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58 Cards in this Set
- Front
- Back
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____________ convert all monosaccharides into glucose, which becomes the final common pathway for transport of all carbohydrates to tissue cells.
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Liver hepatocytes
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GLYCOLYSIS
-results in the formation of _________ -yields a net gain of _ ATP molecules -occurs in the ______ of cells -most of the reactions require enzymes -completely ______ (aerobic or anaerobic) when complete - decision time for the cell 1) anaerobic conversion to ______ 2) aerobic conversion to _____ |
pyruvic acid, 2, cytosol, anaerobic, lactic acid, acetyle-CoA
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The first step of glycolysis is the phosphorylation of glucose by either __________ in liver hepatocytes or _______ in most other cells.
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glucokinase or hexokinase
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The phosphorylation of glucose is irreversible except in: (3 places)
-These cells possess glucose-6-phosphatase which reverses the phosphorylation of glucose. In cells without this enzyme, phosphorylation captures glucose. |
liver hepatocytes, some kidney cells, some intestinal cells
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KREBS CYCLE
-breaks down _______ -leads to the creation of NADH and FADH2 – co-factors used by the ____________for -ATP production occurs in the ________ -produces _________ as wastes -completely _______ -with the electron transport system, it leads to the creation of more ATP (__ molecules) compared to glycolysis |
acetyl CoA, electron transport system, mitochondria, H2O and CO2, aerobic, 34
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Series of reactions that convert glucose into glycogen
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glycogenesis
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Glycogenesis requires the enzyme __________.
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glycogen synthase
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Series of reactions that splits glycogen into G6P via glycogen phosphorylase
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glycogenolysis
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G6P can be converted into _____ via _____________ in liver hepatocytes, some kidney cells & some intestinal cells – this glucose can enter the bloodstream
G6P is NOT converted into glucose within skeletal muscle cells – Why ? |
glucose, glucose-6-phosphatase, skeletal muscles don't have glucose-6-phosphatase enzyme
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In kidney cells and intestinal cells, glucose-6-phosphatase is normally ________ – hence, G6P often accumulates inside these cells (like skeletal muscle cells) and enters the glycolysis pathway to make ATP
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inactivated
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This disease results from a deficiency of glycogen phosphorylase inside skeletal muscle cells. As a result, glycogen accumulates in skeletal muscle cells. Patients develop skeletal muscle pain and stiffness on exertion, and they have a greatly reduced exercise tolerance. They cannot break down their muscle glycogen to provide energy for contraction, and any glucose reaching their skeletal muscles from the bloodstream is sufficient only for mild exercise. Hepatocyte glycogen phosphorylase is normal.
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McArdle's Disease
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The _________ in many ways is the body’s “glucostat” – it uptakes glucose when the blood level is above normal & releases glucose when the blood level is abnormally low.
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liver
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Glucose uptake & glucose release by the liver are strictly regulated by the actions of many __________.
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hormones
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When the liver hepatocytes & skeletal muscle cells approach saturation with glycogen, the additional glucose is converted into fat by __________ & _______ and is stored as fat in the adipocytes.
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hepatocytes, adipocytes
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In physiology, ________________ refers to the point at which increases in concentration do not result in an increase in movement of a substance across a membrane.
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transport maximum
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glomerulus, Bowman’s capsule and proximal convoluted tubule (PCT) are part of what?
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kidney nephrons
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When the transport maximum (Tm) is exceeded by cells lining the PCT, appreciable amounts of filtered glucose appear in the urine, producing _________.
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glycosuria
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Amino acid degradation occurs almost entirely in the ______, and it begins with a process known as ________, which is the removal of amine (-NH2) groups from the amino acids.
____________ reactions require a set of enzymes known as _______: |
liver, deamination, deamination, aminotransferases
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High blood levels of ___ (SGPT) and ___ (SGOT) can be indicative of liver disease.
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ALT, AST
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Deamination reactions require a set of enzymes known as aminotransferases:
-SGOT (serum glutamate-oxaloacetate transaminase) also called _____________ -SGPT (serum glutamate-pyruvate transaminase) also called ________________ |
aspartate transaminase - AST
alanine transaminase - ALT |
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LFT (liver function test)usually consists of seven tests that are run at the same time on a blood sample. These include:
-Alanine aminotransferase (ALT) – an enzyme mainly found in the liver; the best test for detecting _______ -Alkaline phosphatase (ALP) – an enzyme related to the bile ducts; often increased when they are blocked or inflamed; when this occurs, the ALP can overflow like a backed up sewer and seep out of the liver and into the bloodstream -Aspartate aminotransferase (AST) – an enzyme found in the liver and a few other places, particularly the ____ and other muscles in the body |
hepatitis, heart
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_______ bilirubin measures all the bilirubin in the blood; _______ bilirubin measures a form that is conjugated.
