Chapter 12 Nutrients & metabolism

describe the general structure of enzymes

>All protein are composed of amino acids, 22 different types of amino acids, all composed of three important FUNCTIONAL GROUPS: 1. a basic anime group (--NH2), 2. organic group (--COOH2), & 3. an R group > Differences in the R group make each amino acid unique, but the acidic & basic groups are identical among all amino groups > proteins are created when amino acids link together [like pearls on a string]. The acid group from one amino acid links to the basic group on the next, forming a PEPTIDE BOND. DIPEPTIDE molecule - two amino acids link together, TRIPEPTIDE- three amino acids together, & more than ten amino acids link to form POLYPEPTIDE > Proteins are huge molecules- MACROMOLECULES. composed of 100 to 10,000 amino acids, any polypeptide with 50 or more amino acids is considered a protein. When a protein becomes particularly large, it coils to increase its molecular stability. > Type & order of amino acids determine structure & function of the protein. Each of the 22 amino acids is analogous to a letter in an alphabet, letters used & order in which letters are arranged determine a particular action or meaning. Ex., if chain reads "Have a nice day", & only one amino acid is altered in the chain to read "Have a mice day", the meaning becomes very different & possibly nonsensical.

water-soluble vitamins & list their dietary sources & functions

>B complex vitamins, VITAMIN B1 -(thiamine) meat, fish, eggs, leafy green vegetables, legumes, liver *Limited amount stored. Required for the transformation of pyruvic acid to acetyl CoA in carbohydrate metabolism. Needed in the synthesis of some neurotransmitters (acetylcholine). Rapidly destroyed by heat >VITAMIN B2 (riboflavin) - milk, meat (fish, poultry, & red meats), liver, eggs, grains, legumes. *Found in the body as flavin mononucleotides (FAD and FMN), which serve as hydrogen acceptors. Also needed for oxidation of amino acids > VITAMIN B3 (niacin or nicotinamide) - milk, meat (fish, poultry, & red meats), liver, eggs, grains, potatoes, peanuts, leafy green vegetables, yeast, liver. *The amino acid tryptophan, which is found in many food groups, is easily converted to niacin. Niacin is part of nicotinamide adenine dinucleotide (NAD+) which is important in glycolysis, & in catabolism of fats. >VITAMIN B5 (Pantothenic acid) - Found in large quantities in internal organs such as brain, kidney, liver, adrenal, & heart. Also found in grains, legumes, eggs, & yeast. Name refers to the Greek word PANTHOS, meaning everywhere, & referring to the diverse dietary sources. *Stable when heated. Is a major component of coenzyme A. Important in the oxidation of fatty acids & in the synthesis of steroids & hemoglobin. >VITAMIN B9 (FOLACIN OR FOLIC ACID) - lean beef, eggs, veal, whole grains, liver, orange juice, deep green vegetables, yeast. A crystalline vitamin that is bright in color. *Essential for the formation of RBCs. Is one of many coenzymes that are part of methionine, choline, & DNA synthesis >VITAMIN B12 (cyanocobalamin) - Found in liver, meat (poultry, fish, & red meat), dairy (not eggs), & butter. Not found in plants. INTRINSIC FACTOR is required for absorption in the intestine. *Stored in the liver in quantities that meet bodily needs for 3 to 5 years. Essential for the synthesis of methionine & choline. Is a coenzyme in all cells in the body, particularly in the nervous system, bone marrow, & gastrointestinal tract. >BIOTIN (VITAMIN H) - Liver, eggs, nuts, & legumes. In some species, it is generated by enteric bacteria in the gut.* Essential for the reactions in the Krebs cycle. Functions as a coenzyme in a # of reactions, including: carboxylation, decarboxylation, deamination, & anabolism of purines & nonessential amino acids >VITAMIN C- Found in fruits & vegetables, especially large quantities in citrus fruits, leafy green vegetables, tomatoes, cantaloupe, & strawberries. * Important antioxidant. Needed for the formation of collagen fibers in CT & the conversion of tryptophan to serotonin. Aids absorption of iron. Activates folicin (B9 vitamin)

Proteins

>make up 10% to 30% of a cells mass & therefore the dominant structural material of the animal body >Purpose: used for building critical structural materials, such as keratin, collagen, & elastin for the skin; connective tissues; & muscle proteins. > Not all proteins are construction materials, many play vital & diverse roles in cell function: enzymes & hormones regulate an incredible variety of body functions: hemoglobin carries oxygen in RBCs; & contractile proteins in muscle cells enable body to move

essential nutrients

A select group of nutrients that cannot be manufactured in the body from the "building blocks" molecule: amino acids, monosaccharides, glycerol, & fatty acids. Animals must obtain essential nutrients from their diet

Triglycerides or triacylglycerols

Triglycerides-A glycercol composed of three fatty acids, which are the main storage form of water-insoluble lipids Triacylglycerols- a neutral fat; triglycerides

Studying cell metabolism

enzymes can be identified because it name ends in the suffix -ASE. The enzyme is usually named for it substrate on which it acts. Ex., PROTEINASE are enzymes that break down protein, LIPASE break down lipid, LACTASE breaks down lactose. The name of the enzyme may also indicate the kind of reaction the enzyme initiates. Ex., SYNTHETASE are enzymes the SYNTHESIZE or make new substances, TRANSFERASES are enzymes that move one part of a molecule to another molecule. PHOSPHOTRANSFERASE is an enzyme that transfers a phosphophate group from one molecule to another molecule. The names of enzymes are very useful & may indicate the biochemical reaction that are taking place.

