Physiology Final Exam - all content from 4 midterms

Exam 1

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Homeostasis is maintained by positive feedback.
True
False

False

Glycosidases are enzymes that breakdown carbohydrates.
True
False

True

An exergonic reaction releases energy.
True
False

True

Na+ can move across the phospholipid bilayer by passive diffusion.
True
False

False

Intracellular and extracellular fluids are in osmotic equilibrium.
True
False

True

Small lipophilic molecules can move across the phospholipid bilayer by passive diffusion.
True
False

True

The resting membrane potential of most cells is electroneutral (0 mV).
True
False

False

Secretory vesicles are formed from the Golgi apparatus.
True
False

True

ATP is required during primary active transport of an ion or molecule across a membrane.
True
False

True

Cytosol is considered an extracellular fluid.
True
False

False

The reaction [ A --> B + C + energy ] is an example of a catabolic reaction.
True
False

True

Na+ and Cl- are typically at higher concentrations in extracellular fluid compared to intracellular fluid.
True
False

True

A disaccharide is a type of nucleotide.
True
False

False

Glycolysis takes place within the mitochondria.
True
False

False

The tertiary structure of a protein describes how a single polypeptide chain folds into its three-dimensional shape.
True
False

True

Allosteric inhibitors decrease enzyme activity by directly competing with the substrate for its binding site on an enzyme.
True
False

False

Messenger RNA is produced within the nucleus.
True
False

True

Which organelle assembles amino acids into proteins?
Golgi apparatus
Ribosome
Smooth endoplasmic reticulum
Chromosome
Nucleus

Ribosome

Peptide bonds form which structural level of proteins?
Primary structure
Secondary structure
Tertiary structure
Quaternary structure

Primary structure

Pyruvate is a product of which process?
Electron transport system
Krebs cycle
Protein synthesis
Glycolysis

Glycolysis

Which type of tissue forms the lining of the digestive tract that faces the lumen?
Epithelial
Excitable
Endocrine
Connective

Epithelial

Which type of molecule might allow a protein to interact with a substrate?
Competitive inhibitor
Proenzyme
Allosteric inhibitor
Cofactor

Cofactor

Which of the following prevents passage of substances across an epithelium between adjacent cells?
Adhesion molecules
Tight junctions proteins
Microvilli
Gap junctions

Tight junctions proteins

Which best describes the enzyme lactase?
Nuclease
Lipase
Protease
Glycosidase

Glycosidase

Which group of elements make up most of the body mass?
Carbon, oxygen, and calcium
Carbon, hydrogen, and oxygen
Carbon, oxygen, and sodium
Carbon, hydrogen, and calcium
Carbon, sodium, and potassium

Carbon, hydrogen, and oxygen

Which ion or molecule is most likely to diffuse out of a cell down its concentration gradient by facilitated diffusion?
CO2
Na+
Cl-
K+
O2

K+

Which best describes the process of an endocrine cell being stimulated to release protein hormones it had stored in secretory vesicles?
Constitutive endocytosis
Regulated endocytosis
Regulated exocytosis
Constitutive exocytosis

Regulated exocytosis

Which is the compliment DNA base pair for cytosine?
Uracil
Thymine
Cytosine
Adenine
Guanine

Guanine

In aerobic respiration, approximately how many molecules of ATP are produced per molecule of glucose?
0
2
36
None of the above; anaerobic respiration consumes more ATP than it produces.

36

Which tissue type most commonly expresses cilia?
Nervous
Connective
Epithelial
Muscle

Epithelial

Which best describes hydrolysis?
Using water to breakdown a larger molecule
Storing water in its polymer form
Moving water across the plasma membrane
Using water to synthesize a larger molecule

Using water to breakdown a larger molecule

Which of the following molecules contains a phosphate group?
Glycerol
Amino acid
DNA
Fatty acid

DNA

Which best describes the response of a red blood cell placed in a hypertonic solution?
It will shrink.
It will not change size.
It will swell.
It will produce additional aquaporins to maintain osmotic equilibrium.

It will shrink.

Mucous is produced by which type of gland?
Exocrine gland
Endocrine gland
Neither are correct
Both are correct

Exocrine gland

Which of the following is not an example of an anabolic process?
Protein synthesis by ribosome
Glucose storage as glycogen
Production of ATP by the electron transport chain
ATP hydrolysis by an ATPase

ATP hydrolysis by an ATPase

According to Fick's Law of Diffusion, which of the following best describes how the properties of a given molecule relate to its rate of diffusion across a phospholipid bilayer?