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total, direct
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The main protein made by the liver.
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albumin
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The seven tests in an LFT:
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ALT, ALP, AST, bilirubin (total and direct), albumin, total protein
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A build-up of urea in the blood can lead to a state of ________ or ______, in which high levels of urea become toxic to a variety of tissues.
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azotemia or uremia
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Ultimately, the amine groups cleaved from the amino acids are converted into _____ (NH3) or ______ ions (NH4+), which are then converted into _____. Essentially all urea formed in the human bodyl is synthesized in the _____. In serious _____ disease, ammonia can often accumulate in the blood and lead to a state called __________. After its formation, ______ diffuses from liver hepatocytes into the body fluids and is excreted by the kidneys.
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ammonia, ammonia, urea, liver, liver, ammonia, hepatic coma, urea
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Elevated BUN can occur with:
Normal BUN has a range of 5-26 mg/dL in the adult |
-impaired renal function
-increased protein intake or catabolism -GI bleeding (due to intestinal flora creating nitrogenous waste) -dehydration |
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Amino acids can be used for energy in 3 ways:
1) Conversion to ______, which are then fed into the Krebs cycle to make ATP 2) ___________ – the process of amino acids being converted into glucose; occurs exclusively in the ______ 3) Conversion to _______ then to fatty acids – the fatty acids can be used to create triglycerides (stored energy) or be directly fed into the Krebs cycle (immediate energy); the feeding of fatty acids into the Krebs cycle to make ATP is called ________. |
keto acids, gluconeogenesis, liver, keto acids, beta oxidation
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Cushing’s syndrome (too much ______)
Type I diabetes mellitus Starvation Burns Results in what kind of nitrogen balance? |
cortisol, negative,
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Growth (e.g. – puberty)
Pregnancy Use of anabolic steroids What would the nitrogen balance be? |
positive
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Many amino acids can be converted into ______, which can then be used to create _______, which can then be used to form ___________. Therefore, when there is more protein in the diet than tissues can use, a large share of the excess is stored as fat.
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acetyl-CoA, fatty acids, triglycerides
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Adults normally excrete small amounts of AAs – 95% of AAs are reabsorbed in the PCT
Aminoacidurias can occur for 2 reasons: 1) Enzyme derangement leading to _______ accumulation in the blood and then exceeding of the renal threshold 2) Defective __________ in the PCT |
amino acid, reabsorption
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An example of an excessive amino acid level in the blood producing aminoaciduria is ______________. It is characterized by a deficiency of ___________ hydroxylase, the enzyme needed for conversion of ___________ to tyrosine. As a result, toxic levels of ____________ accumulate in the blood. Newborns are routinely screened for abnormal levels of serum _____________.
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phenylketonuria (PKU), phenylalanine, phenylalanine, phenylalanine, phenylalanine
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Normally the __________ in the kidneys prevent the passage of protein from the blood to the glomerular filtrate. Thus, the persistent presence of protein in the urine is the single most __________ indication of renal disease (e.g. – glomerulonephritis, polycystic kidney disease, etc.). Also called _______.
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glomeruli, important, proteinurea
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Three major types (make up approx. 98-99% of all plasma proteins):
_______ ________ ________ Several minor types: -Protein hormones (e.g. – insulin, ADH, PTH, etc.) -Transferrin -Angiotensinogen -Ceruloplasmin -Haptoglobin |
albumin, globulin, fibrinogen
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Essentially all the albumin & fibrinogen, as well as 50-80% of the globulin is formed in the ______. The remainder of the globulins are formed almost entirely in the ___________. They are mainly the gamma-globulins that constitute the antibodies used in the immune system.