List & describe the four categories of lipids

1. Neutral fats, aka fats-Lipids; solid and oils, composed of three chains of fatty acid molecules attachéd to a single molecule of glycerol and chain classification depends upon the # of carbon atoms in the backbone of the molecule, resembles the letter E. triglycerides - three fatty acids in each molecule of fat, SATURATED fatty acids - meat, milk, cheese, cream, butter, coconuts. UNSATURATED fatty acids- vegetables oils, olive, safflower. 2. PHOSPHOLIPIDS - plasma membrane in plant & animals cells. 3. STERIODS - eggs, butter, & cream, animal fat, some chemical insecticides in the environment. CHOLESTROL, sex hormones 4. Other lipid substances - fat soluble vitamins (Vitamins A, D, E & K), Eicosanoids - regulatory molecules derived by arachidonic acid (20-carbon fatty acid found in the plasma membrane), & lipoproteins. These substances include prostaglandins, luekotrienes, & thromboxane, hormones that play an important role in inflammatory process, blood clotting, & labor contractions. prostaglandins are also important in smooth muscle contraction & in controlling blood pressure

Two factors whether a neutral fat is solid or liquid at room temperature

1. The length of the fatty acid chains 2. The degree of saturation with hydrogen atoms within the chains

List the six categories of nutrients

1. water (H2O) - consumed in large quantities, produce no energy 2. carbohydrates - consumed in large quantities, produce energy 3. lipids - consumed in large quantities, produce energy 4. proteins -consumed in large quantities, produce energy 5. vitamins - small quantities, produce no energy 6. minerals -small quantities, produce no energy

Summary of cellular respiration

A. Glycolysis occurs in the cytoplasm, where glucose is converted to two molecules of pyruvic acid. A net production of two ATP molecules occurs. Other chemical energy in the form of two NADH molecules is produced, which is converted to ATP in the electron transport system. B. Kreb's cycle; The inner membrane of the mitochondrion has infoldings & outpouchings, called CRISTAE, which form separate " work spaces" for the Krebs cycle. Many of the enzymes involved for ATP production, such as ATP SYNTHETASE, are built into the wall of the inner membrane. These molecules form an assembly line, which improves efficiency & helps to prevent errors. The matrix that fills internal spaces of the cristae is rich with electron carriers, phosphate, coenzymes, & other solutes necessary for ATP production. C. Electron transport chain; The inner membrane of the mitochondrion houses series of cytochrome molecules, which make up the electron transport system. As electrons are passed from one cytochrome molecule to another, energy is released that is used to transport protons from the mitochondrial matrix across the inner membrane to the intermembrane space. Because protons are positive, this establishes a positive charge on the outside of the inner membrane relative to the matrix side. The electrical gradient that is stabled is a form of stored, potential energy. Energy is released when protons rush back into the mitochondrial matrix. This release of energy is the ultimate power source that converts ADP into ATP

summary Transamination & deamination

A. during transamination, an amine group of an amino acid is transferred to another molecule by the enzyme transaminase, & a different amino acid is subsequently formed. When stripped of its amine group, an amino acid becomes a keto acid. B. During deamination, an amine group is removed from the amino acid by the enzyme deaminase. Amino acid then becomes a keto acid, which can be reused in transamination reactions. The amine group is converted to ammonia, a toxin; the liver subsequently converts ammonia to a nontoxic molecule called urea.

Kilocalories (kcal)

AKA calories (C); How the amount of energy that is required nutrient molecule are measured. A kilocalorie is the amount of energy needed to raise the temperature of a kilogram of water (H2O) 1 degree

Short- chained fatty acids

Aka VOLATILE FATTY ACIDS (VFAs), these are the main energy source for ruminants. They are created by the microbial fermentation (breakdown of ingested plant matter) cellulose. Found in the gas & liquid contents of the rumen & reticulum, also in the colon of nonruminant herbivores. Common VFAs includes acetic acid & propionate

Complete proteins

Animal products (eggs, meat, & dairy) contain proteins that contain large # of essential amino acids. Meat products contains all the essential amino acids for many species & therefore called - COMPLETE PROTEINS >Animal-based proteins are more expensive than plant-based proteins, so many pet-foods contain primarily plant-based proteins, like soy. >Cereals, rice, nuts & legumes-beans, are protein-rich, but their proteins are nutritionally incomplete, because they are low in one or more of the essential amino acids. Leafy green vegetables are also rich with essential amino acids, but have little methionine & tryptophan. When digested together, legumes, grains, & cereals provide all of the essential amino acids for many species, including humans: these foods are therefore said to be COMPLEMENTS OF ONE ANOTHER.

Flavin adenine dinucleotide (FAD)

Are commonly encountered coenzymes in the cell & are critical in powering important cellular functions

Minerals

Are inorganic substances that are essential for life, though they make up less than 4% of an animal's body by weight. Like vitamins, minerals do not generate energy, but they work with other nutrients to ensure that the body functions normally. They are classified as MACROMINERALS, MICROMINERALS, & TRACE ELEMENTS, depending upon how much of them is required by the body; however, the amount of a particular mineral in the body does not tell you how important that mineral is. Ex., iodine is needed in extremely small quantities, yet it is vital for normal thyroid function, which controls metabolic rate. >Macrominerals, calcium & phosphorus at the most abundant in the body & compose 3/4 of the minerals by weight. Together with magnesium salts, harden the teeth & form the rigid, hard material that gives bone its strength. Sodium & chlorine are primary electrolytes found in the blood, vital for maintaining normal oncortic pressures in the body & for assisting in H2O absorption in the kidney. >Microminerals, Iron is one of the most vital, because it is the core of the hemoglobin molecule that carries oxygen in RBCs. Without iron, cells could not receive oxygen needed to make ATP, & animal would die >Trace elements, fluorine is perhaps the most well-known, because of its importance in healthy teeth

unsaturated fatty acids

Breakdown products of fat metabolism. Unsaturated refers to the fact that not all the chemical binding sites of the molecules are filled. They have one or more double bonds in their carbon chains & are liquid at room temperature. If one double bond is present, the fatty acid is mono saturated . More than one double bond is present, the fatty acid is polyunsaturated. Ex., are found in plant oils (mono- oliver & peanut oil & poly- corn, soybean, & safflower oil contain high%) & include arachidonic, linolenic, & oleic acid > double bonds cause the chains to bend & kink

