EXAM2 Flashcards

Question

Protein | Substrate

Answer 1

Pepsin | Enzyme

Answer 2

Thermic effect of food

Answer 3

It decreases digestible energy of food consumed.

Answer 4

5400 ## Footnote Males: EER = 662 - (9.53 x age[y]) + PA x [(15.91 x wt[kg]) + (539.6 x ht[m])] Females: EER= 354 - (6.91 x age[y]) + PA x [(9.36 x wt[kg]) + (726 x ht[m])]

Answer 5

The prevalence of diabetes is much higher in women than in men of normal weight (based on BMI).

Answer 6

Indirect calorimetry

Answer 7

* increasing lipogenesis in the adipose tissue. * increasing glucose uptake in the muscle and adipose tissue. * increasing glycogenesis in the liver

Answer 8

lipogensis

Answer 9

* It is highly active after a low-carb breakfast of bacon, eggs, and sausages. * 8 acetyl CoA are produced from a 16-carbon fatty acid. * The process requires NAD+ and FAD. * The process generates reducing quivalents.

Answer 10

* Glucose * Acetyl CoA * Amino acids * Ethanol

Answer 11

requires energy

Answer 12

a molecule of glucose is coverted to 2 molecules of pyruvate

Answer 13

increase energy expenditure

Answer 14

is stimulated by insulin

Answer 15

Saliva Mucus Amylase (Breaks alpha-1,4 glycosidic bonds in starches): Mastication

Answer 16

Muscular organ Gastric secretions (HCl) cause acidification of the meal * Denatures proteins Pepsin secretion * Unique protease that functions at low pH * Begins to break up peptide bonds Gastric lipase * Can start hydrolyzing fatty acids Intrinsic factor (this will come up later) * Vitamin B-12 absorption Muscle contractions grind and mix food to produce chyme Gastric emptying Protease anzymes

Answer 17

Produces bile acids that are stored in the gallbladder Central hub

Answer 18

Reflex initiated by the voluntary move of food from the mouth to the pharynx This reflex closes the epiglottis over the larynx This closes the trachea and allows food to move into the esophagus

Answer 19

Controlled by upper esophageal sphincter (UES) Travel via peristalsis Lower esophageal sphincter (LES): closes the distal end of the esophagus and blocks the reflux of stomach contents back into the esophagus

Answer 20

Muscle layers Blood supply Lumen (inside) Receives digestive enzymes and bicarbonate from the exocrine pancreas Receives bile acids from the liver via the gallbladder

Answer 21

Rich blood supply Lined with a single layer of epithelial cells (columnar) Highly pleated * Increased surface area due to villi and microvilli

Answer 22

* Do not project out into the lumen * Stem cells that replenish epithelial cell lining are down at the bottom of the crypt

Answer 23

majority; digestion/absorption

Answer 24

secrete mucin

Answer 25

hormone secretion

Answer 26

immune monitoring

Answer 27

* Beginning to form fecal material * Large population of bacteria * These digest dietary fiber and can produce short chain fatty acids that can be absorbed into the bloodstream * Where water and some minerals are absorbed

Answer 28

stores and expels feces via the anus

Answer 29

Autonomic nervous system: regulates function of visceral organs

Answer 30

* Small polypeptides released from GI tract into the blood in response to meal * Secretion of: Digestive enzymes, mucus, water, bicarbonate, HCl, bile acids * Regulated to maintain homeostasis * Example: bicarbonate to deal with acid in the small intestine * Cholecystokinin, secretin, gastrin, gastric inhibitory peptide

Answer 31

Sweeping motion that propels food forward (swallowing) * Stomach and small sections of small intestine

Answer 32

Closely spaced contractions in discrete areas of the INTESTINE that act to mix the chyme with the digestive secretions and increase contact with the mucosal surface * Primary motive

Answer 33

Contractions that occur over a large area of INTESTINE that act to move the waste towards the rectum