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liver, lymphoid tissue
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The functions of the major classes of plasma proteins include:
-exertion of _______ pressure across capillary membranes, which in turn, prevents plasma loss (albumin) -supplying approx. 15% of the ________ capacity of the blood (albumin) -___________ of thyroid, adrenocortical, gonadal and other hormones (albumin & globulin) -acting as ________ for metals, ions, fatty acids, amino acids, bilirubin, enzymes and drugs (albumin & globulin) -participating in __________ (fibrinogen) -participating in ________ responses (gamma-globulin) |
oncotic, buffering, transport, carriers, blood clotting, immune
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**Decreased plasma protein concentration ________ plasma oncotic (osmotic) pressure, which often leads to the development of ______.**
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decreases, edema
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Certain disease states can cause a decreased concentration of plasma proteins (hypoproteinemia; hypoalbuminemia):
-_______ disease can decrease the production of plasma proteins proteinuria associated with renal disease -prolonged ___________ -loss of protein across _____ of the skin |
liver, starvation, burns
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When the tissues become depleted of proteins, the _________ can act as a source for rapid replacement of the tissue proteins. Via _________, cells can intake whole plasma proteins. Once inside, they are split into amino acids that are transported back into the blood and used throughout the body to build cellular proteins wherever needed. In this way, the __________ function as a labile protein storage medium and represent a rapidly available source of amino acids wherever in the body a particular tissue requires them.
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plasma proteins, pinocytosis, plasma proteins
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The 3 major types of lipids:
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triglycerides (sat and unsaturated), cholesterol, phospholipids
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Fats have a _________ backbone and ___________.
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glycerol, fatty acids
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Lipids circulate in the bloodstream in three primary forms:
In all three scenarios, the lipid material is bound to protein or covered in a protein coat in order to make it more water soluble. It is also important to note that small amounts of triglycerides and cholesterol can indeed circulate unbound to protein. |
-Free fatty acids (FFA) bound to albumin
-Chylomicrons -Lipoproteins |
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Dietary lipids are digested & then absorbed within the _______ into the ___________ (lacteals). As they are absorbed, they are packaged by the enterocytes into __________.
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small intestine, lymphatic circulation, chylomicrons
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Once the chylomicrons enter the lymphatic circulation, they are transported upward through the ________ and emptied into the venous circulation at the juncture of the _____________ and _____________ veins.
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thoracic duct, jugular, subclavian
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___________ are removed from the blood as they pass through the capillaries of adipose tissue and the liver. Both contain large quantities of ________. This enzyme is especially active in the capillary endothelium, where it hydrolyzes the TGs of chylomicrons into fatty acids & glycerol, which diffuse into adipocytes (storage) & hepatocytes (re-packaged into lipoproteins & exported to blood).
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chylomicrons, lipoprotein lipase
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What enzyme removes lipids from chylomicrons?
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lipoprotein lipase
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What happens to chylomicron remnants?
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Liver disposes of them
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The liver excretes cholesterol as ___________.
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Bile salts
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Chylomicrons are synthesized by the enterocytes of the ________, while VLDL, IDL, LDL & HDL are synthesized by ________________.
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small intestine, liver hepatocytes
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What is the difference between fatty acids and free fatty acids?
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Whether or not they are bound to albumin
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FFAs are broken down into 2-carbon segments, which then attach to coenzyme A to form _______. This is called __________ and occurs in the __________.
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acetyl CoA, beta oxidation, mitochondria
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________________ (HSL) is an enzyme that catalyzes the breakdown of stored triglycerides into glycerol and fatty acids. The released fatty acids bind to _______ to become FFAs, which are then taken up by various cells.
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Hormone sensitive lipase, albumin
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Acetyl-CoA can sometimes be formed too quickly in mass quantities as the bloodstream is flooded with _____.
Such a situation can happen in Type I diabetes mellitus with liver hepatocytes. If there are too many acetyl-CoA molecules than can be fed into the Krebs cycle, they will be converted into ______________. |
FFAs, ketone bodies or ketones
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What does ketoacidosis do to blood pH?
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lowers
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Ketoacidosis should not be confused with ketosis, which is one of the body's normal processes for the metabolism ___________.
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body fat
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A type of metabolic acidosis which is caused by high concentrations of ketone bodies, formed by the deamination of amino acids, and the breakdown of fatty acids. This is most common in untreated type 1 diabetes mellitus, when the liver breaks down fat and proteins in response to a perceived need for respiratory substrate. It can also occur with people undergoing hunger strikes, fasting over 3 days, or people starving to death as the body is forced to break down fat for sustenance due to their lack of outside nutrition.
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ketoacidosis
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An important enzyme required for endogenous cholesterol synthesis is _____________. The “statin” drugs (e.g. – Lovastatin, Mevacor) inhibit endogenous cholesterol synthesis by inhibiting this enzyme.
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HMG-CoA reductase
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