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BIOCHEM(FINALS)
NOV 22- COENZYMES AND VITAMINS
NOV 24- WATER SOLUBLE VITAMINS
NOV 29- NUCLEIC ACID AND FIRST LONG EXAM
DEC 1- CANCER
DEC 6- PHYTOCHEMICALS
DEC 10- ORAL REPORT
DEC 20- WRITTEN REPORT
TERM PAPER: PARTICULAR ISSUE REGARDING
TO MEDICAL SCIENCE RELATED TO
BIOCHEMISTRY PRINCIPLES
EX: KETOGENIC DIET: IS IT REALLY SAFE OR
NOT?
#1: COENZYMES AND VITAMINS
Coenzymes and vitamins are technically the catalyst of the reaction; without them it is very impossible for different bio metabolic pathway to occur Cofactors are groups that contribute to the reactivity of enzymes beside amino acid residues Cofactors are non-protein chemical compounds that are bound to a protein Helper molecules that assist in biochemical transformations Apoenzymes (inactive form) holoenzyme (active form) Cofactors provide reactive groups not found on amino acid side chains Two types of cofactors: essential ions and coenzymes Essential ions are needed in smaller amount of our body; pure elements and inorganic in nature Essential ions are also known as your minerals: micromineral, macro minerals (K, S, Mg, Ca, Cl, Na), trace minerals (just needed less than 100 mg per day) The least of essential trace elements act as cofactors can include but not limited to Cu that provide a component to your cytochrome oxidase, iron (catalase) etc. Vitamins are natural and organic in nature; it is needed in Coenzymes are organic molecules that act as group-transfer reagents (accept/donor groups): co-substrates or prosthetic groups. Co-substrates are loosely bound to the enzymes which is altered in the reaction but is regenerated afterwards. Prosthetic groups are coenzymes that are tightly bound to the enzyme. Classification of Coenzymes Vitamins are essential Water-soluble vitamins: B-vitamins and Vitamin C characteristics: a. Excess excreted in urine b. Increased risk of deficiency c. Decreased risk of toxicity They also have high affinity in water
Digestion of Vitamins are following the same route of macromolecules but the difference is that there will be no chemical digestion for disco enzymes in the mouth. B-vitamins act as coenzymes to help with energy metabolism/energy production n B vitamins are: B1, B2, and B3 are coenzymes important for energy production The act as a key for the substrates Vitamin B1 (Thiamin) coenzyme form is Thiamin pyrophosphate It is a cofactor for enzymes involved in acetyl-coa formation and TCA cycle, acetylcholine synthesis; nerve function (non-coenzyme) Important in the production of acetyl- CoA, without it, there will be no Krebs cycle to be occurred Pyruvate>Acetyl-CoA, a- ketoglutarate>succinyl CoA, leucine>isovaleryl CoA
Without your pyridoxine, the homocysteine will accumulate in the body that may cause cardiovascular disease It is more important in blood production Methylation of non-essential amino acids. Vitamin B7 (Biotin) it is important in biotinylation of carboxylases to fully activate them The biotin will result the impairment in the process of lipogenesis Without this, your biotin cannot synthesize the fatty acids to be stored, thus it will result to high level of lipid circulating in the body It is important in the production of pyruvate carboxylase Anti-vitamin factor of biotin which is the avidin that can be found in egg whites Biotinidase deficiency characterized of loss of hair Vitamin B9 (Folate) most active form is folic acid (folate monoglutamate) Folate foods>folic acid before they can be absorbed in the small intestine Vitamin B9 must undergo activation before entering hepatic vein It is important in the methylation of non-essential amino acids It is important in cell differentiation, if it insufficient, the RBC cannot and replicate and the DNA cannot divide. Deficiency results to megaloblastic anemia Spina bifida or incomplete closure of spinal cords of infants Vitamin B12 (Cobalamin) it contains the element cobalt; it is also absorbed the way that protein undergone
It requires intrinsic factor and acidic medium Can be found in animal products It is also absorbed in the upper part of small intestine Its deficiency can cause pernicious anemia and megaloblastic anemia This is not found in vegetables To sum up, (B1, B2, & B3) for energy production (B5) beta oxidation of fatty acid (B6, B9, B12) RBC production and methylation of non-essential amino acids (B7) for biotinylation Vitamin C act as receptor binder; act as coenzyme in collagen synthesis Vitamin C are not antioxidant by definition, they just donate their electrons to the free radical. They just neutralize your free radicals It is important for immune system 70-75 mg of vitamin C Excess will be secreted through urine #2 Fat-Soluble Vitamins Vitamin A or the activity of retinol and some of the carotenoids found in plants pigments with provitamin activity Vitamin A, B, E, and K are called retinol which fat soluble in nature Fat-soluble vitamins need a carrier as they cross the brush border of small intestine, it requires to be carried by active transport with the use of energy 1 retinol = 6 micrograms of beta- carotene It is preformed vitamin Carotenoid is Provitamin; found in plant Free-form is synonymous of active form Provitamin