Answer 34

Lower esophageal sphincter is loose Stomach contents reflux back up into the esophagus The acidic content irritates the lower esophagus Distinct from heartburn (which is an occasional experience of this) Drugs to combat this: * Neutralize acid (antacid) * Block acid secretion * Proton pump inhibitor

Answer 35

Salivary amylase – begins to break down alpha-1,4 glycosidic bonds from amylose and amylopectin * Does not break alpha-1,6 bonds Most carbohydrate digestion occurs in the small intestine * Also uses amylase from the pancreas Amylase converts amylose and amylopectin into dextrins * Small pieces of starch polymers containing alpha-1,4 and alpha1,6 Dextrins are further broken down by the brush border enzymes

Answer 36

Organization of SI microvilli on enterocytes that we discussed previously looks like a fuzzy layer on a light microscope, hence the term The microvilli membrane is studded with glycosidases that break down the dextrin

Answer 37

Lactose is disaccharide Do not produce lactase Observed more frequently in individuals of Asian, African, or Mediterranean origin

Answer 38

Glucose and galactose are actively transported by the Na+ dependent transport protein (SGLT1) * Goes “uphill” against their concentration gradients using energy Fructose is transported by a separate GLUT5 transporter * “Facilitated” transport – moves with the concentration gradient * Protein channel without energy input GLUT2 transporter * Basal transporter that moves glucose, galactose, and fructose out of the cell and into the blood. Moves with the concentration gradient

Answer 39

Stomach is where this largely starts * Stomach acid (HCl) denatures proteins Pepsin is released * Unique protease that is active at low pH As with carbohydrates, small intestine is where the majority of protein digestion and amino acid absorption occur * Pancreas secretes digestive enzymes and bicarbonate into the small intestine * The proteolytic enzymes are released from the pancreas as inactive proenzymes and are later activated in the small intestine * These enzymes hydrolyze peptide bonds producing oligopeptides Amino acid absorption * Brush border peptidases hydrolyze oligopeptides into di- and tripeptides and individual amino acids * These are then transported across the intestinal cell membrane by brush border transporters * Active and facilitated transport * Transporters then move the amino acids and small peptides out of the basal region of the cell and into the blood

Answer 40

Largely starts in the stomach * Production of gastric lipase: hydrolyzes TG to FFA and monoglycerides Pancreatic lipase acts together with the protein co-lipase to hydrolyze TGs Small intestine is the major site Gallbladder stores and releases bile acids and lecithins which emulsify giving the co-lipase and lipase enzymes access to the TGs. * End products are FFA, monoglycerides, and glycerol Micelles form from monoglycerides and FFA surrounded by bile acids * Gives the lipids access to the epithelial cells (and is needed for lipid soluble vitamin absorption) Absorption of FFA, monoglycerides, and glycerol is by diffusion and protein mediated transport Bile acids: produced in liver, released from the gallbladder, and most are reabsorbed (~98%) in the terminal ileum and travel in the blood back to the liver (enterohepatic circulation – via the hepatic portal vein)

Answer 41

Energy density unit: kcal/g Nutrient density unity: mg/kcal * Amount of micronutrients and protein of a food item relative to its energy content

Answer 42

Simple sugars and starches are broken down in our digestive tract and absorbed as monosaccharides Travel to liver, where it is converted to glucose Possible uses: * Metabolism * Store as glycogen * Convert to fat for storage * Distribute to rest of body Muscle can use for energy or store as glycogen

Answer 43

Triglycerides are broken down and absorbed as fatty acids, then packaged as lipoproteins and processed through the liver A series of lipoproteins are used to deliver triglycerides to other organs, where the fatty acids can be burned. Some tissues also store fats, notably adipose tissue that is your primary fat reserve

Answer 44

Broken down during digestion and absorbed as single amino acids (mostly) Also get processed through the liver for distribution or metabolism Generally, we don’t use amino acids for energy, although the carbon skeleton can be used to make pyruvate or acetyl-CoA