Summary of nutrient groups & their dietary sources

Carbohydrates -sugars; simple carbohydrates (monosaccharides & disaccharides) found in fruit, honey, sugar cane, sugar beets, & immature vegetables >Starches - complex carbohydrates (polysaccharides) found in grains, nuts, rice & root vegetables, such as potatoes & legumes >Cellulose - complex carbohydrates (polysaccharides) found in most vegetables >Proteins- Meat, dairy products, soybeans, green leafy plants, eggs >Lipids -neutral fats; SATURATED - meat, milk, cheese, cream, butter, coconuts. UNSATURATED- vegetables oils, olive, safflower. PHOSPHOLIIPDS - plasma membrane in plant & animals cells. STERIODS - eggs, butter, & cream, animal fat, some chemical insecticides in the environment. CHOLESTROL > other lipoids substances- dark leafy vegetables, root vegetables, some animal sources; FATS- soluble vitamins, EICOSANOIDS ( regulatory molecules derived from arachidonic acid) prostaglandins, leukotrienes, & thromboxanes. LIPOPROTEINS

List & describe the three categories of carbohydrates

Carbohydrates -sugars; simple carbohydrates (monosaccharides & disaccharides) found in fruit, honey, sugar cane, sugar beets, & immature vegetables Starches - complex carbohydrates (polysaccharides) found in grains, nuts, rice & root vegetables, such as potatoes & legumes Cellulose - complex carbohydrates (polysaccharides) found in most vegetables

describe the processes of catabolism Stage one

Catabolism occurs in three stages: 1. in the lumen of the gastrointestinal tract, 2. occurs in the cytoplasm (cytosol). 3. occurs in the mitochondria >Stage one - food is broken down in the stomach & in the first part of the small intestine, the duodenum. The digested stomach contents (chyme) passes into the small intestine. Here the food is broken down further by enzymes in the lumen of the intestine. In addition, the cell membranes in the microvilli brush border produce more enzymes, also H2O, vitamins, & minerals are also derived from food & carbs, proteins, & fats are further broken down, or catabolized the nutrient molecules into their building block units. . This part of the catabolic process is call HYDROLYSIS (hydro -H2O & lysis -to break down). At least one molecule of H2O is used up each time a nutrient molecule is broken down. Hydrolysis is the first stage of catabolism. A large sugar molecule (polysaccharide), can be broken down into disaccharides, and the disaccharides, can be hydrolyzed into two smaller sugar molecules called monosaccharides: (1 disaccharide + H2O ->1 monosaccharide + 1 monosaccharide). Proteins are broken down into amino acids; carbohydrates into monosaccharides; nucleic acids into nucleotides; & fats into fatty acids .Once it is complete, the smaller nutrient molecules monosaccharides, fatty acids, glycerol, & amino acids are taken up by the absorptive cells. The nutrient molecules are then transported through the absorptive cell & are taken up by capillaries (amino acids & sugars) or lacteals (fatty acids) in the villi. Once in blood or lymph, nutrient molecules are carried quickly away from the gastrointestinal tract. Most of the nutrient-rich blood flows directly to the liver via the hepatic portal vein, where the nutrient molecules are either incorporated into the production of larger molecules, or are further broken down. From the liver, nutrients continue to travel through general circulation to other body tissues. Cells through out the body absorb the nutrient molecules from blood & lymph. Once in the cytoplasm the molecules can undergo the second stage of metabolism

Metabolism

Cell metabolism is divided into two categories: CATABOLISM & ANABOLISM >Catabolism is a process that involves BREAKING DOWN nutrients into smaller molecules to produce energy. Energy is stored into bonds of the ATP molecule, which can be transported to other cell where it is needed. > Anabolism is a process in which the stored energy is used to ASSEMBLE new molecules from the small components that are produced from catabolism. > catabolism & anabolism reactions occur simultaneously, & each must be in exquisite balance with the other so that adequate levels of energy are maintained

Neutral fats (NFs)

Commonly known as FATS when solid and OILS when liquid. Fats are a kind of lipid, but not all lipids are fats. >building blocks of NFs are FATTY ACIDS & GLYCERSOL. Fatty acids are linear molecules classified as LONG-, MEDIUM-, SHORT-CHAINED FATTY ACIDS depending upon # of (C) atoms

Vitamins

Consumed in minute amounts, vitamins are essential for life. Latin word VITA means life. Unlike nutrient molecules (carbohydrates, proteins, & fats), they produce no energy when metabolized, nor are they broken down into building-block units. > They are coenzymes or parts of coenzymes, their molecular structure is the "key" that activates an enzyme & enables it to carry out its diverse metabolic reaction. Ex., Biochemical breakdown of glucose, B vitamins riboflavin & niacin are required. Without them, reaction cannot be completed & glucose cannot be used to generate energy. > Thus, the full use of nutrient proteins, carbs, & fats is dependent upon the presence of coenzymes. But not all vitamins are coenzymes. Vitamins A, D, & E; Vitamin D is used to regulates calcium levels in the body: & a form of vitamin A, retinol, helps sensory cells in the retina of the eye to detect light. Vitamin E is an important antioxidant > plants can manufacture the vitamins they require, but animals cannot. Therefore most vitamins are not made in the body & so must be consumed in the diet. But there are exceptions; Vitamin D, is made in the skin, Vitamin K & biotin is made in the intestine by bacteria. In addition, the body convert bets-carotene, an orange pigment found in carrots & deep green leafy vegetables, into vitamin A. Beta-carotene is called a PROVITAMIN and is essential for many species

anaerobic glycolysis

DEF: An alternative expression for glycolysis, referring to the fact that reaction does not require oxygen