1. Directly proportional to its water solubility; inversely proportional to its molecular weight
2. Directly proportional to its lipid solubility; inversely proportional to its molecular weight
3. Inversely proportional to its water solubility; directly proportional to its molecular weight
4. Inversely proportional to its lipid solubility; directly proportional to its molecular weight

2. Directly proportional to its lipid solubility; inversely proportional to its molecular weight

Which of the following is not a characteristic typically exhibited by connective tissue?
Maintains structure and supports linkage throughout the body
Cells are closely packed and form tight junctions with each other
Cells are scattered (i.e., not uniformly arranged) within tissue
Extracellular matrix is a defining structural and functional characteristic

Cells are closely packed and form tight junctions with each other

How does a competitive inhibitor affect a ligand-receptor interaction?
It binds a site other than the ligand binding site and blocks receptor activation

It binds a site other than the ligand binding site and activates the receptor

It binds the ligand binding site and blocks receptor activation

It binds the ligand binding site and activates the receptor

It binds the ligand binding site and blocks receptor activation

Which of the following best describes homeostasis?
Altering the external environment to maintain a constant internal state

Maintaining an internal environment in a permanently fixed state

Maintaining an internal environment in a state of dynamic constancy

Altering the external environment to maintain a fixed internal state

Maintaining an internal environment in a state of dynamic constancy

Which of the following is not an example of potential energy?
The resting membrane potential of a cell

The movement of ions through a membrane channel

The chemical bonds joining phosphate groups in ATP

The concentration gradient for Na+ across the plasma membrane

The movement of ions through a membrane channel

What is endocytosis?
The incorporation of material into a cell via a vesicle formed by the nuclear membrane

The release of material from a cell via a secretory vesicle fusing with the nuclear membrane

The incorporation of material into a cell via a vesicle formed by the plasma membrane

The release of material from a cell via a secretory vesicle fusing with the plasma membrane

The incorporation of material into a cell via a vesicle formed by the plasma membrane

A higher dissociation constant (Kd) value indicates which of the following?

A lesser tendency for the product to be formed from the reactants

A greater tendency for the product to be formed from the reactants

A faster forward reaction rate

A slower reverse reaction rate

A lesser tendency for the product to be formed from the reactants

In Fick's Law of Diffusion, the rate of diffusion of a molecule across the plasma membrane is inversely proportional to which of the following?

The magnitude of the concentration gradient of the diffusing molecule across the membrane

Surface area of the membrane

The permeability of the membrane to the diffusing molecule

None of the above

None of the above

How does the "Central Dogma" help organize our understanding of molecular biology?

It describes the process of DNA replication during cell division

It explains the flow and expression of sequence information from DNA to protein

It explains how the secondary and tertiary structure of proteins affect their function

It describes the physical structure and location of genes on a chromosome

It explains the flow and expression of sequence information from DNA to protein

Which of the following most accurately describes aerobic metabolism?

Glucose + Carbon Dioxide --> Oxygen + Water + ATP(C6H12O6 + 6 CO2 --> 6 O2 + 6 H2O + ATP)

Glucose + Oxygen + ADP + Pi --> Carbon Dioxide + Water + ATP(C6H12O6 + 6 O2 + 36 ADP + 36 Pi --> 6 CO2 + 6 H2O + 36 ATP)

Oxygen + Carbon Dioxide + ADP + Pi --> Glucose + Water + Energy(6 O2 + 6 CO2 + 36 ADP + 36 Pi --> C6H12O6 + 6 H2O + 36 ATP)

Glucose + Oxygen + ATP --> Carbon Dioxide + Water + ADP + Pi(C6H12O6 + 6 O2 + 36 ATP --> 6 CO2 + 6 H2O + 36 ADP + 36 Pi)

Glucose + Oxygen + ADP + Pi --> Carbon Dioxide + Water + ATP(C6H12O6 + 6 O2 + 36 ADP + 36 Pi --> 6 CO2 + 6 H2O + 36 ATP)

Close examination of a tissue sample reveals cells tightly packed together, forming a sheet-like row of cells within the organ. Some cells appear to express hair-like structures. On one side of the cells, there is open space lacking cells and on the other side there is less structured cellular tissue and some blood vessels. No significant extracellular matrix is observed between the cells. Which best describes this tissue?
Muscle tissue

Nervous tissue

Epithelial tissue

Connective tissue

Epithelial tissue

Which best describes the equilibrium constant (Keq) for a reaction?

The ratio of product concentrations to reactant concentrations at equilibrium
The concentration of products at equilibrium

The concentration of reactants at equilibrium

The rate of the reaction at equilibrium

The ratio of product concentrations to reactant concentrations at equilibrium
The concentration of products at equilibrium

Enzyme E catalyzes the conversion of Substrate A to Product B. The presence of Molecule Y dramatically reduces the rate of this reaction, and adding much higher concentrations of Substrate A can only minimally recover the reaction in the presence of Molecule Y. Which best describes the role of Molecule Y in this reaction?
Competitive activator

Allosteric inhibitor

Competitive inhibitor

Allosteric activator

Allosteric inhibitor

Which best describes how cells transfer energy from glucose to establish ion concentration gradients?