Answer 45

Carbs: 4kcal/g Fats: 9kcal/g Protein: 4kcal/g

Answer 46

Bomb calorimeter measures gross energy of food Vitamins contribute to gross energy of food but don't have metabolizable energy content because the human body can’t oxidize Minerals don’t have gross energy

Answer 47

Primarily stored as adipose tissue triglyceride Fill muscle triglycerides, muscle glycogen, liver triglycerides, and liver glycogen with positive energy before being stored as fat

Answer 48

Increases difference between gross energy and digestible energy of foods containing fat. Thereby decreasing caloric intake Digestible energy of all food containing fat decreases Fat excreted in feces causing discomfort

Answer 49

Digestible and metabolizable energy decrease Type of fat body isn’t able to absorb Added to foods with fats without changing taste Fat excreted in feces causing discomfort

Answer 50

Accessibility Geographical Socioeconomic Culture Family Climate

Answer 51

Hunger, satiation, appetite, satiety

Answer 52

a physiological response to nerve signals and hormones after a lack of sufficient food

Answer 53

a sensation that prompts the cessation of eating during a meal

Answer 54

the desire to eat

Answer 55

the feeling of fullness and satisfaction that persists after a meal

Answer 56

hunger hormone comes from the stomach acting on hypothalamus

Answer 57

stimulation of pancreatic secretion and gallbladder contraction (releasing bile to digest fats) * Also, a satiation signal and then a satiety signal * Peptide hormone

Answer 58

has many functions including the stimulation of insulin secretion independent of blood glucose levels (this is called the **incretin effect**), also slows down gi tract, and provides yet another satiation and satiety signal. * Peptide hormone * Ozempic mimics this hormone by agonizing its receptor

Answer 59

Peptide protein hormone synthesized in adipose tissue which is a satiety signal * More adipose tissue, more leptin made

Answer 60

Share circulation and hormones used to figure out much of what we know about leptin * Leptin is a peptide secreted by the adipose tissue * Leptin transmits a signal through cell-surface leptin receptors on certain neurons in the hypothalamus

Answer 61

Mutation in gene that encodes leptin (Lepob) Respond but can’t produce leptin * Leptin mutation and are leptin deficient No functional leptin ## Footnote When combined with control +/+ there was no change in lean control but ob/ob obese had decreased food intake, insulinemia, and blood sugar

Answer 62

Mutation in gene responsible for encoding leptin receptor (Leprdb) Can produce leptin but can’t respond to it * Leptin receptor mutation, but produce leptin No functional leptin | +/+: Wildtype mouse control ## Footnote When combined with control or ob/ob: increased body weight and adipose, decreased food intake, insulinemia, and blood sugar. Death by starvation. Control was lean and ob/ob obese

Answer 63

The amount of energy expended the digestion of food usually through heat production * Protein high leading to “Meat sweats”

Answer 64

core body temperature must resist change

Answer 65

storage and “browning” during cold to increase thermogenic capacity

Answer 66

mitochondria, non-shivering thermogenesis

Answer 67

non-shivering thermogenesis

Answer 68

* Energy expenditure measured by gas exchange method is the most accurate * Fat takes more O2 to oxidize than other macronutrients and produces more CO2

Answer 69

* Only works for those at or above age 19 * Increase in age will decrease energy expenditure * Formula different for men and women * Greater energy expenditure for men due to weight difference * Muscle vs fat result in different expenditures which aren’t accounted for in the formula

Answer 70

use accelerometer and HR (20-90% error margin)

Answer 71

Weight (kg)/ Height² (m²) Distribution of adipose tissue matters

Answer 72

Estimate body fat using caliper to gauge thickness of fold of skin on arm and below shoulder blade, then compare to standards

Answer 73

Weight person on land and then submerged in water. Difference provides measure of body's volume. Equation for volume and weight calculates body density and percentage of body fat