Coenzymes

DEF: An organic molecule that is required by an enzyme to carry out a metabolic reaction. Coenzymes, such as nicotinamide adenine dinucleotide (NAD), are often derived from vitamins

Cofactors

DEF: Elements, such as coenzymes, that act concurrently with another element to carry out chemical reactions

Nicotinamide adenine dinucleotide (NAD or NADH)

DEF: The coenzyme used in many oxidation-reduction functions. When oxidized, it is written as NAD. In its reduced form, having given up an electron, it is written as NADH

cellular respiration

DEF: The oxidation of organic material to yield energy (ATP), carbon dioxide (CO2), & water (H2O)

Transamination

DEF: The process of amino group transfer to other amino acids or within the same compound > The amine group (--NH2) is transferred to another carbon chain to form a different amino acid. The newly constructed amino acid then diffuse across the mitochondrial membranes into the surrounding cytosol, where it becomes the building blocks for other proteins

Anabolism

Def; The form of metabolism by which cells build complex compounds from simpler ones; the opposite of catabolism. The process by which the cell uses energy to manufacture large molecules from smaller ones; these molecules are used to maintain the cell & carry out metabolic processes

Positive nitrogen balance

DEF: When the amount of protein ingested is greater than the amount excreted. > occurs when the body is incorporating more protein into tissues than it is breaking down to make energy (ATP). happens normally during healing & during pregnancy because of the growing fetus. Also occurs in growing animals, certain hormones -ANABOLIC HORMONES, accelerate protein synthesis & growth. ex., pituitary glands hormone stimulates tissue growth in young animals & conserves proteins in the mature. Sex hormones trigger growth spurts. Growth & lactation increase the protein requirements above what is needed for body maintenance & exertional work or exercise > the metabolism of excess amino acids increases of the liver & kidney due to the processing & excretory requirements for the urea & organic acid waste byproducts. In other words, eating too much protein causes liver & kidneys to work harder. Animals with kidney disease are fed a low protein diet.

Myositis

DEF:Inflammation of a voluntary muscle that causes pain & stiffness >Occurs when lactic acid builds up in muscles during & after exercise & causes a stiff feeling the next day. Oxygen (aerobic respiration) is depleted in the skeletal muscle cells from vigorous exercise, cells choose a different metabolic pathway & converts pyruvate to lactic acid > In horses, this stiffness can be severe & cause myositis or tying up, not uncommon for this to occur in horses ridden for pleasure (weekends) aka Monday morning syndrome

Deamination

DEF:The process during catabolism in which the amino group NH2, is removed >The amine group is removed from the carbon chain & becomes ammonia molecule, which is toxic, occurs in the liver, where specialized enzymes are present to convert ammonia to UREA, a non toxic water-soluble molecule that is excreted in urine. > After amine removal, the remaining carbon chain may enter the Krebs cycle from at one of several location, resulting in the formation of ATP. Some of the pathways for ex., enter the Krebs cycle from the formation of acetyl CoA, others enter much later. resulting to a variable rise of the amount of ATP, depending on where the cycle entered. If energy is not used immediately, the carbon chains may not enter the Krebs cycle but instead be converted to glucose or fat.

Product molecules

DEF:The product of an enzyme reaction caused by the enzyme's ability to weaken the bonds of the substrate molecule

Phospholipids

Def: A molecule composed of three parts: PHOSPHOROUS, FATTY ACIDS, & NITROGENOUS BASE, any lipid that contains phosphorus. Phospholipids are the main components of the cell membrane. >modified triglycerides derived primarily from the cell membranes of plant & animal cells . Like triglycerides, phospholipids contain two, rather than three, fatty acid chain; therefore could be call DIGLYCERIDES. > Have a phosphorus group attached to the glycerol molecule -POLAR HEAD, molecule (polar head & 2 fatty acid chains) [resembles head, shoulders, & dropped arms of a stick person.]

Essential amino acids

Def: An amino acid that cannot be produced in sufficient amounts; therefore it must be obtained through diet. Different species have different essential amino acids needs. Ex., dogs can do well- on home-cooked vegetarian diets, as well as on meat-based diets, if adequate complement foods are present, but cats are strict carnivores & must consume animal proteins (because taurine is found naturally only in animal tissue). Therefore, cats should not be fed a home-cooked vegetarian diet.

Nonessential amino acid

Def: An amino acid that is produced in the body in sufficient amounts: it does not have to be supplemented by diet, Different species produce different nonessential amino acids; therefore what may be nonessential in one species may be essential in another.

cytochromes

Def: Essential to the final stage of the electron transport system, this copper-containing complex of enzymes transfers electrons to oxygen. The oxygen in turn can bond with hydrogen, thus producing water.

electron transport chain

Def: The final & most productive stage of cellular respiration, which takes place inside the mitochondria

Crude proteins (CP)

Def: The total nitrogen content of a feed multiplied by 6.25. The CP gives a close approximation of the protein content in a particular feed >Pet food labels identify the CP contents, most people assume the best food has the highest percentage of crude protein. This is not necessarily true, CP gives no indication of the quality or utilization potential of the protein. Ex., a dog food may have a high protein content, but the BIOLOGIC VALUE of the protein is low. > Biologic valve - is the percentage of absorbable protein that is available for the productive body functions, defines the amount of amino acids available for metabolic process. The idea protein content should include all the essential amino acids needed to meet the specific metabolic requirements of a particular species. Ex., if a protein has a missing essential amino acid, its quality may be low, by adding the missing amino acid, the full potential of the biologic value of the protein can be restored. This is why mixed animal & plant protein sources are often complementary to each other in food formulations. The quality of proteins is improved if feeds are not over processed or overheated in storage, heating can denature proteins.

negative (nitrogen) balance

Def: When the rate of protein loss in feces and urine exceeds the amount of protein ingested > occurs when protein breakdown exceeds the amount of protein being incorporated into tissues. Occurs during physical & emotional stress, infection, injury, debilitation & during starvation, or when the quality of the dietary protein is poor. > Glucocorticoids released during stress enhance protein breakdown & the conversion of amino acids to glucose. Cats are the consummate carnivore & are specifically adapted to high protein diets. They commonly manufacture proteins from the amino acids released from gluconeogenesis.

