METABOLISM CHAPTER

Skeletal Muscles store _____% of Glycogen.

75% and the rest is stored in Hepatocytes

Krebs Cycle (Citric Acid Cycle)

A step in Cellular Respiration and occurs in the Matrix of Mitochondria. It forms CO2 which is transported to lungs and exhaled, production of reduced coenzymes NADH & FADH2 containing stored energy, the generation of GTP which is a high energy compound that is used to produce ATP.

Acetyl Coenzyme A is involved in?

Acetyl coenzyme A is involved in: -Helping 2-carbon acetyl groups enter the Krebs cycle -Synthesis of lipids only certain lipids like fatty acids, ketone bodies, cholesterol.

Heat is transferred from the body to the environment by?

Heat is transferred from the body to the environment by conduction, convection, radiation and evaporation.

Oxidation-Reduction Reactions

One category of reactions important in energy transfer. This reaction is always coupled; and as one substance is oxidized, another simultaneously is reduced. (Redox reaction)

Glycogen come from?

Pancreatic Alpha Cells

Insulin comes from?

Pancreatic Beta Cells and Inhibits Lipolysis

Production of lactic acid occurs under what conditions?

Pyruvic acid is converted into lactic acid under anaerobic conditions, when oxygen is in short supply in tissue.

Pyruvic acid is involved in?

Pyruvic acid is involved in -Production of lactic acid -Production of alanine -Gluconeogenesis

Triglycerides stored in adipose tissue constitute ____% of all body energy reserves.

Triglycerides stored in adipose tissue constitute 98% of all body energy reserves.

Electron Carriers of Electron Transport Chain

- Flavin Mononucleotide (FMN) Flavoprotein derived Riboflavin (vit B2) - Cytochromes b,C1,C A, A3 proteins, alternating reduced form Fe2+ - Iron-Sulfur Centers form electron transfer center - Copper Atoms participate electron transfer - Coenzyme Q nonprotein, low wt molecule

Acetoacetic Acid

Made by Hepatocytes and can not be used for ATP production because is lacks Coenzyme A to transfer back.

Name the Four classes of Lipoproteins?

1. Chylomicrons- Transport dietary lipids to adipose tissue 2. Very-low-density lipoproteins (VLDLs) transport triglycerides from Hepatocytes to adipocytes. 3. Low-density lipoproteins (LDLs) carry about 75% total cholesterol (Bad Cholesterol when elevated) delivered to cells to repair cell membrane, steroid synthesis and bile salt. 4. High-density Lipoproteins (HDLs) Good cholesterol decreases risk of CAD.

How many ATP molecules are generated for each molecule of glucose Catabolized?

30-32 ATP molecules

Adipose tissue is used to remove ______ from Chylomicrons and VLDLs, and is constantly broken down and resynthesized.

Adipose tissue is used to remove triglycerides from Chylomicrons and VLDLs, and is constantly broken down and resynthesized.

Chemiosmosis

Apart of Electron Transport Chain. Responsible for most ATP produced during cellular respiration. This mechanism links chemical reactions with the pumping of hydrogen ions.

Lipoproteins

Because lipids are nonpolar and hydrophobic they do not dissolve in water. They must be transported by combining lipids with proteins & is produced in the liver and intestines. Blood plasma is over 90% water therefore, transport is needed. There are four classes of Lipoproteins.

Name some Completed Proteins that contain sufficient amounts of essential amino acids.

Beef, fish, poultry, eggs and milk are complete proteins.

During fasting and starvation ketones bodies are used for?

Cells use Ketone bodies as energy.

Cholesterol comes from some foods such as eggs, dairy, organ meats, but most are synthesized by _________ and is a ________ process.

Cholesterol comes from some foods such as eggs, dairy, organ meats, but most are synthesized by Hepatocytes and is a endogenic process.

Endergonic

Consume more energy than they produce.

Acetoacetic acid is made by Hepatocytes, and can not be used for ATP production, because they lack coenzyme A to transfer back, however, ____, ___, _____ prefer to use Acetoacetic acid in preference to glucose to generate ATP.

Cortex of kidneys, Heart and muscles use Acetoacetic acid in preference to glucose to produce ATP.

Cortisol is the main Glucocorticoid Hormone which stimulates the breakdown of ______ into ________ to expand the pool of amino acids available for ___________. ______ from your pancreas stimulates the process to end.

Cortisol is the main Glucocorticoid Hormone which stimulates the breakdown of proteins into amino acids to expand the pool of amino acids available for gluconeogenesis. Glucagon from your pancreas stimulates the process to end.

Protein Anabolism (Synthesis)

Creates new proteins by bonding together amino acids on Ribosomes.