Answer 74

estimates body composition by having person sit inside chamber while computerized sensors determine the amount of air displaced by body

Answer 75

measures body fat with low-intensity electric current. Electrolyte-containing fluids, which conduct current, are found in lean body tissues, therefore, a leaner person will have less resistance to current

Answer 76

measures central obesity by placing nonstretchable measuring tape around wait

Answer 77

low-dose x-rays differentiate among fat-free soft tissue (lean body mass), fat tissue, and bone tissue, providing total fat and distribution

Answer 78

Concentration of insulin higher than glucagon, favoring energy storage Blood glucose elevated Glycogen storage increases Glucose is the main energy source RBC need because no mitochondria to oxidize fatty and amino acids Amino acids are used for protein synthesis Excess amino acids are converted into fatty acids Transitory positive energy balance when nutrients not used immediately

Answer 79

Insulin from pancreas levels decrease and glucagon increases Blood glucose decrease Increased liver glycogen broken down for glucose Increase use of fatty acids for energy Glycogen and fatty acids mobilized Dietary fatty acids are converted to body fat

Answer 80

Concentration of glucagon higher than insulin Liver glycogen stores depleated Glucose mainly from gluconeogenesis Stored TGs broken down and fatty acids used for energy Ketogenesis (ketone formation) increases First five days of fasting, beginning 24 hours after the last meal

Answer 81

Food deprivation for an extended period of time, typically longer than one week Reduced metabolism Only red blood cells rely solely on glucose as a substrate for ATP production Ketones are major energy source Fat is limited; muscle and vital organ breakdown continues until death

Answer 82

As glycogen stores dwindle, the body begins to break down its protein (muscle and lean tissue) to amino acids to synthesize glucose needed for brain and nervous system. In edition, the liver converts fats to ketone bodies, which serve as an alternative energy source for the brain, thus slowing the breakdown of body protein

Answer 83

* Providing substrates * Modulating activities of various enzymes * Precursors for coenzymes/cofactors for metabolic reactions * Regulate secreting of hormones * Interactions with gut microbiome

Answer 84

* Promote glucose uptakes in certain tissues * Promote glucose use for glycogenesis and lipogenesis * Promote anabolism in general (eg. protein synthesis, which requires energy) * Suppress gluconeogenesis * Suppress ketogenesis * Suppress lipolysis, limiting fuels for beta-oxidation

Answer 85

Diabetes is a medical condition characterized by elevated blood glucose levels (Hyperglycemia) due to a lack of insulin or impaired responses to insulin (i.e. “Insulin resistance”)

Answer 86

Less common type Autoimmune disorder Pancreas loses ability to synthesize insulin Commonly occurs in childhood & adolescence Energy metabolism changes May threaten survival Need insulin injections or external pump

Answer 87

Most prevalent form of diabetes Exact cause is unknown Risk factors Insulin resistance Hyperinsulinemia: high level of insulin in blood Amount of insulin is insufficient to compensate for diminished effect in cells Chronic inflammation

Answer 88

Type I diabetes requires insulin injections * Multiple injections required daily * Pumps make diabetes easier to manage Diabetes is chronic, progressive disease * Requires lifelong treatment * Management involves balancing meal planning, timing of medications, physical exercise Primary goals * Establish good glycemic control * Reduce incidence of complications Diabetes education major need for newly diagnosed patients & families

Answer 89

a measure to foods based on how slowly or how quickly those foods cause increases in blood glucose levels, often reflecting how quickly carbohydrate in a food is digested and absorbed. Foods high on the glycemic index release glucose rapidly. * Low GI foods tend to foster weight loss, while foods high on the GI scale help with energy recovery after exercise, or to offset hypo- (or insufficient) glycemia. * Long-distance runners would tend to favor foods high on the glycemic index, while people with pre- or full-blown diabetes would need to concentrate on low GI foods.