Nitrogen balance

Def: when the rate of protein synthesis equals the rate of protein breakdown in the healthy animal. In other words, the amount of nitrogen ingested in the form of protein equals the amount excreted in urine & feces > nitrogen from protein is packaged by the liver as a molecule called BLOOD UREA NITROGEN (BUN) before it is excreted by the kidney

aerobic respiration

Def:The cell function that produces chemical energy (ATP) with the use of oxygen > occurs in the mitochondria in TWO STAGES: the KREBS CYCLE (aka Citric acid cycle) & the ELECTRON TRANSPORT CHAIN

Provitamin

Def; a molecule from which an animal can manufacture, a vitamin such as beta-carotene

Fat-soluble vitamins list their dietary sources & functions

Fat soluble vitamins are stored for long periods of time in tissues. Excess is not excreted, making toxicity a possibility if high levels are consumed > VITAMIN A (RETINOL)- -Can be formed in the body from ingested beta-carotene, which is found in dark green leafy & dark yellow vegetables. Also found in fish oil, milk, eggs, & liver. * 90% is stored in the liver, so feeding liver routinely to dogs & cats can cause toxicity. Enough is stored to meet the body's needs for one year >VITAMIN D (ANTIRACITIC FACTOR OR CALCIFEROL) - Formed in the skin when UV lights converts 7-dehydrocholesterol. Modified to the active form in the liver & kidneys. Also found in liver oils, eggs, & fortified milk. *Essential for blood clotting & bone & tooth formation. Acts as a hormone that regulates calcium levels in the blood by increasing absorption from the gut & mobilizing calcium from bones >VITAMIN E (ANTISTERILITY FACTOR OR TOCOPHEROLS) -Found in wheat germ, nuts, whole grains, vegetable oils, & green leafy vegetables. Stored in muscle & fat tissue; chemically similar to sex hormone. *An important antioxidant. Prevents oxidation of unsaturated fatty acids & cholesterol;. Helps prevent oxidative damage to cell membranes. > VITAMIN K (COAGULATION FACTOR OR QUINONES) -Found in leafy green vegetables, cauliflower, broccoli, pork liver, & cabbage. Also is synthesized by bacteria in the large intestines of some species * Essential for the generation of clotting factors & many proteins made by the liver. Contributes to the process of oxidative phosphorylation in cells

describe the process of the electron transport system

Final stage of cellular respiration; Cytochrome molecule are located in the inner membrane of the mitochondrion. Each cytochrome molecule contains a central iron core that accepts electrons & then releases them to another cytochrome molecule at a lower energy level. At each step, a large amount of free energy is used to pump protons from the matrix through the inner membrane to the intermembrane space, because more protons are pumped to the outside than remain on the inside of the inner membrane. Energy is released when the protons flow back to the matrix side. This energy is used to convert ADP to ATP. The low-energy electrons left at the end of the cytochrome chain & the hydrogen atoms in the matrix bind to Oxygen & form water (H2O) Produces the majority of ATP for the cell

Building blocks

Large molecules that make up carbs, fats, & proteins are broken down into fundamental building blocks to make new & different molecules. This process is the foundation of nutrition & cell metabolism > potatoes, meat ->dog food ->Large molecule (carbs, fat, proteins) Breakdown to ->medium sized molecules CARBS -> (polysaccharides -> disaccharide), FATS ->(triglyceride) & PROTEIN -> (polypeptide -> dipeptide) breakdown to Small fundamental "Building Block" molecules DISACCHARIDE-> (2 monosaccharide molecules), TRIGLYCERIDE -> (glycerol molecule + 3 fatty acid molecules) & DIPEPTIDE -> ( 2 amino acid molecules). Absorbed by the absorptive cells that line the intestine & taken up by capillaries & put into the blood supply.

Steriods

Lipids dramatically different from neutral fats, made of four flat interlocking rings of hydrocarbons. Includes cholesterol, bile, salts, sex hormones, & hormones released from the cortex of the adrenal gland. Cholesterol is the most nutritionally, because all of the other steroid molecules can be made from cholesterol: it is the essential precursor. > like phospholipids, cholesterol is found in the plasma membrane, is nutritionally derived from animal products (egg yolks, meat, & cheese). In addition, the liver is able to manufacture cholesterol; without it, animals would not be able to carry out many vital biochemical processes

list the common macrominerals, micromineral, & trace elements found in the body

MACROMINERALS -calcium (Ca), chlorine (Cl), magnesium (Mg), phosphorus (P), potassium (K), & sodium (Na). Expressed in parts per hundred (1pph=10 grams per kilogram of food) MICROMINERALS- copper (Cu), iodine (I), iron, (Fe) manganese (Mn), selenium (Se), & zinc (Zn). Expressed in parts per million (1ppm=1milligram per kilogram of food) TRACE ELEMENTS(MINERALS)- chromium (Cr), cobalt (Co), fluorine (F), molybdenum (Mo), nickel (Ni), silicon (Si), sulfur (S), & vanadium (V).

