General Biochemistry

·         ACUTE-PHASE PROTEINS: Proteins released by the liver when the body is under stress.

ü  alpha1-Antitrypsin: Protease inhibitor. When there is tissue damage, the dead tissue releases proteases, so the anti-proteases help to prevent further damage.

ü  alpha2-Macroglobulin: Indirect anti-protease that fixes proteases and allows macrophages to engulf them.

ü  C-Reactive Protein (CRP): Opsonin, help to fix antibodies to antigen to facilitate phagocytosis.

ü  Ceruloplasmin: Copper-carrying protein, and anti-oxidant.

ü  Complement Proteins: Inflammatory mediators.

ü  Ferritin: Iron protein-carrier.

ü  Fibrinogen: Clotting factor.

ü  Haptoglobin: Binds to hemoglobin in blood.

ü  Serum Amyloid A Protein: Apolipoprotein.

·         PROTEIN ELECTROPHORESIS: alpha1, alpha2, beta, and gamma zones all have distinct proteins.

alpha1 Zone: Closest to the anode (right): Albumin, Pre-Albumin: Fetal albumin is called pre-albumin. It consists of two proteins. (AFP & Transthyretin)

alpha2 Zone: alpha2-Macroglobulin, Haptoglobin, Ceruloplasmin, GC Globulin

beta Zone: LDL Lipoprotein, Transferrin, C3 Complement Factor, beta2-Microglobulin, Hemopexin

gamma Zone: Closest to cathode (left) : Fibrinogen, Lysozyme, Ig, CRP

·         LDH-Flip: LDH-5 is normally highest, but in cases of MI LDH-1 may be higher. This is called an LDH-flip and is suggestive of MI.

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·         Proteins are the most important intracellular buffer.

Bicarbonate is the most important extracellular buffer.

·         In order to absorb molecules they need to remain neutral = bioavailable.  Follow these rules to keep molecules neutral.

1. To absorb more acid need to place in a stronger acid
1. Acid + Strong Acid = Behaves as a BASE
2. To absorb more base place in a stronger base
1. Base + Strong Base = Behaves as a ACID
3. Understand that the body makes 20x more HCO₃^- than acid
1. Because we ingest primarily acidic substances

·         If ingest acid à need to keep it charged so it will not be absorbed à give base (NaHCO₃)

o   Recall Activated Charcoal in the ER

If ingest base à keep charged by giving acid (coke, juice) à will absorb less base.

·         Water molecules have a dipole nature and dissolve salts because of attractions between the water dipoles and the ions that exceed the force of attraction between the oppositely charged ions of the salt. In addition, the latter force is weakened by the high dielectric constant of water. Nonionic but polar compounds are dissolved in water because of hydrogen bonding between water molecules and groups such as alcohols, aldehydes, and ketones.

·         Cathode – is where cations GO

Anode – is where anions GO

·         Ninhydrin Reaction: Separate out proline

Proline will stain yellow

All others will stain purple.

·         Edmund’s Degradation: Degradation that needs Propylisothiocyanate (PITC)

Will react with one amino acid at a time

From the L amino terminal

Used in spectrophotometry

Good for only 100 amino acids accuracy.

·         All Restriction Peptidases CUT TO THE RIGHT.

EXCEPTION: Carboxy peptidase - cuts to the LEFT of any amino acid on carboxy terminal.

·         ALA Synthase & Ferrochelatese Both are inhibited by LEAD POISONING

·                     In Methemaglobanemia  Low O₂ saturation BUT pO₂ will be normal

Treatment:

ü          Methylene Blue – “Give them something blue to turn them pink”

ü          Anyl Nitrite- will convert Hg to Fe³⁺ not allowing CN to act.

ü          Sodium Thiosulfate will bind CN and recant thiocyanate

ü          Blood transfusion

·                     Collagen in the ONLY protein to get modified in ER. All other proteins get modified in the Golgi.

·         DESMOSINE in Elastin gives it ELASTIC Property. Desmosine is a major cross link in elastin and is unique to it. It is formed by three lysine derived aldehydes and one lysine residue.

·         Disulfide Bond can be disrupted by Water, Alcohol.

·         Coomb’s Test

o   This test tells if an anti-body is killing the RBC → indication of Autoimmune attack against RBC

§  Direct Test → Antibodies are ON the RBC surface causing the hemolysis

§  Indirect Test → There are antibodies in the serum causing the hemolysis

·         Non-collagen collagen : substances that are not collagen but work similarly. e.g. C1 q complement component , SP A , SP D the pulmonary surfactanty proteins.

·         Mucin in GIT and genitourinary tract is a glycoprotein.

·         Saturated fatty acids have straighter tails , but the unsaturated fatty acids have kinked tails. This needs more space and thus creates in the membrane an ability to be a fluid structure.

·         Centrifugation of a cellular homogenate at a force of 100,000 × g will pellet all cellular organelles and membranes.

Only soluble cellular molecules found in the cytosol will remain in the supernatant. Thus, the enzymes of glycolysis and most of those of gluconeogenesis, fatty acid synthesis, and the pentose phosphate pathway will be in the supernatant. Glucose-6-phosphate dehydrogenase, which results in the formation of 6-phosphogluconolactone from glucose-6-phosphate, is the committed step in the pentose phosphate pathway.

In the pellet will be the enzymes within mitochondria, including those of the citric acid cycle (aconitase), fatty acid beta oxidation (acyl CoA hydratase), and ketogenesis (hydroxybutyrate dehydrogenase). Enzymes of glycogen degradation and synthesis (glycogen synthetase) will also be in the pellet associated with glycogen particles.

·         The primary control hormones of metabolism are insulin and glucagon. Epinephrine has effects similar to those of glucagon, except that glucagon has a greater effect on the liver while epinephrine has a greater effect on muscle.

·         A coenzyme usually binds loosely and can be separated from the enzyme. When a coenzyme binds tightly to an enzyme, it is spoken of as a prosthetic group of the enzyme. Coenzymes can be viewed as a second substrate for the enzyme, often undergoing chemical changes that counterbalance those of the substrate.

·         Cofactors are distinguished from coenzymes because cofactors do not function in group transfer and do not undergo chemical reactions (other than changes in valence due to oxidation/reduction). Cofactors are usually metallic ions rather than organic molecules, including cobalt, copper, iron, molybdenum, selenium, and zinc. Examples include copper in cytochrome oxidase, iron in all the cytochromes, magnesium for all enzymes utilizing ATP, zinc in lactate dehydrogenase ,Selenium in Glutathione Peroxidase, Manganese in SOD & Glycosyl Transferase, Molybdenum in Xanthine Oxidase. Chromium enhances Insulin Activity. Zinc deficiency causes a clinical syndrome called acrodermatitis enterohepatica with growth failure, diarrhea, loss of hair, eyelashes, and eyebrows, and skin rashes with redness and scaling on the extremities (acrodermatitis). Arsenic, lead, and antimony cause disease when present in excess while vanadium (along with silicon, nickel, and tin) is known to be essential from experimental nutritiion studies but its role is not defined. Fluoride (preventing dental caries) and lithium (a therapy for depression) have effects on humans but are not known to be essential nutrients.