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What is the study of biological function?
What is the study of biological function?
Physiology
What is the emphasis in the study of physiology?
What is the emphasis in the study of physiology?
Mechanisms
The study of physiology only involves human bodies.
The study of physiology only involves human bodies.
False
What is the application of knowledge of human physiology in the management of dysfunctions and diseases in human beings?
What is the application of knowledge of human physiology in the management of dysfunctions and diseases in human beings?
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What is the key subject in medicine?
What is the key subject in medicine?
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What is the basis of understanding disease processes and the insight into disease management and prevention?
What is the basis of understanding disease processes and the insight into disease management and prevention?
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The Nobel Prize in Physiology and Medicine is awarded for groundbreaking discoveries in the health sector.
The Nobel Prize in Physiology and Medicine is awarded for groundbreaking discoveries in the health sector.
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What is the foundation of medical practice?
What is the foundation of medical practice?
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What did S. Singer and G. Nicolson propose in 1972?
What did S. Singer and G. Nicolson propose in 1972?
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What percentage of the molecules in the membrane are lipids?
What percentage of the molecules in the membrane are lipids?
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What percentage of the lipids are phospholipids?
What percentage of the lipids are phospholipids?
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Fatty acids can only contain an even number of carbon atoms.
Fatty acids can only contain an even number of carbon atoms.
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What are fatty acid chains that contain no double bonds called?
What are fatty acid chains that contain no double bonds called?
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What are fatty acid chains that contain one or more double bonds called?
What are fatty acid chains that contain one or more double bonds called?
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Glycolipids are molecules that contain only carbohydrate.
Glycolipids are molecules that contain only carbohydrate.
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What are glycolipids that are attached to the amino alcohol sphingosine called?
What are glycolipids that are attached to the amino alcohol sphingosine called?
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Glycosphingolipids are found in greatest amounts in muscle tissue.
Glycosphingolipids are found in greatest amounts in muscle tissue.
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Glycosphingolipids are antigenic.
Glycosphingolipids are antigenic.
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Glycosphingolipids are only found in human cells.
Glycosphingolipids are only found in human cells.
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The carbohydrate portion of a glycolipid serves as a cell surface receptor for cholera and tetanus toxins.
The carbohydrate portion of a glycolipid serves as a cell surface receptor for cholera and tetanus toxins.
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What are prostaglandins, thromboxanes, and leukotrienes collectively known as?
What are prostaglandins, thromboxanes, and leukotrienes collectively known as?
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Eicosanoids are produced in large amounts in specialized glands.
Eicosanoids are produced in large amounts in specialized glands.
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What is phosphatidylinositol cleaved into?
What is phosphatidylinositol cleaved into?
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Diacylglycerol and inositol trisphosphate act as second messengers.
Diacylglycerol and inositol trisphosphate act as second messengers.
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Cortisol blocks the action of phospholipase A2.
Cortisol blocks the action of phospholipase A2.
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Aspirin blocks the action of cyclooxygenase.
Aspirin blocks the action of cyclooxygenase.
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NSAIDs block the action of leukotriene biosynthesis.
NSAIDs block the action of leukotriene biosynthesis.
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Cholesterol molecules constitute about 20% of the membrane lipids.
Cholesterol molecules constitute about 20% of the membrane lipids.
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Cholesterol stiffens the membrane.
Cholesterol stiffens the membrane.
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Steroid hormones are derived from cholesterol in animals.
Steroid hormones are derived from cholesterol in animals.
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Hormones like testosterone and estradiol are involved in the development of sexual characteristics.
Hormones like testosterone and estradiol are involved in the development of sexual characteristics.
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Proteins constitute about 75% of the membrane weight.
Proteins constitute about 75% of the membrane weight.
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What are proteins that pass through the membrane called?
What are proteins that pass through the membrane called?
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Most integral proteins are glycoproteins.
Most integral proteins are glycoproteins.