Simple sugar

Monosaccharides, such as glucose & fructose

Carbohydrates

Primarily derived from plants. Fundamental building block of carbohydrates is the monsaccharide. Glucose, most important monosaccharide- .1. May be composed of straight chain atoms, 2. or it may bend into a more stable ring. 3. 3-D appears as a tight cluster of atoms. 4. monosacchrides link together to form disaccharides (di means two) or polysachides ( poly means "many")

Summary of ATP Synthesis

Production from one glucose molecule > a maximum of 38 ATP molecules are formed by an animal, some cells form 36 ATP molecules. Two ATP molecules are made in the cytoplasm, & the rest in the mitochondria > In the cytoplasm, glycolysis -> two molecules of ATP, Two NADH (electron transport) produces six ATP (three for every molecule of NADH). In certain cells, each NADH produces only two ATP instead of three; glycolysis produces only six ATP, not eight.[8 ATP] > Inside the mitochondria; pyruvic acid is converted to acetyl CoA before entering the Krebs cycle & two NADH are formed forming six ATP molecules [6 ATP] Also, occurring the Krebs cycle yields two ATP molecules, two FADH2, [ 4 ATP] & six NADH [18 ATP]. The electron transport system converts the NADH & FADH2 molecules into 22 ATP >once formed, the energy-carrying ATP molecule are exported across the mitochondrial membrane, & a molecule of ADP is brought into the mitochondria for each ATP exported

membrane proteins

Proteins imbedded in the cell's membrane caused by the different concentrations of positive & negative charges ex., cell receptors & membrane transport molecules, & osmoregulators

Protein Catabolism

Proteins may be catabolized & used to make energy (ATP) >Protein from food is digested into amino acids, but before they are completely catabolized, the amino group (NH2) is removed & converted to ammonia (toxic to the body), which is later excreted in urine. [Protein ->(liver) -> ammonia->(kidney)->urea-> urine] The remainder of the deaminated portion is then converted to acetyl CoA & subsequently is used to generate ATP >Amino acid catabolism occurs in most tissues, it is of particular importance in the intestinal mucosa, kidney, brain, liver, & skeletal muscle, where amino acid molecules may undergo one of two processes : DEAMINATION or TRANSAMINATION

protective proteins

Proteins that are a compound of the immune response, such as antibodies

Contractile proteins

Proteins that are essential to muscle contractions, such as myosin & actin in muscle tissue

storage proteins

Proteins that are stored for later use, such as those found in egg whites

Structural proteins

Proteins that form body structures, such as hair, microtubules & collagen

osmoregulators

Proteins that regulate & adjust the osmotic pressure between the cell & extracellular fluids. Ex., include albumin & enzymes

Transport proteins

Proteins that transport substances, such as hormones, from their origin to where they are needed ex., hemoglobin & myogloin

list the events that occur in each stage of cellular metabolism

Stage 1: GASTROINTESTNAL TRACT -small fundamental "building block" molecules absorbed by intestine. Large nutrient molecules from food are degraded by enzymes & emulsifiers in the lumen of the stomach & intestine. Much smaller molecules are formed, which are absorbed, through the intestine & transferred to blood & lymph. They are transported to various parts of the body. Stage 2: CYTOPLASM OF THE CELL- no oxygen needed at this stage (ANAEROBIC CELLULAR RESPIRATION). Tissue absorb the small building-block molecules from the bloodstream. In the cytoplasm of the cell, the small molecules may be either used to make larger molecules (ANABOLISM) or broken down into even smaller molecules, such as pyruvic acid & acetyl CoA (CATABOLISM). Stage 3: MITOCHONDRIA OF THE CELL; oxygen is needed at this stage, so the animal must breath for this part to work (AEROBIC CELLULAR RESPIRATION). This stage is entirely CATABOLIC: acetyl CoA is transported to the mitochondria of the cell, where it is broken down in the KREBS CYCLE. The hydrogen atoms that result are channeled into the ELECTRON TRANSPORT CHAIN, where ATP is produced via oxidative phosphorylation

describe the processes of catabolism:: Stage three mitochondria

Stage three is the final stage of catabolism. Acetyl CoA is transported to the mitochondria from the cytosol where AEROBIC RESPIRATION (aerobic - using oxygen) & involves the attachment of an inorganic phosphate group (PO4) to a molecule of ADENOSINE DIPHOSPHATE (ADP). The result is the formation of ADENOSINE TRIPHOSPHATE (ATP). A critical molecule used in the cell to carry much of the energy that is derived from food; this energy is essential for making new molecules. > The mitochondrion can be viewed as an energy-producing factory: much of the energy that is derived from food is stored in the bonds of the ATP molecule

describe the processes of catabolism: stage two Cytosol

Stage two occurs inside the cells of tissues; in the cytoplasm, in the cell's cytosol. Amino acids, monosaccharides, fatty acids, & glycersol enter cells & are further catabolized in the cytoplasm through the process called ANAEROBIC RESPIRATION, (an -not, aerobic -using oxygen), a metabolic process that does not use oxygen. Resulting in an important molecular product of acetyl CoA, which carries a lot of energy from food: acetyl CoA is transported through the cytosol to the mitochondria, where it is used in AEROBIC RESPIRATION.