Answer 90

toxic and can cause blindness, kidney failure, or increase cardiovascular risk

Answer 91

Dietary factors Quantity of foods Quality of foods * GI and GL * Whole vs processed * CHO types * Fat and protein * Fibers Timing * Circadian rhythm

Answer 92

* Digestion/absorption * Insulin sensitivity * Insulin secretion * Physical activity * Lean body mass * Previous meal * Gut microbiome

Answer 93

the sum of life-sustaining reactions which convert nutrients to energy driving cellular processes, to building blocks for cellular components, and to wastes for excretion

Answer 94

chemical reactions involved in breakdown, synthesis, and transformation of energy-yielding nutrients that enable cells to obtain and use energy from nutrients

Answer 95

Breaking down energy yielding macronutrients Consume oxygen, generate ATP, CO2, and H2O Activities are determined by demands and available substrates

Answer 96

Glycogenesis Lipogenesis Depends on substrate availability and stimulated by insulin

Answer 97

Gluconeogenesis Ketogenesis Suppressed by insulin (stimulated by glucagon, adrenaline, etc.)

Answer 98

Toxic levels of phenylalanine (amino acid), due to inability of the body to convert. Mutation in the enzyme that converts phenylalanine to tyrosine Tyrosine would be considered a conditional essential amino acid

Answer 99

Catalysts and regulators of metabolic processes Classified by type of chemial reaction they catalyze Enzymes are not consumed in the process

Answer 100

regulatory nutrients (vitamins and minerals) Coenzymes are often required during oxidation of energy-yielding nutrients Energy metabolism involves series of oxidation/reducing reactions Electron transfer in redox reactions * NAD+: a coenzyme coupling redox reactions * Intermediate carrier of hydrogens * Oxidized: gain oxygen or loses hydrogen * Reduced: loses oxygen or gains hydrogen

Answer 101

By “oxidizing” the carbons macro-nutrients contain, catabolic processes break these organic nutrients and release the biochemical energy and capture the energy as ATP. The overall processes consume oxygen as the electron acceptor and produce carbon dioxide.

Answer 102

* Stage 1: Breakdown of complex molecules to building blocks * Stage 2: Conversion to intermediates that can enter citric acid cycle and produces “reducing equivalents” (reduced form of the coenzymes; NADH + H+ and FADH2) * Stage 3: Citric acid cycle breaks intermediates down to carbon dioxide and produces “reducing equivalents” ** Substrate-level phosphorylation produces small amounts of ATP * Stage 4: Electron transport chain ** Using “reducing equivalents” ** Produce ATP through oxidative phosphorylation

Answer 103

* Splitting 6C glucose and generating 2 3C pyruvates * It requires energy investment, takes two ATPs to start the process. * Generates reducing equivalents (reduced coenzymes that carry H with its electron to ETC for producing more ATPs) * Some cells, such as RBC only have this pathway to generate the ATPs needed to maintain the Na pumps and the NADH to convert Fe3+ in the ferri-hemoglobin back to the functional Fe2+ in hemoglobin.

Answer 104

* Occurs in cytoplasm * Regenerates glucose by circulating lactate from muscle to liver, where it undergoes gluconeogenesis * Provides small amounts of ATP that can be produced in muscle in the absence of O2 * Regenerates NAD+ for glycolysis * Aerobic conditions: the irreversible conversion of pyruvate to Acetyl CoA * Under normal condition, the 3-carbon pyruvate will undergo an irreversible conversion to the 2 carbon-acetyl CoA. The process generates more reducing equivalent NADH and require other B-vitamins (vitamin B 1 and vitamin B5).

Answer 105

Breaking down fat (triacylglycerol) To breakdown fat, the Stage 1 reaction is lipolysis to release fatty acids from glycerol. The 3-carbon glycerol enter part of the glycolysis pathway, while majority of the carbons in fatty acids undergo beta-oxidation to generate abundant acetyl CoAs and reducing equivalents.

