Exam #1 Flashcards
Describe oxidative phosphorylation.
Process that occurs in the mitochondria. Oxidative phosphorylation is when energy is produced from carbohydrates, fats, and proteins and is transferred to ATP. ATP is most efficient in the presence of oxygen (aerobic metabolism) since oxygen provides the cell with a much more powerful method for extracting energy from the food molecules. When generating ATP through the anaerobic process, glycolysis is used. Glycolysis occurs outside of the mitochondria and is not as efficient as aerobic metabolism. Glycolysis makes 1 ATP while aerobic metabolism makes 3 ATP.
What causes hydrostatic pressure? Where is the fluid in the blood vessels moving?
Hydrostatic pressure is caused by the pushing of fluid across a semipermeable cell membrane. In blood vessels, hydrostatic pressure is caused by the pumping action of the heart. When this occurs in the blood vessels, the fluid is leaving the blood vessel and entering into the interstitial fluid.
What causes colloid osmotic pressure? Where is the fluid in the blood vessels moving?
Colloid osmotic pressure is primarily due to plasma proteins in the blood, specifically albumin. If plasma proteins are lost or if production is decreased, osmotic pressure will decrease and fluid will remain in the interstitial space instead of being returned to the capillaries. Plasma proteins are too large to easily cross the capillary walls and the effect of this is that it helps keep fluid from leaking out of the capillaries. Osmotic pressure tends to pull fluid into the capillaries.
Differentiate the three types of active mediated transport.
Uniport is when a single molecule moves in one direction
Symport is when two molecules move simultaneously in the same direction
Antiport is when two molecules move simultaneously in opposite directions
Describe the Na K pump.
The Na K pump is an example of an antiport system. It is an active transport that moves 3 molecules of Na+ out of the cell and 2 molecules of K+ into the cell for every ATP molecule expended. Both Na+ and K+ are moving against the concentration gradient.
*An antiport system is when 2 molecules move simultaneously in opposite directions (i.e. Na+ and K+). When cell is at rest, Na+ is mostly outside the cell while K+ is inside of the cell. Upon activation, Na+ moves inside the cell while K+ leaves. The Na+ K+ pump helps get the cell back to its resting state.
What transport systems are examples of endocytosis?
Pinocytosis and phagocytosis are two forms of endocytosis.
Endocytosis moves molecules into the cell by enfolding the substance into the plasma membrane and forming a vesicle that moves into the cell.
Pinocytosis involves ingestion of fluids or cellular drinking.
Phagocytosis is ingestion of large particles such as bacteria or cellular eating
Describe the ionic basis of the action potential.
Rest- At rest the inside of the cell is negatively charged (-70 mV)
- Stimulate- Na+ enters the cell until reaching threshold (-55 mV)
- Depolarization- cell membrane potential increases to (+30 mV) as more Na+ enters cell.
- Na+ gates close and K+ gates slowly open, completing depolarization.
- Repolarization begins when the Na+ gates close and K+ gates open. It is complete once the K+ gates close.
- Hyperpolarization- “Overshoot” (~ -90 mV) occurs, because exceeding the resting potential prevents the cell from simultaneously receiving other stimuli.
- Return to Rest- The cell returns to resting membrane potential (-70 mV) by pumping Na+ out and K+ into the cell.
Differentiate absolute and relative refractory periods.
Absolute refractory period: occurs during most of the action potential (depolarization and repolarization) the cell is not able to respond to another stimulus.
Relative refractory period: occurs towards the end of repolarization, when the K+ gates are beginning to close, a stronger than normal stimulus can cause a reaction.
What cells reproduce through mitosis?
Somatic cells, which are all cells except sperm and egg cells
What cells reproduce through meiosis?
Sperm and egg cells
What is the mutant allele (A or a) in autosomal dominant disorders? Autosomal recessive disorders?
In autosomal recessive disorders the mutant or recessive allele is “a”. In this disorder both genes have to be abnormal for the disorder to be expressed.
*In autosomal dominant disorders the abnormal allele is dominant “A” over the normal allele “a”.
What are clinical manifestations of neurofibromatosis?
Neurofibromatosis is an autosomal dominant disorder where cell growth in the nervous system is affected causing tumors to form on nervous tissue, including the brain, spinal cord and nerves. Symptoms typically appear in early childhood in the most common form and the telltale sign is the presence of coffee-colored birthmarks called “cafe-au-lait” spots. After puberty tumors tend to develop under the skin and sometimes internally. Mild symptoms may include hearing loss, vision loss, learning impairment, severe pain, and heart and blood vessel complications. Severe disability may occur due to nerve compression by the tumors. Other features can include high BP, curvature of the spine, speech problems and the development of epilepsy.
What are clinical manifestations of Marfan Syndrome?
Marfan Syndrome is when too much of the protein fibrillin is produced. Symptoms include skeletal changes such as very long arms, legs, fingers, toes. Individuals may also have a deeply depressed sternum or scoliosis.
