final mock exam - principles of biomedical sciences (pbs) - parker university

Which phase directly follows ventricular systole?

Isovolumetric relaxation

Isovolumetric contraction

Ventricular filling

Atrial systole

Isovolumetric relaxation

According to the Frank-Starling mechanism, increased preload leads to:

Decreased venous return

Decreased afterload

Increased stroke volume

Decreased stroke volume

Increased stroke volume

What phase of the cardiac cycle follows the closure of the AV valves and the generation of the first heart sound (S1)?

Atrial contraction

Isovolumetric contraction

Passive ventricular filling

Isovolumetric relaxation

Isovolumetric contraction

What best describes the blood flow during the meso-diastole phase of the cardiac cycle?

Active ventricular filling from atrial contraction

Aortic valve opens; blood moves into the Aorta

Isometric relaxation with no volume change

Passive filling from atria to ventricles

Passive filling from atria to ventricles

Which circuit has lower vascular resistance?

Both have the same resistance

Depends on the body activity

Systemic

Pulmonary

Pulmonary

Which valves are closed during the ejection phase of the cardiac cycle? (MACA, Select all that may apply)

Pulmonary valve

Tricuspid valve

Aortic valve

Bicuspid (mitral) valve

Tricuspid valve, Bicuspid (mitral) valve

Which of the following is characteristic of active transport? (MACA, Select all that may apply)

Moves down its concentration gradient

Does not need an energy source

Needs an energy source

Moves up its concentration gradient

Needs an energy source, Moves up its concentration gradient

Which of the following are considered insoluble molecules that vary with cell type?

Centrioles

Ribosomes

Organelles

Inclusions

Inclusions

Water channels are called __________.

Chemical-gated channels

Electrical gated channels

Aquaporins

Leak channels

Aquaporins

The intracellular fluid packed with the organelles of a cell is called _______.

Cytoplasm

Nucleus

Plasma

Phospholipid

Cytoplasm

The plasma membrane not only provides a protective boundary but also determines which substances enter or exit the cell. This is called:

Selective Permeability

Diffusion

Membrane Potential

Osmosis

Selective Permeability

In a cell, proteins are synthesized at the_________.

Golgi apparatus

Mitochondria

Smooth endoplasmic reticulum

Ribosomes

Ribosomes

The plasma membrane is composed mostly of:

Phospholipids and proteins

Carbohydrates and steroids

Phospholipids and steroids

Proteins and steroids

Phospholipids and proteins

How is total force calculated from 3D components?

Add all components

Substract Fy from Fz

Use square root of the sum of squares

Multiply components

Use square root of the sum of squares

Which of the following best describes an isometric muscle contraction?

The muscle shortens while producing force

The muscle lengthens while producing force

The muscle produces force without changing length

The muscle relaxes completely under load

The muscle produces force without changing length

What describes a scalar quantity?

Magnitude only

Direction only

Magnitude and direction

Neither magnitude nor direction

Magnitude only

Which of the following increases water solubility?

Methyl group

Long carbon chain

Double bounds

Hydroxyl group

Hydroxyl group

During photosynthesis, plants convert carbon dioxide and water into glucose and oxygen. What is the balanced equation for this process?

6 CO₂ + 6 H₂O → C₆H₁₂O₆ + 6 O₂

6CO₂ + 12H₂O → C₆H₁₂O₆ + 12O₂

CO₂ + H₂O → CH₂O + O₂

6CO₂ + 6H₂O → 2C₆H₁₂O₆ + 6O₂

6 CO₂ + 6 H₂O → C₆H₁₂O₆ + 6 O₂

Proteins are composed of:

Amino Acids

Nucleotides

Fatty Acids

Sugars

Amino Acids

What property of carbon makes it essential in forming large organic molecules?

Its ability to form four covalent bonds

Its high electronegativity

Its ability to dissolve in water

Its large atomic size

Its ability to form four covalent bonds

The aqueous solution with the lowest pH is:

0.01 M HCl.

0.1 M HCl.

0.1 M formic acid (pKa = 3.75).

10–12 M NaOH.

0.1 M acetic acid (pKa = 4.86).

0.1 M HCl.

lowest pH = strongest acid at highest concentration

Which compound is a diprotic acid?

CH3COOH

NH4+

H2CO3

H3PO4

CH3CH2OH

H2CO3

What is the significance of enantiomers in thalidomide?

Both enantiomers are equally therapeutic

Enantiomers are irrelevant to its function

Thalidomide has no enantiomers

One enantiomer treats nausea, while the other causes birth defects

One enantiomer treats nausea, while the other causes birth defects

Which acid-base disorder results from low blood pH?