A carotenoids are converted to retinol primarily in the enterocytes, but also in liver tissues. Different form of Vitamin A: a. Retinol (alcohol form) b. Retinoic acid (acidic form) c. Retinal (aldehyde form) Is needed for cells which line passages in your body such as inside the GIT and nostrils. Precursor: beta carotene cryptoxanthin; it is the most significant since it is abundant in the food that we are consuming It allows you GIT to have many efficient lines passages Beta-carotene is the most widespread carotenoid in the human diet. It is also use for production of Rhodopsin (purple pigment) is also needed to see at night as it helps certain cells in the eyes adjust to the dark; it is produced by the eye. Helps to keep skin healthy; in epithelial tissue It helps in preventing cancer Vitamin A is not yet an antioxidant vitamin
Excessive thirst Headaches Irritability Weakness Nausea and vomiting Kidney stones Anorexia Death Vitamin E Vitamin E (tocopherols) A group of fat- soluble compounds There are 8 naturally occurring forms: alpha, beta, gamma, and delta classes of tocopherol and tocotrienols Alpha and gamma-tocopherols are of the two major forms It is said to be an anti-oxidant vitamins Vitamin E is the major lipid-soluble component the cell antioxidant defense system: it protects fats vitamin A and other helpful body chemicals from damage. It makes blood more efficient in carrying oxygen around the body Vitamin E can insert itself into cell membranes, where it helps stop free radical chain damage. Food Sources of Vitamin E: PUFA-rich plant oils, Leafy green vegetables, Wheat germ, Almonds, hazel nuts, Seeds, Whole-grain cereals Vitamin E is heavily dependent on vitamin B3, Se, and glutathione. Vitamin E Deficiency Disorders: Breakdown of RBC leading to anemia Nerve degeneration Weakness Difficulty walking and leg cramps Vitamin E Excess Intake: General discomfort Vitamin K: Phylloquinone or K1 (plants) and Menaquinone or K2 (produced by bacteria in the colon) Without vitamin K, you’ll be leading to death This is the sole vitamin that affect your prothrombin time (blood clotting) Food Sources: Liver, Milk, Vegetable oil, Green leafy vegetable, Eggs, meats, Bacterial synthesis in the digestive tract Vitamin K aids in normal blood clotting. Vitamin K is needed for the formation of a protein (OSTEOCLASTIN) that binds calcium in the bone. No known side effects or toxicity symptoms from consuming excess. Vitamin Inhibitors Vitamin A –alcohol, very low-fat diet Vitamin D – mineral oil, alcohol, laxatives, some anticonvulsants, and glucocorticoids Vitamin E – large intakes of vitamin K, laxatives Vitamin K – warfarin, mineral oil, laxatives, large doses of vitamin E Nucleic Acids These are required for the storage and expression of genetic information. There are two chemically distinct types of nucleic acids: deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). DNA,
the repository of genetic information, is present not only in chromosomes in the nucleus of eukaryotic organisms, but also in mitochondria and the chloroplasts of plants. Prokaryotic cells, which lack nuclei, have a single chromosome, but may also contain non chromosomal DNA in the form of plasmids. The genetic information found in DNA is copied and transmitted to daughter cells through DNA replication. The DNA contained in a fertilized egg encodes the information that directs the development of an organism. This development may involve the production of billions of cells. Each cell is specialized, expressing only those functions that are required for it to perform its role in maintaining the organism. DNA must be able to not only replicate precisely each time a cell divides, but also to have the information that it contains be selectively expressed. Because if there is a mutation that may happened during the replication process, a pragmatic condition may occur. TRANSCRIPTION (RNA synthesis) is the first stage in the expression of genetic information. Next, the code contained in the nucleotide sequence of messenger RNA molecules is translated, thus completing gene expression. Types of Nucleic Acids
- Found in the eukaryotic cell: - Deoxyribonucleic acid (DNA) and Ribonucleic acid (RNA). DNA is found in the nucleus with small amounts in mitochondria and chloroplasts - RNA is found throughout the cell. Characteristics of DNA - Present in all cells and virtually restricted to the nucleus - The amount of DNA in somatic cells (body cells) of any given species is constant (like the number of chromosomes) - The DNA content of gametes (sex cells) is half that of somatic cells. - In cases of polyploidy (multiple sets of chromosomes) the DNA content increases by a proportional factor. - The mutagenic effect of UV light peaks at 253.7nm. The peak for the absorption of UV light by DNA - For example, the number of somatic cells in any given species is equal to chromosomes. Half the content somatic cells of gamete contents Structure of DNA - DNA is a polymer of deoxyribonucleoside monophosphates covalently linked by 3' a 5'– phosphodiester bonds. With the exception of a few viruses that contain
