP to GD deactivates the ______

G protein

DAG is the second messenger

G protein linked receptor

which is an example of a second messenger

GABA

how do gap junctions DIFFER from desmosomes

GAP junction provides communication between cells

the main signaling cascade for cell division and differentiation is in the _______kinase.

MAP kinase

what have studies of glucose transport in liposomes revealed?

binding of glucose triggers a conformational change in the carrier protein

which process is a function of peroxisomes

detoxification

anchor cell to the extracellular matrix

integrin

proteins that are destined to become associated with the inner surface of the plasma membrane are__________

made on the free ribosomes in the cytoplasm

which of the following organelles plays an important role in apoptosis (programmed cell death)

mitochondria

during an infection white blood cels travel to the site and phagocytize the pathogens......purpose of this is to_______

mix the pathogens

how does prokaryotic cell differ from eukaryotic cell

prokaryotic cell has NON membrane -enclosed organelles

unicellular eukaryotes

protists

what is the process where one activated receptor can give rise to thousands of final products

signal amplification

transmit information into cell

signal transduction receptors

which stimuli most directly causes the venus fly trap to catch an insect

touch

how many times do g protein linked receptors loop back and forth through the plasma membrane

7

the cis face of the golgi complex is most directly involved in which process

accepting vesicles from the ER

chimpanzee

animal

prokaryote

bacteria

allow selective transport of ions or molecules

channels

the sodium potassium pump is a carrier protein that maintains a __________gradient across the plasma membrane.

concentration

what type of microscopy uses a laser to excite fluorophones in just a thin slice through a cell

confocal microscopy

what is an example of a sessile organism

coral

catalyze reactions which take place within or along membrane surface

membrane bound enzymes

the term "fluid mosaic model" refers to the ______

movement of lipids and integral proteins within the lipid bilyaer

what is the ultimate source of genetic variation within a population

mutations in DNA

one of the conclusions from darwin's theory is__________________.

organisms living today DESCENDED FROM modifications from previously existing forms

________ are loosely associated with the phospholipid bilayer, whereas _______are tightly bound to it.

peripheral proteins integral proteins

what method does human white blood cell employ ti engulf a bacterial cell

phagocytosis

during SIGNAL TRANSDUCTION involving G protein and cAMP--what do protein kinases ADD to target proteins?

phosphate groups

in an experimental evaluation of a new drug, what is the purpose of a placebo

placebo removes potential PSYCHOLOGICAL BIAS of the patient in the study

oak tree

plant

which organizational unit includes the fewest species of organisms

population

which molecule is least likely to cross a cellular membrane by simple diffusion

potassium ion

use ATP to transport solutes

protein pumps

PURPOSE of cilia and flagella in cells?

provide movement for the cell

which statement about receptors is dalse

they are called ligands

how are integral proteins unique in cell membranes

they are firmly bound to the membrane and can only be released with a detergent

which statement about centrioles is FALSE

they have a 9 x 2 arrangement of microtubules

which statement about lipid bilayers is FALSE

they're inflexible

role of ATP in the sodium-potassium pump is to_________

transfer salt OUTSIDE of the cell

primary function of mitochondria

transformation of energy

what happens during the cotransport of glucose and sodium ions ?

BOTH are transported AGAINST their concentration gradient

as a result of testing an experiment drip on a vertebrae cell. you notice that the cell cortex becomes more fluid and although the cell remains strong it loses ability to move based on the evidence , you correctly conclude that the drug most directly affected the ___________

actin filaments

what type of cellular junction cements cells together that use adhering as a belt around each cell

adhering junctions

the smooth ER is the primary site for synthesis of phospholipids and cholesterol needed to make _________

cell membranes

during enzyme-linked reception, signal molecules bind to tyrosine kinase receptors. these receptor proteins move close together in the plasma membrane and PAIR forming a _______________

dimer

suppose a particular protein is produced in excess of the cell's needs. what kind of mechanism will intervene to stop production