Alkalemia

Alkalosis

Acidosis

Hyperoxia

Acidosis

The sulfhydryl group is important in:

Protein folding

DNA replication

Sugar digestion

RNA synthesis

Protein folding

The reaction A + B → C has a ΔG'° of -20 kJ/mol at 25°C. Starting under standard conditions, one can predict that:

At equilibrium, the concentration of C will be less than the concentration of A.

When A and B are mixed, the reaction will proceed rapidly toward the formation of C.

At equilibrium, the concentration of C will be much greater than the concentration of A or B.

At equilibrium, the concentration of B will exceed the concentration of A.

C will rapidly break down to A + B.

At equilibrium, the concentration of C will be much greater than the concentration of A or B.

Lipids are primarily composed of:

Carbon, hydrogen, and oxygen

Carbon, oxygen, and nitrogen

Carbon, phosphorus, and sulfur

Carbon, hydrogen, and nitrogen

Carbon, hydrogen, and oxygen

The primary site of amino acid catabolism is:

Kidneys

Brain

Muscle

Liver

Liver

Coenzymes typically function by:

Serving as antioxidants only

Transferring functional groups or acting as cosubstrates

Providing structural support

Permanently binding to enzymes

Transferring functional groups or acting as cosubstrates

In metabolic pathways, why are some reactions essentially irreversible?

Their ΔG is highly positive

They occur in the nucleus

They involve gases

Their ΔG is highly negative, driving the pathway forward

Their ΔG is highly negative, driving the pathway forward

Lipids are hydrophobic because they are:

Polar

Acidic

Ionic

Nonpolar

Nonpolar

Which vitamin-derived compound acts as a coenzyme in redox reactions?

Vitamin D

NADH/NAD+

Vitamin A

Vitamin C

NADH/NAD+

Acetyl-CoA is a central metabolite in the catabolism of:

Only proteins

Carbohydrates, fats, and amino acids

Only carbohydrates

Only fats

Carbohydrates, fats, and amino acids

Proteins are made up of:

Amino acids

Fatty acids

Polysaccharides

Nucleotides

Amino acids

What does the First Law of Thermodynamics state?

Systems tend toward equilibrium

Energy can be created but not destroyed

Energy cannot be created or destroyed

Energy is always lost as heat

Energy cannot be created or destroyed

Amino acids are classified based on the properties of their:

R group (side chain)

Hydrogen atom

Amino group

Carboxyl group

R group (side chain)

Coupling reactions in metabolism allows:

Energy to be stored indefinitely

Spontaneous processes to stop

Endergonic reactions to proceed using exergonic reactions

Cells to conserve energy

Endergonic reactions to proceed using exergonic reactions

A small decrease in the radius of a blood vessel leads to:

A linear decrease in flow

No significant change in flow

A dramatic decrease in flow due to the radius being raised to the fourth power

An increase in pressure but not in resistance

A dramatic decrease in flow due to the radius being raised to the fourth power

Which force opposes gravity in a submerged object?

Surface tension

Friction

Buoyant force

Elastic recoil

Buoyant force

What is the most likely outcome of measuring a patient's blood pressure using an oversized cuff?

The blood pressure reading will be falsely elevated

The blood pressure reading will be falsely lowered

The blood pressure reading will be unaffected

The cuff will not inflate properly

The blood pressure reading will be falsely lowered

Which of the following is a function of proteins in the body?

Storing genetic information

Insulation

Energy storage

Catalyzing biochemical reactions

Catalyzing biochemical reactions

Entropy in biological systems must be managed because:

Disorder favors growth

Living systems are highly ordered and require energy to maintain this order

It always decreases with ATP use

Energy conservation requires less entropy

Living systems are highly ordered and require energy to maintain this order

Excess nitrogen from amino acid metabolism is excreted as:

Nitric oxide

Ammonia

Uric acid

Urea

Urea

Fructose-1-phosphate can be hydrolyzed into fructose and inorganic phosphate (Pi) with a ΔG° of -16.0 kJ/mol. If ATP can be hydrolyzed into ADP and Pi with a ΔG° of -30.5 kJ/mol, what is the free-energy change for the reaction shown?

fructose + ATP → fructose-1-phosphate + ADP

14.5 kJ/mol

-46.5 kJ/mol

-14.5 kJ/mol

46.5 kJ/mol

–14.5 kJ/mol

(ΔG = –16 – (–30.5) = –16 + 30.5 = +14.5? → BUT reaction is reversed for phosphorylation → correct answer: –14.5 kJ/mol)

The urea cycle primarily occurs in which organ?