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Peripheral proteins do not protrude into the phospholipid layer.
Peripheral proteins do not protrude into the phospholipid layer.
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What is an example of a peripheral protein that is bound to the spectrin network?
What is an example of a peripheral protein that is bound to the spectrin network?
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What is the protein that anchors the anion exchanger to the spectrin network?
What is the protein that anchors the anion exchanger to the spectrin network?
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What is the predominant protein of the skeletal protein lattice?
What is the predominant protein of the skeletal protein lattice?
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What is the name for chemical signals that cells use to communicate?
What is the name for chemical signals that cells use to communicate?
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All signaling molecules can enter the target cell.
All signaling molecules can enter the target cell.
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Second messenger systems are triggered by the binding of a messenger to a surface receptor.
Second messenger systems are triggered by the binding of a messenger to a surface receptor.
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Proteins can function as enzymes.
Proteins can function as enzymes.
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Channel proteins are always open.
Channel proteins are always open.
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What are the three types of stimuli that channel protein gates respond to?
What are the three types of stimuli that channel protein gates respond to?
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Pumps actively transport ions across the membrane.
Pumps actively transport ions across the membrane.
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Carriers transport substances against their concentration gradients.
Carriers transport substances against their concentration gradients.
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Membrane structure makes them selective about which molecules can pass through them.
Membrane structure makes them selective about which molecules can pass through them.
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The hydrophobic interior of the lipid bilayer makes membranes impermeable to polar molecules.
The hydrophobic interior of the lipid bilayer makes membranes impermeable to polar molecules.
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What are the two basic processes of transport through the cell membrane?
What are the two basic processes of transport through the cell membrane?
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Lipid solubility is a factor that determines how rapidly a substance diffuses through the lipid bilayer.
Lipid solubility is a factor that determines how rapidly a substance diffuses through the lipid bilayer.
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The term permeable means that a structure allows the passage of substances through it; impermeable means that a structure doesn't allow the passage of substances.
The term permeable means that a structure allows the passage of substances through it; impermeable means that a structure doesn't allow the passage of substances.
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Plasma membranes permit all substances to pass through them at the same rate.
Plasma membranes permit all substances to pass through them at the same rate.
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The lipid bilayer portion of the membrane is permeable to polar molecules like glucose.
The lipid bilayer portion of the membrane is permeable to polar molecules like glucose.
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Simple diffusion is the only form of transport across cell membranes that is not carrier-mediated.
Simple diffusion is the only form of transport across cell membranes that is not carrier-mediated.
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Simple diffusion requires metabolic energy.
Simple diffusion requires metabolic energy.
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Facilitated diffusion occurs down an electrochemical gradient.
Facilitated diffusion occurs down an electrochemical gradient.
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Facilitated diffusion requires metabolic energy.
Facilitated diffusion requires metabolic energy.
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Facilitated diffusion uses a membrane carrier and exhibits all the characteristics of carrier-mediated transport.
Facilitated diffusion uses a membrane carrier and exhibits all the characteristics of carrier-mediated transport.
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Simple diffusion is a type of carrier-mediated transport.
Simple diffusion is a type of carrier-mediated transport.
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Mediated transport is much more rapid than other molecules of similar molecular weight and lipid solubility.
Mediated transport is much more rapid than other molecules of similar molecular weight and lipid solubility.
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The transport rate of mediated transport is not affected by the concentration of the transported compound.
The transport rate of mediated transport is not affected by the concentration of the transported compound.
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Active transport requires energy.
Active transport requires energy.
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Passive transport requires energy.
Passive transport requires energy.
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Primary active transport uses ATP.
Primary active transport uses ATP.
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Secondary active transport uses ATP directly.
Secondary active transport uses ATP directly.
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Active transport allows the concentration of substrates against concentration or electrochemical potential gradients.
Active transport allows the concentration of substrates against concentration or electrochemical potential gradients.
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Active transport moves solutes down an electrochemical potential gradient.
