Lecture 2-Exam 1 Flashcards
The following organic elements make up more than 97% of the mass of the human body:
Carbon, hydrogen, o2, nitrogen, sulfur and phosphorous
Additional element calcium which is found in what?
bones, teeth, cartilage and makes up an additional 2%
The additional 2-3% is made up of what? List the ones we care about?
Inorganic elements: iron, zinc and copper
What are the inorganic elements considered?
Micronutrients because they are needed for health but in minute quantities
What are the nutritionally essential transition metals?
iron (Fe), manganese (Mn), zinc (Zn), cobalt (Co), Copper (Cu), nickel (Ni), molybdenum (Mo), vanadium (V), and chromium (Cr).
Can transition metals be toxic? Explain?
- While nutritionally essential, several transition metals may be harmful if present in the body in excess
- The body makes sure there is strict control over both the uptake and excretion of transition metal ions.
What is an example of reguation of transition metals?
hepcidin system for regulation of iron to avoid its accumulation to damaging levels.
◦ The appropriate regulation of hepcidin expression is dependent on the ability of the liver to sense intracellular and extracellular iron and relay these signals to the hepatocyte nucleus where hepcidin expression can be appropriately modulated to maintain homeostasis
What do symptoms of acture metal poisoning by heavy metals or transitional metals include?
include abdominal pain, vomiting, muscle cramps, confusion, and numbness
What is the treatments of transition metal toxicity?
Treatments include administration of metal chelating agents, diuretics, or—should kidney function be compromised—hemodialysis
Hepcidin:
* What type of molecule?
* Is Iron excreted? Explain the process
- Hepcidin is hormone peptide produced in the liver
- Iron is NOT excreted. The lack of a regulated iron excretory mechanism means that body iron balance is controlled at the level of absorption from the diet.
How is iron absorption regulated? Explain how it works
Iron absorption is regulated by hepcidin. Hepcidin also controls iron release from cells that recycle or store iron, thus regulating plasma iron concentrations.
- Hepcidin exerts its effects through its receptor, the cellular iron exporter _
- Explain why hepcidin is an important regulator
- Missing word: Ferroportin
- Important regulators of hepcidin, and therefore of systemic iron homeostasis, include plasma iron concentrations, body iron stores, infection and inflammation, and erythropoiesis.
What happens when hepcidin bind to ferroportin receptor?
- Binds to the ferroportin receptor, degrades ferroportin and traps the iron in the intestinal cells
- Ferroportin is a transmembrane protein that transports iron from the inside of a cell to the outside of the cell. Ferroportin is the only known iron exporter
Explain where plasma iron goes
What is the second most abundant metal on earth, is favorable for its oxidation- reduction characteristics?
Iron
What are components involved in energy transfer?
Major constituent of hemoglobin, myoglobin, and many other enzymes
80% of body iron is destined for what?
for bone marrow uptake (hemopoiesis)
What is ferritin and transferrin
Ferritin- an intracellular Fe3+ storage protein-> can look at in labs
* Even though its intracellular, its levels in peripheral blood provide a noninvasive measure of iron overload
* Hemochromatosis
Transferrin – an extracellular Fe3+ transport protein
What is Iron deficiency anemia
insufficient levels of iron affects the ability to produce hemoglobin, thus limiting the amount of functional red blood cells that can carry oxygenated blood around the body
What are the symptoms of iron deficiency?
- Extreme fatigue
- Weakness
- Pale skin
- Cold hands and feet
- Inflammation or soreness of your tongue
- Brittle nails
- Unusual cravings for non-nutritive substances, such as ice, dirt or starch (pica)
- Poor appetite, especially in infants and children with iron deficiency anemia
- Most iron is found in _ , the rest is stored as _ .
- Ferritin levels are useful to do what?
Most iron is found in hemoglobin, the rest is stored as ferritin. Ferritin levels are useful to assess body iron stores
Iron needs a protein, called what? What does it do?
Iron needs a protein, called transferrin, to travel in the blood. Blood iron levels represent the balance between dietary intake and iron losses (menses, loss in stools, etc.).
Iron binding capacity is calculated from what? What is it used for?
blood transferrin levels and is expressed as a percentage. It is used to distinguish the various types of anemia.