Pancreas

Liver

Kidney

Intestines

Liver

Deficiency of iodine can lead to:

Anemia

Osteoporosis

Hypothyroidism and goiter

Rickets

Hypothyroidism and goiter

Endergonic reactions:

Always occur spontaneously

Release heat

Are irreversible

Require input of energy

Require input of energy

Which of these lipids is an example of a steroid?

Oleic acid

Phospholipid

Cholesterol

Triglyceride

Cholesterol

What is the primary monosaccharide transported in the bloodstream?

Fructose

Galactose

Ribose

Glucose

Glucose

Calcium is important for:

Enzyme activation

Blood clotting and bone health

Hormone synthesis

Energy production

Blood clotting and bone health

Transamination involves the transfer of:

A phosphate group to glucose

An amino group from an amino acid

Glucose into glycogen

Fatty acids to acetyl-CoA

An amino group from an amino acid

Glycogen is primarily stored in:

Bones and cartilage

Blood plasma

Kidney tubules

Liver and muscles

Liver and muscles

____________ refers to a state of relaxation, while _____________ refers to a state of contraction.

Diastole, Systole

Systole, Diastole

Diastole, Systole

Which condition would most likely result in a diastolic murmur?

Mitral stenosis

Aortic stenosis

Atrial septal defect

Tricuspid regurgitation

Mitral stenosis

Which of the following is the most influential in changing blood flow?

Vessel radius

Blood pressure

Blood viscosity

Vessel length

Vessel radius

Where is the mitral valve located?

Between left atrium and left ventricle

At the opening of the pulmonary artery

Between right atrium and right ventricle

Between left ventricle and Aorta

Between left atrium and left ventricle

Which of the following is the muscle layer of the heart?

Epicardium

Endocardium

Myocardium

Pericardium

Myocardium

Which has the lowest velocity of blood flow?

Arterioles

Veins

Aorta

Capillaries

Capillaries

Which vessels serve as major blood reservoirs in the body?

Veins

Capillaries

Arteries

Arterioles

Veins

Hydrostatic pressure depends on:

Flow velocity

Tube radius

Fluid column height

Fluid temperature

Fluid column height

According to Poiseuille's Law, blood flow is most affected by:

Blood pressure

Blood volume

Radius of the vessel

Vessel length

Radius of the vessel

Choosing the correct blood pressure cuff size is important because:

If affects heart rate

It changes the turbulence intensity

It influences measurement accuracy

It improves oxygen delivery

It influences measurement accuracy

Which of the following is NOT correct regarding facilitated diffusion?

It moves substances down their concentration gradient

It requires energy to move substances

It requires the use of proteins in the membrane

All are correct statements regarding facilitated diffusion

It requires energy to move substances

Which of the following are types of transport across the cell membrane?

Active transport

Facilitated diffusion

Simple diffusion

All of the above

All of the above

How is glucose transported across the cell membrane?

Carrier-mediated facilitated diffusion

Simple diffusion

Osmosis

None of the above

Carrier-mediated facilitated diffusion

This cell junction is abundant in tissues subjected to great mechanical stress.

Tight junctions

Gap junctions

Desmosomes

None of the above

Desmosomes

Which of the following describes the plasma membrane?

A phospholipid bilayer surrounding the cell

A triple-layered membrane that surrounds the nucleus of the cell

A membrane composed of only cholesterol molecules

A double layer of protein enclosing the plasma

A phospholipid bilayer surrounding the cell

Which of the following is not a part of the cell membrane?

Phospholipids

Nucleic acids

Proteins

Lipids

Nucleic acids

Mechanical equilibrium requires:

Equal forces in all directions

Zero net force and zero net torque

No acceleration

Balance in the X-axis

Zero net force and zero net torque

Which one of the following is a scalar quantity?

Acceleration

Temperature

Displacement

Velocity

Temperature

A wide base of support and low center of gravity lead to:

Weak posture

Unstable movement

Better stability

Joint collapse

Better stability

Methylation is a key mechanism in:

Digestion

Translation

Cellular respiration

Epigenetic regulation

Epigenetic regulation

Which enantiomer of glucose is metabolized by human cells?

D-glucose

L-glucose

Neither

Both D- and L-glucose

D-glucose

Which of the following is an example of an organic molecule?