Which diseases are autosomal dominant, autosomal recessive, and X-linked?
Autosomal Dominant disorders- Huntington Disease, Neurofibromatosis, Marfan Syndrome.
Autosomal Recessive disorders- Sickle Cell Anemia, Cystic Fibrosis, Phenylketonuria (PKU)
X-Lined disorders- Duchenne Muscular Dystrophy, Hemophilia
What does being a “carrier” or having the “trait” mean?
Being a carrier/having the trait means that you yourself do not have the disorder but you have the ability to pass it on to your offspring.
What abnormality is present in sickle cell anemia? In hemophilia?
Sickle cell anemia arises when there is a mutation in a gene that tells the body to make hemoglobin; hemoglobin S is produced. RBCs become rigid, sticky, and shaped like crescent moons when oxygen levels are decreased. This causes clumps in the blood vessels that block blood and oxygen from circulating throughout the body.
Hemophilia is an X-linked disorder that causes low levels of clotting factors. This provokes excessive/prolonged bleeding.
What are the clinical manifestations for cystic fibrosis?
Common symptoms of those with CF are include chronic coughing (dry or with phlegm), recurring chest colds, wheezing and SOB, frequent lung infections like pneumonia or bronchitis, and poor growth or weight gain even when having a good appetite and constipation.
What is the treatment for phenylketonuria (PKU)?
People with PKU must follow a low protein diet throughout their lives as their treatment.
*Patients with PKU must follow a low protein diet as the gene that codes the enzyme responsible for breaking down the amino acid, phenylalanine, is mutated. This causes a build up of phenylalanine that can lead to multiple health problems including mental retardation.
What are the clinical manifestations of Duchenne muscular dystrophy?
Duchenne muscular dystrophy is characterized by progressive muscle weakness. Signs and symptoms usually begin when the child reaches walking age and include frequent falls, difficulty getting up from a lying or sitting position, large calf muscles, walking on toes, waddling gait, trouble keeping balance, muscle pain/stiffness, and learning disabilities.
What is the genetic abnormality in Down Syndrome, Turner Syndrome, and Klinefelter Syndrome?
Down: trisomy, three chromosome 21’s
Turner: monosomy X or the presence of a single X chromosome instead of two resulting in 45 chromosomes in these females
Kline: results in males with two X chromosomes and one Y, for a total of 47 chromosomes
What are the clinical manifestations of Turner Syndrome and Klinefelter Syndrome?
Kleinfelter’s is XXY (two X chromosomes) and Turner’s is XO (one X chromosome instead of two)
*The clinical manifestations of Turner’s syndrome include females having a wide carrying angle of the arms, low hairlines and webbing of the neck, ears being slightly lower than normal, eyes having a downward tilt, jawbones slightly less prominent, and a droop to one or both eyes.
Klinefelter’s syndrome can have clinical manifestations of a male appearance with female characteristics, like wide hips, enlarged breasts, high voice, and sparse body hair. The males will also be sterile with small testicles.
Give examples of atrophy, hyperplasia, metaplasia, dysplasia.
Atrophy - a decrease in the size of cells. An example of physiologic atrophy is the shrinking of the thymus gland as childhood progresses. An example of pathologic atrophy is the shrinking of skeletal muscle when a limb is placed in a cast due to immobilization.
Hyperplasia - an increase in the number of cells. An example of physiologic hyperplasia is when part of the liver is removed and the remaining cells regenerate. An example of pathologic hyperplasia is the enlargement of the prostate gland (benign prostatic hyperplasia) which can cause urinary difficulties in men.
Metaplasia - the reversible replacement of one mature cell type by a another, sometimes less mature, cell type. This change occurs due to an irritant in the environment. For example, Barrett’s metaplasia occurs in the lower esophagus due to irritation from acid reflux. When the acid reflux is controlled and the lower esophagus is free from the irritation of stomach acid, the metaplasia can be reversed.
Dysplasia - the abnormal change in in size, shape, and organization of mature cells that can be preceded by hyperplasia or metaplasia. Common sites that are affected include the cervix and the respiratory tract. For example, a pap smear is done to determine if cervical cells have changed or become dysplastic.
What is occurring at the cellular level when a patient has hypoxia?
There is a decrease in ATP production, causing sodium and potassium to remain in the cell. Which can cause disruption in the cellular metabolic process ultimately leading to cell death.
- Cell death occurs because calcium is being accumulated and this causes enzymes to activate.
What is occurring at the cellular level when free radicals are present?
- )Destruction of polyunsaturated fats.
- )Protein alterations that cause transport mechanisms in the cell membrane to fail.
- ) There is a reduction in protein synthesis
- ) Mitochondrial damage, causing calcium to be out into the cytosol which can lead to cell death.
* The cell’s plasma membrane is damaged, causing increased permeability.