Energy of activation

The energy needed to initiate a biochemical reaction. Most chemical reactions require an input of energy to get started. >Heat- is used in the lab as an energy activation; causes molecules to become more active & to bang into one another, collision cause existing bonds to be broken & new bonds to be formed, resulting in the creation of new substrates. However heat can be harmful to organelles & other structures with in the cell. Heat would affect all the chemical reactions at once & would don't be selective for a particular type of reaction. Cells rely on enzymes to initiate & control metabolic reactions.

catalysts enzymes

Substrates that speed up the reactions by lowering the activation energy; enzymes bring reactant substrate molecules into proximity of one another & form temporary associations with them, them are able to speed up the rate of molecular reactions > Heat & various elements, ions, & chemicals can also act as catalysts. The rate at which a catalyzed reaction occurs is related to the amount of substrate & enzyme present. In general, an increase in the amount of an enzyme or a substrate causes an increase in the rate of the reaction. > in addition, different enzymes have varying innate rates; one type of enzyme might perform fewer reactions per second than another type of enzymes

Saturated fatty acids

Such as those found in animal fats; have no double bonds in their carbon chains & can therefore accommodate the maximum # of hydrogen atoms; are solid at room temperature > tend to be long chains & primarily found in meat & dairy food; milk, cream, cheese, lard, & butter. Coconuts are one of few plant sources of saturated fats

phosphorylation

The addition of phosphorus into an organic compound

Crude proteins (CP) in ruminants

The digestion of protein is facilitated by microbes, which break down protein derived from the grasses & grains consumed in the diet. Amino acids generated from this process are further degraded into ammonia, organic acids, & CO2. The ammonia is either absorbed through the wall of the rumen or is used by the microorganisms to make new proteins > Interestingly, the microbial-made protein has a consistent quality regardless of the quality of the nutrient source. Thus, protein in lower-quality feeds is improved by microbial metabolism. On the other hand, high-quality protein from feed may be lowered by microbial metabolism; so feeding a high-quality protein to a ruminant may give the same results nutritionally as feeding it a low-quality protein. > The rumen also has the ability to convert non-protein sources of nitrogen, such as urea & ammonium salts, into protein. These nitrogen sources, however must be used judiciously in feeds because an excess or an imbalance can be toxic to the herbivore

mitochondrial matrix

The enzyme-rich liquid in the mitochondria that surrounds the cristae & provides them with the enzymes necessary for the proper function of the Krebs cycle

Lipid metabolism

The liver is the primary controller of lipid metabolism; lipids are molecules composed of carbon, hydrogen, & oxygen, insoluble in water but dissolve easily in other lipids or organic solvents. > One common type of lipid - TRIGLYERIDES or NUETRAL FATS, higher # of carbon-hydrogen bongs than other nutrient molecules, contain more chemical than either carbs or proteins, because energy is stored in the bonds between atoms. Gram for gram, fat contains over twice as much energy as carbs, & stores six times as much energy as glycogen. Important in birds, illustrates fat concentrates energy in a form that is relatively lightweight-essential for flight. Herbivores do not consume the large amount of fat that is prevalent in the diet of meat eaters. Their formation of fat derived primarily from the conversion of carbohydrates in excess of what can be stored as glycogen. > Triglyceride metabolism - triglyceride from food are digested into glycerol & fatty acids. These can be further broken down to form acetyl CoA, which enters the Krebs cycle to form ATP. Excess nutritional triglycerides not immediately catabolized for energy are stored in tissue as fat. >Fat for the most part, is not soluble in water & is difficult to mobilize, it serves primarily as a reserve energy source, rather than a supply to meet immediate energy demand. Not immediately used to produce energy, glycerol & fatty acid chains may be reconstructed into lipids & stored in fatty tissue > Nature's way of protecting the health of animals & humans when food supplies become low.

Beta oxidation

Triglyceride that been hydrolyzed into one molecule of glycerol & three fatty acid chains. The glycerol head is catabolized in the cytoplasm to acetyl CoA. The fatty acid tails, which are long chains of 18 carbon atoms or more are handled by enzymes found in the mitochondria. >The process of BETA OXIDATION, each fatty acid chain is broken into multiple, two-carbon fragments. Some fragments are into converted to acetyl CoA, whereas others are converted compounds called KETONE BODIES >Later, the ketones can be converted to acetyl CoA which can be further catabolized in the Krebs cycle to form ATP. Energy gained from the complete oxidation of an 18-carbon fatty acid chain is substantial about 148 ATP, which is 4xs more energy than generated from the catabolism of one molecule of glucose.

Describe the process of Anabolism

The process of anabolism work simultaneously with catabolism as nutrients are absorbed through the cells.The smaller molecules along with ATP from catabolism construct larger, complex molecules needed for many aspect of cellular life. An important part of anabolism is DEHYDRATION SYNTHESIS, opposite of hydrolysis. The combination of two or more simple materials to form one or more complex materials by removing H2O. ex., two monosaccharides can combine to form a disaccharide (Glucose + galactose = Lactose +water). Glycerol & fatty acid molecules are connected to form fat molecules, & proteins are created from chains of amino acids. >Many of the anabolic cellular processes occur during stage two of metabolism. Here, the building blocks glucose, glycerol, fatty acids & amino acids are incorporated into larger molecules, which may be used by the cell itself or exported & used elsewhere in the body. >The liver is an important organ because of its active anabolic efforts; it manufactures proteins such as albumin & clotting factors, & it manufactures & stores glycogen & fat.