Glucose binds and energizes membrane ion transporters, generating ATP as a byproduct

Glucose binds and energizes membrane ion transporters, directly powering ion transport

Glucose catabolism generates ATP; ions move across the membrane following ATP gradients

Glucose catabolism generates ATP; ATP catabolism energizes membrane ion transporters

Glucose catabolism generates ATP; ATP catabolism energizes membrane ion transporters

Despite limited scientific evidence for performance benefits, during recovery from intense exercise, some professional athletes breathe in a face mask delivering air with a higher concentration of O2 than what is in normal air. Apply knowledge of Fick's Law and epithelial function to indicate whether each statement below is 'Correct' or 'Incorrect' in explaining the physiological concepts related to this intervention. Note: Each question is worth 1 point.

It increases the concentration gradient for O2 across the airway epithelium.

Correct

Incorrect

Correct

It increases the surface area available for gas exchange in the airway.
Correct
Incorrect

Incorrect

It increases the permeability of the airway epithelium to O2.
Correct

Incorrect

Incorrect

Its effectiveness is limited by the number of O2 transporter proteins expressed on the apical surface of airway epithelium.
Correct

Incorrect

Incorrect

Cystic fibrosis (CF) is a disease caused by decreased activity of an apical Cl- channel (CFTR), which transports Cl- out of the cell to the apical surface of the airways. Without intervention, CF can result the dehydrated of the airway surface, which can disrupt respiratory function. Apply knowledge of osmosis and epithelial function to indicate whether each proposed treatment would be 'Productive' or 'Unproductive' in maintaining a moist airway surface in the case of CF. Note: Each question is worth 1 point.

Administer an inhaled saline solution containing a high concentration of NaCl.
Productive
Unproductive

Productive

Administer a drug that blocks apical pathways of Na+ and Cl- absorption from the airway surface liquid into the cell.
Productive
Unproductive

Productive

Administer a drug that increases the activity of other Cl- channels in the apical membrane that can transport Cl- out of the cell.
Productive
Unproductive

Productive

Administer an inhaled solution containing a high concentration of the molecule mannitol, an osmotically active molecule that cannot cross epithelia.
Productive
Unproductive

Productive

A pharmaceutical company is developing a drug that needs to cross cell membranes to reach its target. They have two candidate drugs that are both small molecules (<1,000 g/mol) with identical core structures and functions. Drug A has a molecular weight of 400 g/mol and is lipophilic. Drug B has a molecular weight of 250 g/mol and is hydrophilic. Apply knowledge of Fick's Law and membrane dynamics to answer the following questions. Note: Each question is worth 1 point.

Which drug is capable of passively diffusing across the plasma membrane of cells.
Drug A
Drug B

Drug A

During clinical trials, different concentrations of drugs were tested. Which drug is more likely to show a saturation effect (plateau in effectiveness) at high blood concentrations?
Drug A
Drug B

Drug B

If the target of the drug was in the nucleus, which drug would more easily reach its target?
Drug A
Drug B

Drug A

If Drug B were to be modified by adding charged groups (such as -NH3+, or COO-), which drug would be more likely reach a target in the cytosol?
Drug A
Drug B

Drug A

For the image below, match each letter to its correct descriptor. Note: There are more descriptors than there are letters. Some descriptors will remain unmatched.

A-Directs cellular gene expression
B-Produces and modifies proteins
C-Packages and distributes proteins
D-Facilitates cell-environment interaction
E-Produces ATP

For the image below, match each letter to its correct descriptor. Note: There are more descriptors than there are letters. Some descriptors will remain unmatched.

A-Epithelial Tissue
B-Connective Tissue

Exam 2

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Peptide hormones easily diffuse across phospholipid bilayers.
True
False

False

Astrocytes are the glial cells primarily responsible for forming the blood brain barrier.
True
False

True

The parasympathetic nervous system controls 'fight or flight' responses.
True
False

False

Sarcomeres shorten in length during muscle contraction.
True
False

True

Neurotransmitters are typically released into blood capillaries.
True
False

False

Peptide hormones are typically released via exocytosis.
True
False

True

Action potentials can travel in either direction along the axon.
True
False

False

'White matter' refers to myelinated neural tissue.
True
False

True

Increased urine production is a result of sympathetic stimulation.
True
False

False

Acetylcholine is released by motor neurons at neuromuscular junctions.
True
False

True

A graded potential caused by Na+ influx is typically an excitatory signal (i.e., makes the neuron more likely to fire an action potential).
True
False