Active transport moves solutes down an electrochemical potential gradient.
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The Na+-K+ ATPase pump moves 3 sodium ions out of the cell and 2 potassium ions into the cell.
The Na+-K+ ATPase pump moves 3 sodium ions out of the cell and 2 potassium ions into the cell.
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The Na+-K+ pump maintains a high intracellular concentration of sodium ions.
The Na+-K+ pump maintains a high intracellular concentration of sodium ions.
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Secondary active transport relies on the electrochemical gradient created by primary active transport.
Secondary active transport relies on the electrochemical gradient created by primary active transport.
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Cotransport occurs when two solutes move in opposite directions across the membrane.
Cotransport occurs when two solutes move in opposite directions across the membrane.
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Countertransport occurs when two solutes move in the same direction across the membrane.
Countertransport occurs when two solutes move in the same direction across the membrane.
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Cardiac glycosides inhibit the Na+-K+ pump.
Cardiac glycosides inhibit the Na+-K+ pump.
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Osmosis is the flow of water across a semipermeable membrane from an area of high solute concentration to an area of low solute concentration.
Osmosis is the flow of water across a semipermeable membrane from an area of high solute concentration to an area of low solute concentration.
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A semipermeable membrane allows the passage of both water and solutes.
A semipermeable membrane allows the passage of both water and solutes.
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The presence of solute decreases the chemical potential of water.
The presence of solute decreases the chemical potential of water.
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A solution with a higher solute concentration has a higher chemical potential of water.
A solution with a higher solute concentration has a higher chemical potential of water.
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Decreasing the chemical potential of water in a solution lowers vapor pressure, lowers the freezing point, and lowers the boiling point.
Decreasing the chemical potential of water in a solution lowers vapor pressure, lowers the freezing point, and lowers the boiling point.
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Osmolarity refers to the total solute concentration of a solution.
Osmolarity refers to the total solute concentration of a solution.
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A 1 milliosmolar solution contains 1000 milliosmoles of solute particles per liter.
A 1 milliosmolar solution contains 1000 milliosmoles of solute particles per liter.
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The normal osmolarity of intracellular and extracellular fluid is approximately 300 mOsm.
The normal osmolarity of intracellular and extracellular fluid is approximately 300 mOsm.
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What does the equation $\pi = g \times RT \times C$ represent?
What does the equation $\pi = g \times RT \times C$ represent?
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Study Notes
Physiology
- Physiology is the study of biological function, focusing on how the body works from the cellular level to the organismal level.
- The emphasis is on mechanisms and cause-and-effect sequences.
- It examines how living organisms function.
- Human physiology specifically studies the functions of cells, organs, and organ systems in the human body.
- Medical physiology applies human physiology knowledge to manage dysfunctions and diseases in human beings.
Membrane Structure
- In 1972, S. Singer and G. Nicolson revised the fluid mosaic model of membrane structure.
- The model suggests that globular proteins are embedded in the lipid bilayer with nonpolar segments interacting with the interior portion of the bilayer and polar portions protruding from the membrane surface.
- Membrane lipids are predominantly phospholipids.
- They form a bi-layer with hydrophilic phosphate-containing heads facing the water and hydrophobic tails facing the center of the membrane.
- Fatty acids are monocarboxylic acids that usually contain an even number of carbon atoms.
Glycolipids
- Glycolipids are molecules containing both carbohydrate and lipid components.
- Like phospholipids, they are essential components of all membranes, but are concentrated in nerve tissue.
- They are found in the outer leaflet of the plasma membrane and play a role in cellular interactions, growth, and development.
- Glycolipids are antigenic and serve as a source of blood group antigens, embryonic antigens, and some tumor antigens.
Prostaglandins and Related Compounds
- Prostaglandins, thromboxanes, and leukotrienes are collectively known as eicosanoids.
- They originate from polyunsaturated fatty acids with 20 carbons.