Active site

The region of the enzyme molecule that binds to the substrate. Like other portions of the enzyme, the active site is flexible & can exert pressure on the substrate that, in turn, weakens the bonds that keep the substrate molecular intact., forming one or more PRODUCT MOLECULES. which subsequently separate > In biosynthesis reactions, enzymes unite smaller molecules to form large molecules, theses enzymes require more than one active site. The enzyme is not altered by the reactions that it initiates & is able to move on to other substrate molecules to complete more of the same kind of reaction. >Enzymes can bind to one substrate to produce two product molecules via catabolism. Also, can bind to two substrates to form a single product molecule via anabolism

Essential & non essential amino acids

There are 10 essential & 12 nonessential amino acids in most species. >ESSENTIAL AMINO ACIDS- must be present in the diet because the animal either cannot make them at all or cannot make them fast enough to meet the body's needs for tissue maintenance & growth. To make new proteins, all of the needed amino acids; essential & nonessential must be present in the cell in SUFFICENT QUANTITY & ALL AT THE SAME TIME. >Amino acids cannot be stored. those not used to make proteins are oxidized by the cell to make energy or are converted to carbohydrate or fat calories in the diet to make ATP, then the cell will use proteins from the diet or will catalyze tissue to make ATP

regulatory proteins

Those proteins essential to maintaining normal body function with insulin & many other hormones

Essential fatty acids

Unsaturated fatty acids such as linolenic, arachidonic, & linolenic fatty acids that are necessary for normal body functiond yet are not synthesized by the body in sufficient amounts; therefore they must be supplemented by diet. > the liver is adept at converting one fatty acid to another; but some fatty acids, such as linoleic acid, cannot be synthedized. It is possible for the body to convert linoleic acid into arachidonic acid, process is extremely inefficient & inadequate yield results for many species.

Differentiate between the water-soluble vitamins & fat-soluble vitamins.

Water soluble vitamins are absorbed through the gut wall when water is absorbed in the gastrointestinal tract. They include vitamin C & eight of the B-complex vitamins. An exception is vitamin B12, however which must bind to gastric intrinsic factor before it can be absorbed. Very small amounts of water-soluble vitamins are stored in the body, & excesses not used within an hour are excreted in the urine. Hypervitaminosis conditions of water-soluble vitamins are therefore extremely rare.. > fat-soluble vitamins include A, D, E, & K. these bind to ingested lipids before they are absorbed with ingesta. Thus, if fat absorption is impaired, so too is the absorption of fat-soluble vitamins. Except for vitamin K, fat-soluble vitamins are stored in the body; so if excessive amount of fat-soluble vitamin is consumed, vitamin toxicity due to hypervitaminosis may result. Vitamins A,C, & E are potent antioxidants that disarm dangerous free radicals. Certain foods such as broccoli, cauliflower, cabbage, & Brussels sprout are all good sources of vitamin A &C. Vitamin D is made in the skin

temporary enzyme-substrate complex

When the enzyme & substrate binds together; An enzyme's ability to locate & bond to a particular substrate depends on the molecular SHAPE of the enzyme. Enzymes are globular proteins that consist of one or more flexible polypeptide chains. The chains twist & coil to form a unique, 3D shape that fits the special shape of the substrate molecules.

ATP conversion to ADP

When the terminal phosphate bond in an ATP molecule is broken, it releases stored energy that can be used by the cell to make other molecules. The remaining molecule, ADP , has two remaining phosphate groups

describe the process of glycolysis

anaerobic respiration; In glycolysis (sugar splitting), a six-carbon glucose molecule is split into a pair of three-carbon molecules of pyruvic acid (pyruvate). This process includes 10 biochemical steps & produces six-energy-holding molecules: two molecules of NADH & four molecules of ATP. since two molecules of ATP were used in phase one, the net production of energy is two molecules of NADH & two of ATP. Occurs in three phases: PHASE 1(Energy investment uses ATP)- one ATP molecule is used in the process of adding a phosphate molecule to glucose, which results in the formation of glucose 6-phosphate (G6P). this process is called PHOSPHORYLATION. Important in preventing the glucose molecule from leaving the cell: Phosphorylated glucose cannot cross the cell membrane & also prepares the glucose molecule for further manipulation, either catabolism or anabolic pathway. Subsequently, G6P is rearranged to form fructose-6-phosphate, Phosphorylation occurs again, using one ATP molecule to form fructose1, 6-diphosphate. PHASE 2: (cleavage of sugar) Fructose 1, 6-diphosphate is cleaved; forming a pair of three-carbon molecules, but they can be one of the two reversible isomers: BISHYDROXYACETONE PHOSPHATE &GLYCERALDEHYDE PHOSPHATE.. The molecules change back & forth between these two forms PHASE 3: (formation of ATP via oxidation of sugar) - This phase includes six steps, which results of four ATP molecules & two molecules of pyruvic acid.

describe the process of the Krebs cycle

cellular respiration; Pyruvic acid is converted to acetyl CoA, which in turn enters the Krebs cycle in the matrix of the mitochondrion. Carbon & oxygen are released from the cycle as waste & are ultimately exhaled by the animal in the form of carbon dioxide (CO2). For every molecule of glucose, the Krebs cycle can run twice (2x) & in doing so produces two molecules of ATP, two of FADH2 & six of NADH. From these energy-carrying molecules, hydrogen atoms are released & used in the electron transport system to produce ATP

thermolabile enzymes

enzymes that are affected by changes in temperature & are therefore changed in structure themselves Ex., Siamese cat, a thermolabile enzyme that affects coat color functions well in cooler temps but rendered nonfunctional in higher temps: dark brown or black pigment is produced in the cooler regions of the body. (tip of ears & tail, face. & paws), but not in warmer areas (torso, neck, & thighs). Also, Himalayan rabbits carry thermolabile enzymes.

Explain the role of enzymes in initiation & control of metabolic reaction

molecular reactions initiates & controlled by the formation & use of specialized proteins called -EMZYMES. >Each enzyme reacts with a particular molecule called a SUBSTRATE to produce a new molecule called a PRODUCT > one enzyme reacts only with one substrate or combination of substrates, enzymatic reactions are considered highly specific. > metabolism therefore is a multi-enzyme sequence of events in which the product of one step is the substrate of the next. Metabolic pathways include as many as 20 enzyme-driven steps. Many of these pathways are linear, some are circular & all have branches leading into an & out of them.