C6 H12 O6

CO2

NaCl

H2O

C6 H12 O6

Hyperventilation affects blood pH by:

Decreasing CO2 and raising pH

Decreasing HCO3-

Increasing CO2 and lowering pH

Increasing H+

Decreasing CO2 and raising pH

Which functional group forms the ester linkage in fats?

Methyl

Carboxyl and hydroxyl

Phosphate

Hydroxyl

Carboxyl and hydroxyl

Acetylation involves adding which group?

-COCH3

-CH3

-OH

-PO₄²⁻

-COCH3

Which functional group increases the solubility of organic molecules in water?

Sulfhydryl (-SH)

Hydroxyl (-OH)

Carboxyl (-COOH)

Methyl (-CH3)

Hydroxyl (-OH)

Nucleic acids are build from:

Nucleotides

Peptides

Fatty Acids

Monosaccharides

Nucleotides

The pH of a sample of blood is 7.4, while gastric juice is pH 1.4. The blood sample has [H+] than the gastric juice.

5.29 times lower

one million times lower

6,000 times lower

6 times lower

one million times lower

Which of the following cannot freely diffuse through the cell membrane?

Oxygen

Glucose

CO2

All of the above can pass through the membrane freely

Glucose

Which of the following is true regarding osmosis?

It is the diffusion of water through a semi-permeable membrane

It is a passive process

Both are true regarding osmosis

Both are true regarding osmosis

Which of the following statements is correct regarding diffusion?

The molecular weight of a substance does not affect the rate

The greater the concentration gradient, the faster the rate

The lower the temperature, the faster the rate

The rate in independent of temperature

The greater the concentration gradient, the faster the rate

Which of the following cell types have nuclei?

Viruses

Bacteria

Eukaryotes

Prokaryotes

Eukaryotes

The cell membrane is selectively permeable. What does this mean for the cell?

All materials can enter and leave the cell

Only certain materials can enter and leave the cell

Neither are correct

Only certain materials can enter and leave the cell

How does the exchange of oxygen and carbon dioxide occur across the cell membrane?

Cell-mediated diffusion

Facilitated diffusion

Osmosis

Simple diffusion

Simple diffusion

According to Pascal's Principle, what happens to the pressure generated by the ventricles during contraction?

It is concentrated only at the valve openings

It is lost due to turbulence in the chamber

It is distributed uniformly to the entire volume of blood in the chamber

It bypasses the chamber and flows directly into the arteries

It is distributed uniformly to the entire volume of blood in the chamber

The buoyant force on an object submerged in a fluid is equal to the:

Volume of the object

Weight of the object

Mass of the displaced fluid

Weight of the displaced fluid

Weight of the displaced fluid

What kind of flow is characterized by smooth streamlines?

Turbulent

Viscous

Laminar

Irregular

Laminar

In heart failure, which of the following is commonly observed?

Increased ejection fraction

Decreased preload

Reduced cardiac output

Enhanced contractibility

Reduced cardiac output

Which of the following best describes the role of the AV node in cardiac conduction?

Terminates the electrical cycle during repolarization

Delays conduction to allow ventricular filling

Rapidly spread impulses through ventricles

Initiates the heartbeat and controls contraction rate

Delays conduction to allow ventricular filling

Atrial systole occurs during diastole

True

False

True

Which of the following cardiac structures is responsible for initiating the electrical impulse in the heart?

AV node

SA node

Bundle of His

Purkinje fibers

SA node

Why is blood flow slower in capillaries despite smaller diameter?

Capillaries are longer

Capillaries have high blood pressure

Capillaries constrict more

Total cross-sectional area is large

Total cross-sectional area is large

What happens to Na+ channels during the absolute refractory period?

They are fully activated

They have reset to neutral

They are inactive

They remain open

They are inactive

If EDV = 120 mL and ESV =50 mL, what is the stroke volume?

50 mL

70 mL

90 mL

60 mL

70mL

(SV = EDV − ESV = 120 − 50)

Xanthine derivatives like theophylline are beneficial in:

Bone growth

Bronchodilation

Visual acuity

Skin elasticity

Bronchodilation

Carbohydrates are classified based on:

The number of carbon atoms

Their amino acid content

Their degree of polymerization

Their solubility in water

Their degree of polymerization

Which term refers to the sum of heat content in a system?

Free energy

Entropy

Work

Enthalpy

Enthalpy

Which best describes catabolism?

Breakdown of molecules to release energy

Storage of genetic information

Energy-consuming synthesis

Transport of nutrients

Breakdown of molecules to release energy