BMS exam quiz questions

which ions are usually more concentrated outside the cell than inside?

sodium, chloride, calcium

which ion has the highest percentage moving across the membrane when a cell is at its membrane potential

potassium

how do potassium ions cross the cell membrane to move from the interior to the exterior of the cell

leak channels

which of the following statements about potassium’s concentration inside and outside of the typical cell is correct

150mmol/L inside, 5mmol/L outside

which of the following systems provide innate immunity

urinary

to which system is the prostate a part of

reproductive

which of the following systems is most responsible for restoring homeostasis to the body after some external or internal perturbation

endocrine

which system is responsible for collecting information from sensory neurons and processing the information to determine how to respond to a stimulli

central nervous system

which of the following organ’s functions include nutrient processing, and the production of blood clotting proteins, and immune factors

liver

if a patient weighed 80kg, what would be the approximate weight of their total body water (TBW)

48kg

if a 35 year old male had a body weight of 100kg, what would be the approximate volume of their plasma?

4.8L

which components are part of the body’s automatic control system that regulates homeostasis

receptors, effectors, coordination centers

when a baby is ready to be born, the pituitary gland secretes oxytocin. as the baby is being born it exerts pressure on the cervix, which stimulates the release of more oxytocin. this event is an example of what?

a positive feedback loop

normally right after eating a meal, there is an increase in an individuals triiodothyronine (T3) levels. the level of which of the following molecules would be expected to decrease in direct response to increasing T3 levels

thyroid stimulating hormone

what is the term given to a consecutive group of three mRNA nucleotides that is used to determine which amino acid should be put into place of a growing polypeptide chain

codon

what is the name of the proteins that guide the small subunit of the ribosome to the mRNA translation start site

elongation initiation factors

what is the role of tRNA during translation of the mRNA into protein

bring the correct amino acid to the ribosome

what is the difference between a coding and non-coding RNA

a non-coding RNA will never be translated into a protein

you are trying to develop a drug to inhibit the expression of a oncogene that is causing pancreatic cancer in men over the age of 50. which of the following natural molecules would it be useful to try to mimic in the design of your drug

microRNA

what is the purpose of the cell inhibiting the activity of elongation initiation factors (eIFs) during times of fasting

to save energy for necessary cell processes

an mRNA that translated which of the following class of proteins would have the shortest half-life

a protein involved in cell signaling events such as a kinase

how do microRNAs alter gene expression

they form a RNA induced silencing complex that binds to and degrades mRNA by destroying its poly(A) tail

what is recruited to the initiation site of mRNA translation last

large subunit of ribosome

what is the name of the three nucleotide sequence on a tRNA that recognizes the codon on the mRNA so that the correct amino acid is brought to the ribosome

anticodon

which two transport mechanisms require energy and moves molecules against their concentration gradients

secondary active transport, primary active transport

what is produce by primary active transport that is used by secondary active transport to move molecules across the cell membrane

an electrochemical gradient

which of the following statements is true about the sodium/potassium pump

it pumps three na+ out of the cell and two K+ into the cell

the Na+/glucose transporter is best described by which of the following

a secondary active symporter

a molecule binds to the surface of a cell and is engulfed by the plasma membrane into a vesicle that is brought into the cell. what type of transport is this

receptor-mediated endocytosis

which of the following transport mechanisms is used to dispose of waste products generated within cell

lysosome-mediated exocytosis

what type of transport is used to secrete specific hormones and other proteins out of the cells for use in other parts of the body

regulated exocytosis

a boy scout was given a cookie and he quickly ate it. he then proceeded to walk an elderly lady across the street. on the way back across the street, he escorted an elderly gentleman. what type of transport system most resembles the actions of the boy scout

primary active transport

what is the name of pumps that are used to establish and maintain a voltage across a plasma membrane

electrogenic pumps

what does the sodium/potassium pump use for energy

atp

which of the following molecules would most easily pass through a cell’s plasma membrane

small,non-polar, and soluble in lipids

what separates passive diffusion from facilitated and selective facilitated diffusion

passive diffusion does not require a protein channel or transport

which of the following transport methods require energy

secondary active transport

a molecule has moved across a plasma membrane via passive diffusion to a point at which its concentration is equal on both sides of the membrane. which of the following scenarios will happen now

the flux of molecules across the membrane will be equal in both directions

if you were a small ion and were in a hurry to get into a cell, which of the following methods would you prefer

facilitated diffusion through a channel

which of the following transporters bind to a molecule, changed its own shape, and release the molecule and the opposite side of the plasma membrane, all without the need for energy

carrier protein

based on fick’s law, which of the following scenarios will have a faster rate of flux

high concentration:low concentration ratio= 10, separated by 10 microns

if oxygen moves into the blood from the alveoli via passive diffusion, what does this suggest about the relative concentration of oxygen in these two areas

oxygen concentration is higher in the alveoli

how can you increase the rate of flux of a molecule from the outside of a cell to the inside of a cell if it moves through the membrane via facilitated diffusion

increase the concentration of the molecule outside the cell

for molecule Y to pass along its concentration gradient into the cell, molecule X must bind to a protein to allow Y to pass. what type of channel must molecule Y being using to pass into the cell

a gated channel protein

which of the following sites contains ribosomes that aid in the synthesis of proteins from mRNA

rough endoplasmic reticulum

which of the following drugs that is used to treat cancer functions by preventing dna from unwinding during replication

irinotecan

a molecule with which of the following characteristics is most likely able to pass right through the cells plasma membrane

a small,non-polar molecule

which of the following choices contain the four categories that are considered important parameters in a drug’s overall effectiveness

adsorption, distribution, metabolism, excretion

in which of the following compartments of the cell are ribosomes assembled

nucleolus

which of the following organelles can trigger apoptosis when cell conditions are so dangerous they could cause massive tissue destruction

mitochondria

how do tetracyclines kill bacteria

they prevent tRNA from binding to ribosomes so the bacteria can not make proteins

which of the following is the major role of the mitochondria

produce atp for the cell to use as energy

which of the following plays a major role in the separation of chromosomes during cell division

microtubules

which of the following class of proteins that are part of the cytoskeleton are primarily responsible for maintaining a cell’s shape and muscle contraction

microfilaments

What is the only type of RNA that is translated into protein?

mRNA

true or false: RNA nucleotides contain a ribose sugar while DNA nucleotides contain a deoxyribose sugar

true

Which of the following group of genes is most likely to be constitutively expressed?