homeostatic

if the concentration of the solutes in a cell is LESS than the concentration in the surrounding fluid...then the extracellular fluid is said to be ________

hypertonic

when tissues organize, WHAT do they form

organ

what is the passive movement of water along the concentration gradient

osmosis

which is a by product of photosynthesis

oxygen

in the figure, what is the role of structures between the membranes

they allow transport of small molecules and ion between adjacent cells

what is an end product of cellular respiration

CO2

WHAT IS a distinct characteristic of asexual reproduction

a cell splitting into identical halves

to which phylum do humans belong

chordate

scaffolding proteins ensure signals are relayed ______________.

efficiently

sodium ions enter the cell

ion channel linked receptor

phosphate comes from ATP

enzyme linked receptor

why can cholesterol act as a fluidity buffer in cell membranes

it is slightly amphipathic because of the presence of a hydroxyl group

a receptor on the cell surface usually has several domains. what is the function of the external domain i

its the DOCKING SITE for a signaling molecule

intermediate filaments are most closely associated with which of the following

keratins

during phagocytosis, what may fuse with the vacuole to further degrade the ingested material?

lysosome

based on knowledge of basic geometric shapes, what is the actual surface area to volume ratio for figure B in the accompanying figure

.06

which best describes a result of sexual reproduction

2 sex cells combine to form a fertilized cell

adenylyl cyclase catalyses the reaction in which_____

ATP converted into cAMP

which organelle can be considered a SORTING, PROCESSING, AND PACKAGING CENTER

GOLGI complex

typically the gate of an ion channel remains closed until a ______binds to the receptor

LIGAND

a DNA molecule is made of_________

NUCLEOTIDES

what activates protein leinase C

PIP 2

what large molecules are essential in determining the structure and function of tissues and cells

PROTEINS

which process halts the net movement of water from a hypertonic solution into a plants cells and often provides the structural support to many plants

TURGOR PRESSURE

would would be the ULTIMATE EFFECT of an ecosystem if decomposers were eliminated?

all life would cease as nutrients would no longer be available

since sodium potassium pumps transport sodium OUT and potassium IN , what type of carrier proteins are they?

antiporters

what represents the most basic level of chemical organization

atom

evidence that all living cells have a common origin id best illustrated by the

basic similarities in all structure and chemistry

peripheral proteins are linked to either the surface area of the plasma membrane by

binding to integral proteins through non covalent interactions

which explanation best describes the asymmetrically oriented structure of proteins in the cell membrane

each type of protein has its own function

protein kinase sites are active

enzyme linked receptor

you want to determine the location of a PROTEIN in a cell using a colored stain, which is the best technique

fluoresence microscopy

bread mold

fungi

plasmodesmata of plants cells are functionally equivalent to the ________of animal cells

gap junctions

many extracellular receptors are transcription factors -when activated, they activate or repress specific _______

genes

information in living organisms is translated by which mechanism

genes hormones and neurotransmitters

the benefit of sexual reproduction over asexual?

interaction of the genes from both parents brings about genetic variation

the LARGEST and MOST COMPLEX assembly of proteins in most eukaryotic cells are the ___________

nuclear pores

a single cell in a smokers lung has become cancerous. it doubles its DNA and divides FASTER than a normal lung cell. the cause of condition took place in the _______of the cell

nucleus

chanoglagellates have been important for the study of cell communication evolution because they have____________.

protein kinases similar to those in animals

cellular structure indicated by the arrow in the accompanying figure is responsible for

protein synthesis

if a toxin, such as bacterial toxin, destroys ribosomes what cellular activity will be affected first

protein synthesis

what is required for facilitated diffusion to take place?

transmembrane protein

which statement best describes the activity of the sodium-potassium pump

transports 3 sodium ions OUT ' in exchange for 2 potassium ions IN

which is a major group of enzyme-linked receptors

tyrosine kinases

upon observing a cell of grass blade, you notice a prominent sac that occupies a large portion of the cell. which organelle is this

vacuole