Digested Proteins are broken down into ___ ___ which are not stored, but are either oxidized to produce ______ or used to synthesize protein.

Digested proteins are broken down into amino acids, which are not stored, but are either oxidized to produce ATP or used to synthesize protein.

Protein Synthesis is stimulated by _________?

Directed by cells DNA & RNA, Insulinlike growth factor, TH, Insulin, estrogen & testosterone to stimulate protein synthesis.

Glycolysis

During Cellular Respiration this occurs in Cytosol. Converting Glucose into Pyruvic acid. It is a process whereby a 6-carbon glucose molecule is split into two 3-carbon molecules of pyruvic acid; and involves 10 reactions.

Glycerol

During Gluconeogenesis, may be converted into glyceraldehyde 3-phosphate which may form pyruvic acid or be used to synthesize glucose. Also Thyroid hormones TSH3 TSH4 mobilize proteins and may mobilize triglycerides from adipose tissue making glycerol available for gluconeogenesis.

Cellular Respiration

During Glucose Catabolism, Oxidation of glucose to produce ATP involves a set of four reactions: 1. Glycolysis- can occur under Aerobic & Anaerobic conditions. 2. Formation of Acetyl Coenzyme A 3. Krebs Cycle Reactions- occur only Aerobic conditions 4. Electron Transport Chain Reactions- occur only Aerobic conditions.

During Fasting and starvation the body makes metabolic changes to survive. The most dramatic change that occurs is the increase production of _______ as catabolism of fatty acids increases.

During fasting and starvation the body makes metabolic changes to survive. The most dramatic change that occurs is the increase production of Ketone bodies as catabolism of fatty acids increases.

During post absorptive state ______ needs are met by fuels already in the body.

During post absorptive state energy needs are met by fuels already in the body.

During absorptive state glucose is _______ available.

During the absorptive state glucose is readily available.

Epinephrine & Norepinephrine enhance ________ ________? The hormones are released during sympathetic tone increases, such as when we exercise.

Epinephrine & Norepinephrine enhance triglyceride breakdown during Lipolysis. The hormones are released during sympathetic tone increases, such as when we exercise.

Excess Carbohydrates can be turned into _______ which can be stored as fat.

Excess Carbohydrates can be turned into triglycerides which can be stored as fat.

Excess dietary carbohydrates, proteins, and fats are converted into?

Excess dietary carbohydrates, proteins, and fats are converted into triglycerides.

Fasting is going without food for several _____ or a _____ days.

Fasting is going without food for several hours or a few days.

Glucose 6-Phosphate is involved in?

Glucose 6-Phosphate is involved in - Synthesis of Glycogen -Release of glucose into the bloodstream -Synthesis of nucleic acids (RNA & DNA) -Glycolysis

Glucose 6-Phosphate is needed for the synthesis of Nucleic Acids which is important to form?

Glucose 6-Phosphate is needed for the synthesis of nucleic acids which is important to synthesize RNA & DNA

Glycerol & fatty acids can under go Anabolic reactions to produce other lipids such as _____ _____ _____.

Glycerol & fatty acids can under go Anabolic reactions to produce other lipids such as, Lipoproteins, phospholipids and cholesterol are lipids.

Hepatocytes contain _______ enzymes allowing glucose derived by glycogen to enter the blood stream via transport GluT. While Skeletal muscle cells break down glycogen into _______ which is catabolized for ATP production.

Hepatocytes contain phosphatase enzyme allowing glucose derived by glycogen to enter the blood stream via transport GluT. While skeletal muscle cells break down glycogen into glucose 1-phosphlate which is catabolized for ATP production.

Release of glucose into blood stream is main done by which cell?

Hepatocytes release glucose into blood stream mainly.

Reduction

Involves the addiction of electrons to a molecule. Example: pyruvic acid to lactic acid.

Oxidation

Involves the removal of electrons from an atom or molecule. Example: lactic acid into pyruvic acid.

Glucagon

Is activated to reverse Glycogenesis & is stimulated by epinephrine from adrenal medullae and is formed from pancreatic Alpha cells.

ATP Synthase

Is an enzyme with H+ channels that synthesizes ATP inside the inner mitochondrial membrane, which carriers are clustered into three complexes, each acting as a proton pump that expels H+.

Glycogenolysis

Is the process of ATP being needed for body activities; and Glycogen is broken down, & split up into subunits turning it into glucose to be released into the bloodstream.

Lactic Acid produced by Glycolysis in muscle cells can be converted into Glucose in the liver and deliver to the blood stream by ____________.

Lactic Acid produced by Glycolysis in muscle cells can be converted into Glucose in the liver and delivered to blood stream via Hepatocytes.