Those involved in the maintenance of a cell's structure

which of the following is not a major step in DNA transcription

post-translational modification

what is the name of the region of DNA that controls whether a gene is to be transcribed and is the site at with RNA polymerase and transcription factors bind

promoter region

what does p53 do

it is a transcription factor that activates genes involved in dna repair and cell cycle arrest

What two things are put on the 5' and 3' ends of mRNA to protect it from being degraded within the cell?

A 7-methylguanosine molecule and a poly(A) tail

What is the name of the major enzyme that transcribes the DNA template into a mRNA strand?

RNA polymerase

Why is a single gene able to produce many different types of mature mRNAs?

Because different combinations of exons can be used to form the mature mRNA

true or false: both strands of dna are transcribed into mRNA

false

Which form of DNA is more easily accessed so that DNA can be replicated?

chromatin

Which of the following selections correctly describes how DNA nucleotides bind to each other to bring the two strands together to form a double helix?

A binds to T and C binds to G

What does it mean the DNA replication is semiconservative?

Each strand of new DNA consists of one parent strand and on daughter strand

The human genome contains about 6 billion nucleotides that need to be replicated during DNA replication. How is the cell able to complete this monumental task in about 8 hours?

Replication starts at many different points called origins of replication

What enzyme unwinds the DNA prior to replication?

DNA helicase

What is the name given to the short DNA fragments that are synthesized on the lagging strand?

okazaki fragments

What is added to the unwound DNA strands to keep them from re-binding to each other during the process of DNA replication?

single-stranded binding proteins

what enzyme adds nucleotides to the growing strands of replicating DNA

DNA polymerase

What is the name of the enzyme that couples the short DNA fragments that are synthesized on the lagging strand together?

DNA ligase

What type of bonds are primarily responsible for keeping the two strands of DNA in its double helix formation?

hydrogen bonds

Which of the following IS NOT a type of membrane receptor?

nuclear hormone receptor

Which of the following types of receptors is best described by the following statement?

When a molecule binds to this type of receptor, the shape of the receptor is changed to allow an

ion to pass from the extracellular matrix to the cytoplasm"

ion channel receptor

The binding of acetylcholine to a surface receptor allows sodium ions to enter the cell. What type of receptor does acetylcholine bind to in this instance?

ion channel receptor

Which of the following receptors is associated with fast, varied responses such as those transmitted by neurotransmitters?

g-protein coupled receptors

Which is the correct order for the three main stages of cell signaling that occur when a ligand binds to a receptor?

reception,transduction, response

Which of the following structural units is found in G-protein coupled receptors?

They contain seven alpha helices that span the plasma membrane

true or false: the insulin receptor is a tyrosine kinase receptor that autophosphorylates when bound to insulin

true

Tumor necrosis factor alpha (TNF-a) is a well known trigger of inflammation. TNF-a binds to the TNF receptor. By what mechanism does the interaction between TNF-a and its receptor stimulate inflammation?

Binding of TNF-o to the TN receptor activates NF-KB, which affects the expression of genes involved in the inflammatory process

Which of the following molecules binds to adrenergic G-protein coupled receptors on cells to promote the breakdown of glycogen so that the cell has access to glucose so it can produce energy quickly?

epinephrine

true of false: estrogen only exerts it affects on cells by binding to a membrane receptor

false

What is the main neurotransmitter the somatic nervous system release at the neuromuscular junction?

acetylcholine

What neurotransmitter do almost all post-ganglionic sympathetic neurons release?

noradrenaline

What is the main difference between the autonomic and somatic nervous system?

The autonomic system controls involuntary functions while the somatic system controls voluntary movement

Which of the following organs are controlled by the sacral region of the autonomic nervous system? select all that apply

bladder, genitals

If you are in the marsh and see a python, which of your nervous systems is most likely going to be immediately activated?

sympaethetic

Which of the following system contains a single long efferent neuron to ensure the signal is quickly received by its intended target?

somatic

true or false: In the sympathetic nervous system the pre-ganglionic neurons are generally short compared to the post-ganglionic neurons.

true

efferent neuron

carries signal away from the central nervous system that causes a response within a target organ or muscle

sensory neuron

receives and transmits a peripheral stimulus to the central nervous system

What neurotransmitter(s) is primarily released by the pre-and post-ganglionic parasympathetic neurons?

acetylcholine

What is unique to the heart (which is made up of cardiac muscle) that is not found in skeletal or smooth muscle?

 

The heart generates its own electrical stimuli

Which of the following contains a group of myocytes that initial the action potential in the heart that cause it to beat?

sinoatrial node

What do cardiac muscles have that allow the electrical potential to be propagated quickly between neighboring cells. 

gap junctions

What is the term given to the process when a membrane voltage increases to become less negative?

depolarization

When pacemaker cells of the heart reach the threshold voltage of -40 mV, which of the following events is the first to occur?

Ca2+ channels open and this ion flows into the cells

At it reaches a threshold of -70 mV, which of these events happens within a myocyte.

Na⁺ channels open and Na⁺ rapidly enters the cell