- Like DNA, these three types of RNA are unbranched polymeric molecules composed of nucleoside monophosphates joined together by phosphodiester bonds. - However, they differ from DNA in several ways, for example, they are considerably smaller than DNA, contain ribose instead of deoxyribose and uracil instead of thymine, and exist as single strands that are capable of folding into complex structures. Types of RNA - Ribosomal RNA. rRNAs are found in association with several proteins as components of the ribosomes—the complex structures that serve as the sites for protein synthesis. There are three distinct size speciesof rRNA (23S, 16S, and 5S) in prokaryotic cells. tRNAs are the smallest (4S) of the three major types of RNA molecules. There is at least one specific type of tRNA molecule for each of the 20 amino acids commonly found in proteins. - Transfer RNA. tRNAs are the smallest (4S) of the three major types of RNA molecules. There is at least one specific type of tRNA molecule for each of the 20 amino acids commonly found in proteins. - mRNA carries genetic information from the nuclear DNA to the cytosol, where it is used as the template for protein synthesis. Cancer
- Cancer and the cell cycle checkpoints, reqmts to advance oncogenes tumor suppressor genes
- 6 Traits of cancerous cells
- Origins of cancerous cells - Proteins within the cell control the cell cycle
- Signals affecting critical checkpoints determine whether the cell will divide (cyclins, kinases)
- In laboratory cultures, normal cells divide only when attached to a surface = anchorage dependent - Cells continue dividing until they touch one another = density-dependent inhibition - Growth factors are proteins secreted by cells that stimulate other cells to divide - Growth factors bind to specific receptors on the plasma membrane to trigger cell division - Cancer cells have abnormal cell cycles
- divide excessively and form tumors Traits of Cancer cells - 1. Independent of GROW signal from other cells often, oncogenes. Ex. ras - 2. Ignores STOP signal defective damage control, so problems not corrected.
- Chemicals – tar from cigarettes - Virus infection – papilloma virus can be responsible for cervical cancer. - Hereditary predisposition – Some families are more susceptible to getting certain cancers. Remember you can’t inherit cancer its just that you maybe more susceptible to getting it. Benign or malignant? - Benign tumours do not spread from their site of origin, but can crowd out (squash) surrounding cells eg brain tumour, warts. - Malignant tumours can spread from the original site and cause secondary tumours. This is called metastasis. They interfere with neighbouring cells and can block blood vessels, the gut, glands, lungs etc. - Why are secondary tumours so bad? - Both types of tumour can tire the body out as they both need a huge amount of nutrients to sustain the rapid growth and division of the cells. The Development of Cancer
- DNA of a normal cell
- Mutation of DNA
- Genetically altered cell
- Spread and second mutation
- Third mutation
- Fourth mutation
- Breaking through the membrane
- Angiogenesis
- Invasion and dispersal
- Tumour cells travel – metastasis
- Metastasis PHYTOCHEMICALS This are the substances that can be found in plants which has beneficial effect to the human body but it is not non-nutrient component of the body. Functional Groups: oatmeal and yogurt Nutraceutical: Lutin and Liver-aid Pharmafood: nutrional/oral supplements, pediasure, milk Phytochemical: fruits and vegetables (deeply colored) Chemoprevention Designer food: pineapple juice Also known as Phytonutrients For example, some phytonutrients protect the plant from UV radiation while others protect it from insect attack Its also important to understand that each of these foods contain many different phytochemicals that can care if different oxidation reactions in our cells
Function of Phytochemicals Antioxidant - Most phytochemicals have antioxidant activity and protect our cells against oxidative damage and reduce the risk of developing certain types of cancer. Phytochemicals with antioxidant activity: allyl sulfides (onions, leeks, garlic), carotenoids (fruits, carrots), flavonoids (fruits, vegetables), polyphenols (tea, grapes). Hormonal action - Isoflavones, found in soy, imitate human estrogens and help to reduce menopausal symptoms and osteoporosis. Stimulation of enzymes - Indoles, which are found in cabbages, stimulate enzymes that make the estrogen less effective and could reduce the risk for breast cancer. Other phytochemicals, which interfere with enzymes, are protease inhibitors (soy and beans), terpenes (citrus fruits and cherries). Interference with DNA replication - Saponins found in beans interfere with the replication of cell DNA, thereby preventing the multiplication of cancer cells. Capsaicin, found in hot peppers, protects DNA from carcinogens. Anti-bacterial effect - The phytochemical allicin from garlic has anti-bacterial properties. Physical action - Some phytochemicals bind physically to cell walls thereby preventing the adhesion of pathogens to human cell walls. Proanthocyanins are responsible for the anti-adhesion properties of cranberry. Consumption of cranberries will reduce the risk of urinary tract infections and will improve dental health. Do we need supplements?