Name some Incomplete Proteins that do not have all essential amino acids?

Leafy green vegetables, legumes (beans & peas) & grains.

The arcuate nucleus and paraventricular nucleus of the hypothalamus are the areas that control hunger. Which hormone helps o decrease adiposity (body fat mass)? What stimulates food intake? What inhibits food intake?

Leptin is a hormone that helps decrease adiposity (body fat mass) and is released by adipocytes and inhibits Neuropeptide to decrease food intake. Neuropeptide Y stimulates food intake. Melanocrotin inhibits foo intake.

Lipolysis is catabolized by the enzyme _________?

Lipolysis is catabolized by the enzyme Lipases.

Hepatocytes

Located within the Liver. They convert most of the remaining fructose and practically all of the galactose to glucose.

Low-Density Lipoproteins (LDLs) can be elevated with increased ______ and may have a higher risk for _______. Cholesterol is deposited _____ and _______ forming fatty ______.

Low-Density Lipoproteins (LDLs) can be elevated with increased cholesterol and my have a higher risk for CAD. Cholesterol is deposited in smooth muscle fibers and arteries forming fatty plaque.

When proteins work as enzymes, what functions do they take on?

Many proteins functions as enzymes, and are involved in transportation, serving as antibodies, clotting blood (fibrinogen), being hormones (insulin), or serve as contractile elements in muscle fibers (actin and myosin).

Lipids

May be oxidized to produce ATP. When the body does not need lipids, they store it within Adipose tissue through out the body and Liver. Some are used as structural molecules and others to synthesize other essential substances. Lipoproteins for transport of cholesterol, Thromboplastin Blood clotting and myelin stealth to speed up nerve impulses.

How do you measure metabolic rate in the body?

Metabolic rate is measured with the body in a quiet, resting and fasting state called Basal metabolic rate (BMR).

Metabolic rate is the overall rate at which metabolic reactions use ______.

Metabolic rate is the overall rate at which metabolic reactions use energy.

Glucose 6-Phosphate, Pyruvic Acid and Acetyl Coenzyme

Metabolisms three important molecules.

Facilitated Diffusion Via GluT and GluT4

Molecules that transport Glucose into the plasma membrane and enter the cytosol. A high level of Insulin increases the insertion; and facilitates diffusion of glucose into the cell. Once inside the cell GluT can no longer transport glucose as it becomes phosphorylated glucose; and this reaction traps glucose within the cell.

Most Glucose is _________ to generate ATP. However, _______ reaction happens during Glycogen synthesis of new glucose molecules during protein & lipid breakdown.

Most Glucose is Catabolized to generate ATP, However, Anabolic reactions occurs during Glycogen synthesis of new glucose molecules during protein lipid breakdown.

Most fuel molecules that will be oxidized for generating ATP, Glucose, fatty acids and Ketone bodies are 1st converted into _____?

Most fuel molecules that will be oxidized for generating ATP, Glucose, fatty acids, and Ketone bodies are 1st converted into Acetyl coenzyme A.

Coenzymes

Nicotinamide adenine dinucleotide (NAD) and Flavin adenine dinucleotide (FAD) transfer liberated hydrogen atoms from substances that have been oxidized, to another compound. Oxidized NAD+, Reduced NADH + H+ and Oxidized FAD, Reduced FADH2

Physical activity improves aerobic levels raises ______levels and reduces risk of CAD.

Physical activity improves aerobic levels raises HDL levels and reduces risk of CAD.

Exergonic

Produce more energy than they consume, releasing the chemical energy stored in organic molecules ,used to form ATP.

The main component of most cells is?

Protein is the main component of most cell structures and is essential during growth years, pregnancy & when tissue has been damaged by disease or injury.

Protein synthesis occurs when these two groups of amino acids are present in a cell?

Protein synthesis occurs when both essential and non essential amino acids are present in a cell.

Aerobic Respiration

Reactions of Krebs cycle and Electron transport chain require oxygen.

Catabolism

Reactions that break down complex molecules into simpler ones. (decomposition) and are exergonic.

Anabolism

Reactions that combine simple molecules to make complex molecules. (synthesis) and are endergonic.

Metabolism

Refers to all of the chemical reactions taking place in the body. Results from the balance of anabolic and catabolic reactions.

Regulation of metabolism depends on chemicals in the cells and signals from _____ and _____ systems.

Regulation of metabolism depends on chemical in the cells and signals from nervous and endocrine systems.

Anaerobic Glycolysis

Result when Glycolysis occurs by itself under anaerobic conditions.