- Prostaglandins are potent compounds affecting both physiological and pathological responses, acting locally.
- They are produced in small amounts in various tissues rather than specialized glands.
Membrane Lipids
- Lipids are about 98% of membrane molecules, 75% of which are phospholipids.
- Amphiphilic molecules arrange into a bilayer.
- Hydrophilic phosphate heads face water. Hydrophobic tails avoid water and face the center of the membrane.
Cholesterol
- Cholesterol molecules found among fatty acid tails constitute about 20% of membrane lipids.
- Cholesterol interacts with phospholipids, making the membrane less fluid in spots.
- High concentrations conversely increase fluidity.
Membrane Proteins
- Proteins are only about 2% of membrane molecules by weight—however, they represent about 50% by mass and are larger than membrane lipids.
- Some proteins, called integral proteins, pass entirely through the membrane.
- Other proteins, called peripheral proteins, do not protrude into the lipid bilayer but adhere to the face of the membrane.
- Many integral proteins are glycoproteins with oligosaccharides on the outer membrane layer.
- Functions include receptors, second messenger systems, and enzymes.
Channel Proteins
- Channel proteins are integral proteins with pores allowing water and hydrophilic molecules to pass through.
- These gates respond to various stimuli such as chemical messengers, electrical potential changes, and physical stress (e.g., stretch or pressure)
Transport of Substances Through the Cell Membrane
- Membranes are selective about what passes through.
- The lipid bilayer is impermeable to polar molecules.
- Transport can be through diffusion or active transport.
- Diffusion depends on lipid solubility.
Membrane Permeability
- Permeability refers to a structure allowing substance passage.
- Plasma membranes exhibit selective permeability, allowing some substances to pass more easily than others.
- The lipid bilayer is permeable to nonpolar, uncharged molecules.
- It is impermeable to ions and large, uncharged polar molecules.
- It's slightly permeable to small, uncharged polar molecules like water and urea.
Simple Diffusion
- Occurs down an electrochemical gradient.
- Does not require metabolic energy.
- Flux (flow) depends on concentration gradient, partition coefficient, diffusion coefficient, membrane thickness, and surface area.
Facilitated Diffusion
- Like simple diffusion, it occurs down an electrochemical gradient.
- However, it employs a membrane carrier protein exhibiting saturation and competition.
Active Transport
- Moves substances against electrochemical gradients.
- Requires metabolic energy—typically ATP.
- Primary active transport directly uses ATP, and secondary active transport leverages energy from primary active transport electrochemical gradients.
Osmosis
- Osmosis is the movement of water across a semipermeable membrane from a lower solute concentration to a higher solute concentration.
- Osmosis occurs because solute concentration gradients alter the chemical potential of water, affecting osmosis.
Osmolarity
- Osmolarity is a measure of the total solute particle concentration.
- The normal osmolarity of intracellular and extracellular fluid is approximately 300 mOsm.
Calculating Osmotic Pressure
- Van't Hoff's law calculates osmotic pressure.
- Variables include concentration (C), gas constant (R), absolute temperature (T), and the number/factor of particles (g)
Vesicular Transport
- Large particles, fluids, or molecules move through vesicles.
- Endocytosis brings matter into a cell.
- Exocytosis releases matter from a cell.
- Endocytosis types include phagocytosis, pinocytosis, and receptor-mediated endocytosis.
Tonicity
- A hypotonic solution has a lower solute concentration than the interior of a cell, causing water to flow into the cell, potentially bursting it (hemolysis).
- A hypertonic solution has a higher solute concentration than the interior of a cell, causing water to flow out of the cell, potentially shrinking it (crenation).
- An isotonic solution has an equal solute concentration, resulting in no net water movement.
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Description
Test your knowledge on the fundamentals of physiology, focusing on cellular and organism functions. This quiz also covers the fluid mosaic model of membrane structure and the role of phospholipids. Perfect for students studying human physiology and cellular biology.