- Foods containing phytochemicals are already part of our daily diet. - In fact, most foods contain phytochemicals except for some refined foods such as sugar or alcohol. - Some foods, such as whole grains, vegetables, beans, fruits and herbs, contain many phytochemicals. - The easiest way to get more phytochemicals is to eat more fruit (blueberries, cranberries, cherries, apple...) and vegetables (cauliflower, cabbage, carrots, broccoli...). - It is recommended take daily at least 5 to 9 servings of fruits or vegetable. - Fruits and vegetables are also rich in minerals, vitamins and fiber and low in saturated fat.
Tri-terpenoids Monoterpenes Carotenoids Xanthophylls Phenolic acids
Phenols
Lycopene Benefits: ↓ Cancer↑ Memory, Heart Carotenoids Benefits: ↓ Cancer, Vision, Immune system Lutein Benefits: Vision, Bone strength, ↓Cancer Anthocyanins Benefits: ↓ Cancer, ↑ Memory, ↓ Aging effects Most Studied Phytochemicals Allium foods. Garlic, onions, shallots, leeks, and chives belong to the Allium family, which contain allyl sulfides. Besides making your eyes water, allyl sulfides have been shown to inhibit tumors in animals. And studies have shown that people who eat a lot of garlic and onions reduce their risk of stomach and colon cancer. The more pungent the Allium food, the higher its content of allyl sulfides. The Brassica family. Broccoli, cabbage, and many others belong to the Brassica family of vegetables and contain the important phytochemicals sulforaphane, indoles, and isothiocyanates. Sulforaphane has been shown
to prevent breast cancer in lab animals. Indoles work against the dangerously high levels of estrogen associated with breast cancer, potentially reducing the risk. Isothiocyanates have been associated with prevention of stomach and lung cancers. Carotene-containing foods. Beta-carotene, probably the best known of the phytochemicals and responsible for the color of carrots, is a potent antioxidant. (Antioxidants thwart oxidation, a normal metabolic process that, when left unchecked, can leave the body vulnerable to accelerated aging, cancer, cardiovascular disease, and degenerative diseases like arthritis.) Other carotenes, especially alpha-carotene, have recently been associated with reduced lung cancer risk. Tomatoes. Tomatoes contain as many as 10,000 phytochemicals. One of the most well- studied is lycopene, an antioxidant that has been shown to help prevent heart disease and cancer. Regular tomato consumption has been associated with a reduction in the risk of prostate and stomach cancers. Soy. Phytoestrogens are phytochemicals found predominantly in soy foods like tofu, tempeh, and miso. During a woman's childbearing years, phytoestrogens help prevent breast cancer by inhibiting the action of naturally occurring estrogens. Because they also regulate other hormones, phytoestrogens may help prevent cancer of the prostate, another hormone-dependent cancer. Genistein, another phytochemical in soy, has been shown to reduce the size of LDL- cholesterol particles (harmful cholesterol) and lower the build-up of coronary artery plaque in primates. By consuming about half of your protein in the form of soy (31 to 47 grams per day), you may be able to reduce your risk of heart disease and cancer. Other sources. Other plant foods--beverages, condiments, seasonings, and vegetable oils-- contain substantial amounts of phytochemicals. Monoterpenes, for example, are associated with a reduction in the risks for cancer of the breast, skin, liver, lung, stomach, and pancreas. The polyphenols found in green tea have antioxidant properties, and research indicates that they may be protective factors against cancers of the skin, lung, and stomach. Vegetable oils contain alpha-linolenic acid and are the greatest source of vitamin E. These nutrients have a dual role as antioxidant phytochemicals. For people who exercise, antioxidants are important because they help guard against the muscle-cell membrane damage and inflammation associated with hard exercise. Compounds in alpha-linolenic acid may also help prevent heart disease. Capsaicin - This chili pepper-derived spice packs the wallop in your hot tamale, but it is also a digestive aid, a topical painkiller, and a potential cancer-fighting compound. Catechin Hydrate - Never mind the fortunetellers and soothsayers. Thanks to their cancer-fighting properties, tea leaves could give everybody a great future. Coumarin - Rats could live longer without this blood thinning agent that doubles as a rat poison, but warfarin (a coumarin derivative) is the most commonly used oral anticoagulant medication. Coumesterol - An isoflavone coumarin derivative found in soy products, this phytoestrogen appears promising as a naturally-occurring cancer preventative. Genistein - Found in soy products, genistein is an isoflavone derivative that is proving to be a strong inhibitor of cancer and may be useful in the creation of new anti-cancer drugs.