Electron Transport Chain

Series of Electron carriers, within Mitochondrial membrane. Each carrier in the chain is reduced as it picks up electrons and oxidized as it gives up electrons. This is an Exergonic reaction that releases small amounts of energy; used to form ATP. During Cellular Respiration, the final electron acceptor of the chain is oxygen. And involves Chemiosmosis a mechanism linking chemical reaction with the pumping of hydrogen ions.

ATP Formation

Some energy is released during oxidation reactions; and is captured when ATP is formed. A phosphate group is added to ADP (phosphorylation) along with energy to form ATP.

Starvation is going without food or inadequate food intake for ______ or _______.

Starvation is going without food or inadequate food intake for weeks or months.

Statins are used to block the key enzyme ______ needed for cholesterol synthesis.

Statins are used to block the key enzyme HMG-CoA Reductase needed for cholesterol synthesis.

Glycogen

Stored glucose within skeletal muscle and Hepatocytes. When ATP is needed another process breaks down glycogen into glucose and is released to the bloodstream directly by Hepatocytes. Lactic acid produced by muscle cells during glycolysis can be converted to glucose in the liver and Muscle glycogen can be an indirect source of blood glucose.

Where does synthesis and breakdown of glycogen occur mainly?

Synthesis and break down of glycogen occur mainly in skeletal muscle fibers and Hepatocytes.

Protein Catabolism (Breaking down)

Takes amino acids which Hepatocytes convert to other amino acids, fatty acids, ketone bodies or glucose. Process stimulated by Cortisol from adrenal cortex from proteins from worn out cells of RBC's broken down into amino acids & can be resynthesized and recycled.

Glucose

The bodies preferred source for synthesizing ATP.

Carbohydrate Metabolism (Glucose Metabolism)

The bodies use of glucose depends on the needs of the cells. -ATP production-immediate energy glucose is oxidized to produce ATP. -Amino acid synthesis- Use of glucose to form amino acids & can be incorporated into protein. -Glycogen synthesis-Hepatocytes & muscle fibers perform glycogenesis -Triglyceride synthesis-Lipogenesis

ATP (adenosine trisphosphate)

The molecule that participates most often in energy exchanges in a living cell, which couples energy-releasing catabolic reactions to energy-requiring anabolic reactions.

Where is our natural body's thermostat located? Which receptors send signals depending on our body's needs? Which feedback mechanisms controls this?

The preoptic area of the hypothalamus is the body's thermostat. Thermoreceptors send information to the preoptic area which sends signals to the heat-losing center and heat-promoting center of the hypothalamus, depending on the body's needs. Negative feedback mechanisms conserve heat and increase heat production.

Glycogenesis

The process of creating Glycogen to store glucose not needed immediately is stimulated by the hormone Insulin from pancreatic beta cells to have hepatocytes and skeletal muscle cells to convert glucose into glycogen.

Lipolysis (Lipid Catabolism)

The process of splitting triglycerides into fatty acids and glycerol, in order for muscle, liver and adipose tissue to oxidize fatty acids derived from triglycerides to produce ATP.

Lipogenesis (Lipid Anabolism)

The process of synthesizing lipids from glucose or amino acids, and occurs when we consume more calories then needed.

The rate of metabolic reactions control the amount of heat produced by the body. The rate of heat ____ must equal the rate of heat _____ to maintain homeostasis of body temperature.

The rate of metabolic reactions control the amount of heat produced by the body. The rate of heat loss must equal the rate of heat production to maintain homeostasis of body temperature.

Gluconeogenesis is stimulated by ________ ________ _____hormones.

Thyroid, Glucagon from pancreas, Cortisol Adrenal Cortex hormones stimulates this process. When body runs out of glycogen, the body begins to catabolize. This is the process by which glucose is formed from noncarbohydrate sources and forms glucose from proteins & fats (amino acids, lactic acid and glycerol).

Oxidative entry into Krebs Cycle occurs?

When Acetyl COA converts to Co2 & produces reduced coenzymes NADH & FADH2 which transfer electrons into Electron Transport Chain and in return generate ATP.

Mitochondria

Where reactions of Cellular Respiration occur producing ATP. Exception Glycolysis which occurs in Cytosol.

Intestinal Epithelial Cells

Where some fructose is converted into glucose as it is absorbed within the intestine.

Aerobic Conditions

With oxygen. All steps of cellular respiration occur. Glycolysis, Pyruvic acid converts to Acetyl Coenzyme A, Krebs Cycle, and Electron Transport Chain Reactions. This allows for ATP production.

Anaerobic Conditions

Without oxygen. Example: Pyruvic acid converts to Lactic acid, which is sent out through the blood stream & is taken up by Hepatocytes of the liver where it is converted back to Pyruvic acid. The remainder of cellular respiration steps do not occur.