The four most frequent iron-related tests are what?
- serum iron - measures iron levels in serum; represents iron that is almost completely bound to transferrin;
- transferrin - measures levels of the iron carrier;
- total iron binding capacity (TIBC) - measures the transferrin capacity to bind iron
- serum ferritin - measures the body’s ability to store iron.
What is hemosiderosis?
accumulation of excess hemosiderin (insoluble compound containing up to 40% iron)
Hemosiderosis can result from?
- Direct bleeding into the tissues that is followed by breakdown of red blood cells and release of iron to the tissues
- Destruction of red blood cells within the blood vessels, leading to release of iron into the blood followed by accumulation of iron inside the kidneys as the kidneys filter waste from the blood
- What are site of hemosiderosis?
- Excessive iron absorption that causes hemosiderosis is a condition called what?
- Lungs and kidneys
- Hemochromatosis
Hemochromatosis:
* What type of disease? How common?
* What is hyperabsorped?
* What is serum level is high? What is the treatment?
* What are symptoms?
From the picture of hemochromatosis:
* More common in who?
* Increased what?
* Leads to what?
* What is treatment?
- More common in males and age presentation of 50 years
- Increased intestinal iron absorption
- Leads to free radicle injury and iron deposition in paranchymal organs-> fibrosis (organ damage)
- Treatment: Regular phlebotomy and iron chelator
Oxygen must be delivered from lungs to peripheral tissues. How is this carried out?
This function is carried out by myoglobin and hemoglobin
What is myoglobin and hemoglobin?
- Myoglobin: an iron- and oxygen-binding protein found in the cardiac and skeletal muscle tissue of vertebrates in general and in almost all mammals
- Hemoglobin: a tetrameric protein of erythrocytes, it interacts in a cooperative fashion that enables this transporter to offload a high proportion of bound O2 in peripheral tissues while simultaneously retaining the capacity to bind it efficiently in the lungs
- Both myoglobin and hemoglobin contain _
- What is heme?
- Both myoglobin and hemoglobin contain heme
- Heme is an iron-containing cyclic tetrapyrrole consisting of four molecules of pyrrole linked by methyne bridges
Iron is in the form of _ on a heme molecule
Fe2+
- Hemoglobin aids in what?
- What are some genetic disorders?
- Cyanide and carbon monoxide (CO) kill because why?
- transporting CO2 to the lungs for disposal
- Genetic disorders sickle cell and thalassemia’s
- Cyanide and carbon monoxide (CO) kill because they disrupt the physiologic function of the heme proteins cytochrome oxidase and hemoglobin
- Hemoglobin has _ polypeptide chains and _ oxygen binding sites.
- Myoglobin is a _ polypeptide chain with _ oxygen binding site, which results in the different binding kinetics of the two proteins to oxygen.
- Hemoglobin has four polypeptide chains and four oxygen binding sites.
- Myoglobin is a single polypeptide chain with one oxygen binding site, which results in the different binding kinetics of the two proteins to oxygen.
Myoglobin binds to oxygen how? How does this compare to hemoglobin?
Myoglobin does so noncooperatively, unlike hemoglobin which binds to oxygen cooperatively as a result of its tetrameric nature
What are the graph shapes of myoglobin and hemoglobin? Why is this?
- As a result, myoglobin’s oxygen saturation curve is hyperbolic. Myoglobin exhibits a higher affinity for oxygen than hemoglobin. Therefore, it is very efficient at extracting oxygen from the blood and storing it
- Hemoglobin displays a sigmoid-shaped curve due to its cooperative binding.
label
What is:
* Myoglobinuria
* Anemias
* Thalassemias
- Myoglobinuria – following crush injury to skeletal muscle followed by renal damage, myoglobin may appear in urine
- Anemias – reductions in the number of red blood cells (folic acid or vitamin B 12 deficiencies) or hemoglobin in blood, (may reflect iron deficiency)
- Thalassemias - partial or total absence of one or more α or β chains of hemoglobin, 3 common, α chain (α thalassemias) or β chain (β thalassemias) can be affected
Glycated hemoglobin is what?
is a form of hemoglobin that is chemically linked to a sugar. Most monosaccharides, including glucose, galactose and fructose, spontaneously bond with hemoglobin when present in the bloodstream
Glycated Hemoglobin – HbA1c provides what?
valuable information for management of diabetes mellitus
Glycated hemoglobin (A1C) or HgbA1c, is an effective and objective retrospective marker of what?
blood glucose control over the previous 3 months. The A1C value is determined by the 3-month lifespan of a red blood cell
What is the normal value ranges of Glycated Hemoglobin – HbA1c
4-5.5
Vitamins:
* Essential or not?