True

A monosynaptic reflex arc involves at least three neurons.
True
False

False

The peripheral nervous system includes the brain and the spinal cord.
True
False

False

Insulin promotes the reduction of blood glucose levels.
True
False

True

Intracellular cyclic AMP (cAMP) levels decrease when adenylyl cyclase is activated.
True
False

False

Control of blood glucose levels by alpha and beta cells of the pancreas is best described by which type of mechanism?
Neuroendocrine pathway

Simple endocrine reflex

Neuromuscular junction

Simple neural reflex

Simple endocrine reflex

Where are the receptors for peptide hormones located?
Cell membrane

Endoplasmic reticulum

Cytosol

Nucleus

Cell membrane

Where in the neuron is a graded potential measured and an action potential triggered?
Nucleus

Dendrites

Axon terminal

Axon hillock

Axon hillock

Which best represents the resting membrane potential of a neuron?
0 mV

-70 mV

-55 mV

+30 mV

-70 mV

Which best describes the relative plasma concentrations of insulin and glucagon during a state of fasting?
Insulin = low; Glucagon = low

Insulin = low; Glucagon = high

Insulin = high; Glucagon = high

Insulin = high; Glucagon = low

Insulin = low; Glucagon = high

Which of the following best describes the relative distribution of ions inside and outside of the cell?
Inside: high K+; Outside: high Na+ and Cl-

Inside: high Na+ and Cl-; Outside: high K+

Inside: high K+; Outside: high Na+; Equal Cl- in both

Inside: low K+; Outside: low Na+ and Cl-

Inside: high K+; Outside: high Na+ and Cl-

Where is Ca2+ stored in muscle cells?
Muscle fiber

Sarcoplasmic reticulum

Sarcoplasm

Sarcolemma

Sarcoplasmic reticulum

Which of the following muscle proteins directly binds and hydrolyzes ATP to generate force during muscle contraction?
Troponin

Myosin

Actin

Tropomyosin

Myosin

Which type of muscle controls body movement?
Smooth muscle

Cardiac muscle

Skeletal muscle

Skeletal muscle

What is the minimum number of neurons involved in a typical polysynaptic reflex arc?
1
2
3
4

3

Which type of cells are responsible for producing glucagon?
Alpha cells
Beta cells
Muscle cells
Exocrine cells

Alpha cells

Which is not a peptide hormone?
Glucagon
Insulin
Cortisol
Adrenocorticotropic hormone (ACTH)

Cortisol

Where is adrenocorticotropic hormone (ACTH) released from?
Posterior pituitary
Adrenal cortex
Hypothalamus
Anterior pituitary

Anterior pituitary

Where is a monosynaptic withdrawal reflex integrated?
Spinal cord
Hypothalamus
Peripheral nervous system
Cerebral cortex

Spinal cord

Which is a direct result of adenylyl cyclase activation?
Increase in intracellular glucose

Increase in intracellular adenosine triphosphate (ATP)

Increase in intracellular Ca2+

Increase in intracellular cAMP

Increase in intracellular cAMP

Which types of receptors could be targets of neurotransmitters at chemical synapses?
Only G protein-coupled receptors (GPCRs)

Either ligand-gated ion channels or GPCRs

Neither ligand-gated ion channels nor GPCRs

Only ligand-gated ion channels

Either ligand-gated ion channels or GPCRs

Which accurately describes a difference between the sympathetic and parasympathetic branches of the autonomic nervous system?

Sympathetic branch carries signals to tissues involved in 'fight or flight' responses but not to tissues involved in 'rest and digest' responses.

Sympathetic branch ganglia are located close to the spinal cord; Parasympathetic branch ganglia are located close to or within target tissues.

Sympathetic branch neurons project from the brain stem and pelvic regions of the spinal cord; Parasympathetic branch neurons project from the thoracic and lumbar regions of the spinal cord.

Sympathetic branch carries signals away from the central nervous system (CNS); Parasympathetic branch carries signals toward the CNS.

Sympathetic branch ganglia are located close to the spinal cord; Parasympathetic branch ganglia are located close to or within target tissues.

What would likely happen to the resting membrane potential if the cell membrane of a neuron suddenly became more permeable to Na+?

Membrane would depolarize

Membrane potential would not change

Membrane would repolarize

Membrane would hyperpolarize

Membrane would depolarize

The blood-brain barrier is least permeable to which of the following?
O2 and CO2
Small steroid hormones
Water-soluble ions
Lipid-soluble drug compounds

Water-soluble ions

Type 1 diabetes mellitus is best characterized by which of the following?
Excessive production of glucose by liver cells

Insufficient production of insulin by pancreatic beta cells

Reduced sensitivity of target tissues to insulin

Inability of cells to utilize glucose for energy

Insufficient production of insulin by pancreatic beta cells