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This is soooooooo weird im not doing biochem anymore im doing Pharmacy but my awesome pain in the butt blog is still here and when i came back there are so many memories of saying i hate this shit! wow totally amazing good tmes i miss my friends and uwi and kfc and amelia singh ❤

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Lipids are found in all living molecules and play an essential role in he maintenance of life. Unlike carbohydrates and proteins, lipids are highly polymorphic and structurally difficult to define. As a result they are classified according to their major feature as water insoluble (or mostly insoluble) organic compounds found in biological systems. Lipids can be either amphipathic (having polar and nonpolar qualities) or hydrophobic (nonpolar).
 
Even though lipid structures can be relatively complex, there are a few common structural themes. The simplest lipids are the fatty acids with the general formula R-COOH, where R is the hydrocarbon tail. Fatty acids can also be constituents of more complex lipds such as triacylglcerols, glycerophospholipids, and sphingolipids, as well s waxes and eicosanoids. On the other hand there are structurally distinct lipids like steroids and lipid vitamins which are derived from a five carbon molecule called isoprene. Below is a figure outlining the most important types of lipids and their relations to one another.

 

 

1.           

Glycolytic pathway regulation involves

 

A.            allosteric stimulation by ADP

B.            allosteric inhibition by ATP

C.            feedback, or product, inhibition by ATP

D.            all of the above

 

2.           

During catabolism, only about 40% of the energy available from oxidizing glucose is used to synthesize ATP. Remaining 60%

 

A.            is lost as heat

B.            is used to reduce NADP

C.            remains in the products of metabolism

D.            is stored as fat.

 

3.           

Why does the glycolytic pathway continue in the direction of glucose catabolism?

 

A.            There are essentially three irreversible reactions that act as the driving force for the pathway

B.            High levels of ATP keep the pathway going in a forward direction

C.            The enzymes of glycolysis only function in one direction

D.            Glycolysis occurs in either direction

 

4.           

The released energy obtained by oxidation of glucose is stored as

 

A.            a concentration gradient across a membrane

B.            ADP

C.            ATP

D.            NAD+

5.           

A kinase is an enzyme that

 

A.            removes phosphate groups of substrates

B.            uses ATP to add a phosphate group to the substrate

C.            uses NADH to change the oxidation state of the substrate

D.            removes water from a double bond

 

 

6.           

For every one molecule of sugar glucose which is oxidized __________ molecule of pyruvic acid are produced.

 

A.            1              B.            2

C.            3              D.            4

 

7.           

In the glycogen synthase reaction, the precursor to glycogen is

 

A.            glucose-6-P        B.            UTP-glucose

C.            UDP-glucose      D.            glucose-1-P

 

8.           

The active form of glycogen phosphorylase is phosphorylated, while the dephosphorylation of which active form occurs?

 

A.            Glycogen synthase

B.            Glycogen semisynthase

C.            Glycogen hydrolase

D.            Glycogen dehydrogenase

 

9.           

The amount of energy received from one ATP is

 

A.            76 kcal

B.            7.3 kcal

C.            760 kcal

D.            1000 kcal

 

10.         

The enzymes of glycolysis in a eukaryotic cell are located in the

 

A.            intermembrane space

B.            plasma membrane

C.            cytosol

D.            mitochondrial matrix

ENZYMES TO TREAT CANCER

 

The idea of suicide gene therapy was proposed by pharmacy associate professor Marek Malecki who has a M.D and a P.H.D in pharmaceutical biotechnology by a method called apoptosis; the orderly programmed death of cells.

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This is the process by which enzymes bring about the death of enzymes. Cancer can be detected in its early stages if the genetic markers that trigger these cells can be found.  Malecki’s idea is to regulate the signals for the transduction pathways that trigger the death of cells by use of enzymes.

When our cells are healthy, working and respiring they produce ‘free radicals’ these are the byproducts of cell respiration, this can therefore act as a genetic marker to trigger the death of cells. And unlike normal everyday treatment such as chemotherapy and which cause significant damage to the body’s normal healthy cells, suicide gene therapy does not harm those cells but rather only affects the cancer cells.

 Cells, normal and cancer produce free radicals with increases metabolism. But cancer cells divide more rapidly and hence respire more than normal cells producing more free radicals. This is where the use of enzymes comes in; there are 4 ‘anti-oxidative enzymes’ that help create free radical processing pathways which convert the free radicals into harmless molecules example water. The idea is to introduce a substance (transgenes) that can block these pathways and allow the buildup of these free radicals in the cancer cells which would then trigger expression of suicide genes and ultimately kill the cell.

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Glycolysis (from glycose, an older term for glucose + -lysis degradation) is the metabolic pathway that converts glucose C6H12O6, into pyruvate, CH3COCOO− + H+. The free energy released in this process is used to form the high-energy compounds ATP (adenosine triphosphate) and NADH (reduced nicotinamide adenine dinucleotide).[2]
Glycolysis is a determined sequence of ten reactions involving ten intermediate compounds (one of the steps involves two intermediates). The intermediates provide entry points to glycolysis. For example, most monosaccharides, such as fructose, glucose, and galactose, can be converted to one of these intermediates. The intermediates may also be directly useful. For example, the intermediate dihydroxyacetone phosphate (DHAP) is a source of the glycerol that combines with fatty acids to form fat.

Enzyme inhibitors are molecules that interact in some way with the enzyme to prevent it from working in the normal manner. There are a variety of types of inhibitors including: nonspecific, irreversible, reversible – competitive and noncompetitive. Poisons and drugs are examples of enzyme inhibitors.

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Competitive Inhibitors:

A competitive inhibitor is any compound which closely resembles the chemical structure and molecular geometry of the substrate. The inhibitor competes for the same active site as the substrate molecule. The inhibitor may interact with the enzyme at the active site, but no reaction takes place. The inhibitor is “stuck” on the enzyme and prevents any substrate molecules from reacting with the enzyme. However, a competitive inhibition is usually reversible if sufficient substrate molecules are available to ultimately displace the inhibitor. Therefore, the amount of enzyme inhibition depends upon the inhibitor concentration, substrate concentration, and the relative affinities of the inhibitor and substrate for the active site.

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Non competitive Inhibitors:

A noncompetitive inhibitor is a substance that interacts with the enyzme, but usually not at the active site.  The noncompetitive inhibitor reacts either remote from or very close to the active site.  The net effect of a non competitive inhibitor is to change the shape of the enzyme and thus the active site, so that the substrate can no longer interact with the enzyme to give a reaction. Non competitive inhibitors are usually reversible, but are not influenced by concentrations of the substrate as is the case for a reversible competive inhibitor.  See the graphic on the left.

Irreversible Inhibitors form strong covalent bonds with an enzyme.  These inhibitors may act at, near, or remote from the active site.  Consequently, they may not be displaced by the addition of excess substrate.  In any case, the basic structure of the enzyme is modified to the degree that it ceases to work. 

Since many enzymes contain sulfhydral (-SH), alcohol, or acid groups as part of their active sites, any chemical which can react with them acts as an irreversible inhibitor. Heavy metals such as Ag+, Hg2+, Pb2+ have strong affinities for -SH groups.

Nerve gases such as diisopropylfluorophosphate (DFP) inhibit the active site of acetylcholine esterase by reacting with the hydroxyl group of serine to make an ester.

Oxalic and citric acid inhibit blood clotting by forming complexes with calcium ions necessary for the enzyme metal ion activator.

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