* Some can be what?
* Most vitamins need to be what?
* What are the two types of vitamins?
- Functionally essential
- Some can be synthesized by endogenous pathways, unusual conditions of precursor availability (vitamin D and niacin)
-
Most vitamins need to be supplied in the diet
* Since vitamins are abundant and only required in a small amount, usually only see deficiency in malnutrition cases - Vitamins are water soluble or fat soluble
Water soluble vitamin:
* What are examples? What are they precursors of?
B vitamins:
* folate, thiamine (B1), riboflavin, niacin, pantothenic acid, biotin, vitamin B6, and vitamin B12
* These vitamins are precursors of enzymatic cofactors, or coenzymes
Vitamin C
Fat soluble:
* What are the examples?
* Solube in what?
* Vitamin A and D have what?
* Vitamin E is transported by what?
* Vitamin K transported by what?
- Vitamins A, D, E, and K are called the fat-soluble vitamins
- soluble in organic solvents and are absorbed and transported in a manner similar to that of fats
- Vitamin A and D have carrier proteins
- Vitamin E is transported by high density HDL and LDL lipoproteins
- Vitamin K transported by VLDL
What is the vitamin C? Why is it important?
is a cofactor in collagen biosynthesis due to its role in the generation of hydroxyproline residues
* Collagen is a fundamental structural component of connective tissues such as tendons, bone matrix, and cartilage.
Vitamin C (ascorbate) is required in what?
synthesis of certain neurotransmitter receptors and may contribute to host resistance to infection, very effective antioxidant (mops up oxygen free radicals)
Too much vit. C= diarrhea
- Vitamin C deficiency is termed what?
- What are symptoms?
- termed “scurvy”
- Swollen gums, ulceration, easy bruising, and impaired wound healing
Riboflavin, B2:
* Important for what?
* What does deficiency cause?
- Important for red blood cell production and skin integrity
- Deficiency causes sore mouth (angular stomatitis, glossitis) and associated with reduced red blood cell glutathione reductase activity
What are extergonic and endergonic reactions?
- Exergonic reaction: Spontaneous, releases free energy to its surroundings
- Endergonic reaction: not spontaneous, require free energy from its surrounding
What does glycolysis need and produce?
LONG lol
What happens during glycolysis?
Most cellular respiration requires O2 to produce ATP but glycolysis can produce ATP with or without O2. Explain the process
Oxidation Without O2: List the two ways?
- Anaerobic respiration: Use of inorganic molecules (other than O2) as final electron acceptor (CO2)
- Fermentation: Use of organic molecules as final electron acceptor
Fermentation:
* Reduces what?
* What are the two types?
How do you get ethanol from glucose?
Glucose→Pyruvate → Acetaldehyde→Ethanol
What are the products of pyruvate oxidation?
Krebs cycle:
* What is it?
* Where does it occur?
* What are the segments we care about?
One turn around the Kreb cycle gives us?
3 NADH
1 FADH2
1 ATP
2 CO2
After everything: glucose has been oxidized to?
Cellular membranes have 4 components: list them and their functions
Phospholipids composed of?
How do things get through the cell membrane? (two ways)
Utilize proteins in the plasma membrane
◦ Active transport: involves the movement of molecules from lower concentration to higher concentration with the use of energy.
◦ Passive transport: involves the movement of molecules from higher concentration to lower concentration and no amount of energy is required
Explain the difference between carrier proteins vs. channel proteins
Sodium-potassium pump:
* What happens with every ATP spent?
* What does the pump maintain?
* The gradient is essential for what?
Clinical significance of Na+/K+ ATPase (5 of them)