Answer 106

Beta-oxidation takes place in the matrix mitochondria. The substrates, fatty acids need to pass two sets of membranes.

Answer 107

To enter mitochondria, long chain fatty acids (most dietary fatty acids) need the help of another B vitamin-like compound, carnitine. During each round of beta-oxidation, the beta-carbon of fatty acyl group is cleaved off, generating one molecule of acetyl CoA and a pair of reducing equivalents, NADH (derived from vitamin B3) and FADH2 (derived from Vitamin B2). 1. The fatty acid is activated by the addition of coenzyme A to its carboxylic acid end. The fatty acid is then transported across the mitochondrial membrane by a molecule called carnitine 2. The process of b-oxidation involves enzymes that cleave off 2-carbon units from the fatty acid chain, forming acetyl-CoA. This process repeats itself until the entire fatty acid has been broken down. Each cleavage generates 1 NADH + H+ and FADH2. 3. b-oxidation of an 18-carbon fatty acid generates (8) NADH + H+ and (8) FADH2. 4. A total of 40 ATP are subsequently produced via the electron transport chain.

Answer 108

To breakdown proteins, the Stage 1 reaction is proteolysis, while the Stage 2 is more complicated as there are 20 different amino acids. A common step shared by all amino acids is that the nitrogen-containing amino group needs to be removed. GOT/AST: glutamic oxaloacetic transaminase or Aspartate transaminase GPT/ALT: Glutamic-Pyruvic transaminase or Alanine transaminase (aminotransferase) Most amino acids are glucogenic and can be used to synthesize glucose * Some amino acids are converted directly to acetyl CoA, they are ketogenic * Some amino acids can enter the TCA cycle directly, they are glucogenic

Answer 109

The amino group can be removed by transamination, which transfer the amino group to another keto acids to generate non-essential amino acids or other nitrogen-containing compounds. Alternatively, excess amino groups can be removed by deamination to generate ammonia. Transamination and synthesis of nonessential amino acids Transaminases in the liver Deamination of an amino acids produces ammonia and a keto acid

Answer 110

Urea excretion: liver and kidneys dispose excess nitrogen. Liver disease causes high blood ammonia and kidney disease causes high blood urea Kidney failure: too much blood in urea

Answer 111

Although alcohol is not considered a nutrient, it does provide energy. Alcohol is absorbed directly into circulation and liver often metabolizes it first to reduce its potential toxicity. The process involves two oxidation steps to generate reducing equivalents and acetyl CoA, just like other stage 2 reactions for glucose, fatty acids, and amino acids.

Answer 112

Carbon skeletons from amino acids enter energy-yielding catabolic pathway via various points of TCA cycle Need acetylacetonate The TCA or citric acid cycle is the Stage 3 pathway, which is shared by all energy-yielding nutrients. The cycle starts with the combination of acetyl CoA, the common end product of all Stage 2 pathways, with a 4-carbon oxaloacetate to generate the 6-carbon citric acids. Through a series of reactions, many reducing equivalents are generated and two carbons are released as carbon dioxides, resulting in a molecule of oxaloacetate to start the cycle again.

Answer 113

The electron transport chain is responsible for majority of the ATP production and the regeneration of oxidized co-enzymes. The reduced form of coenzymes or reducing equivalents deliver their electrons to a series of protein complexes that form the electron transport chain on the inner membrane of mitochondria, and the protons (H+) are pumped into the inter-membrane space, which creates a proton gradient needed to drive ATP production by the ATP synthase. Oxygen serves as the final electron acceptor and along with the proton is turned into the final product water (the other final product is CO2 released in the TCA cycle).

Answer 114

located on the inner mitochondrial membrane allows H+ ions to enter the mitochondrial matrix (bypassing ATP synthase). To generate same amount of ATP, overexpression or activation of UCP: require more O2

Answer 115

Short-term Regulation of metabolic processes * “Location and timing” Substrate availability * Enzyme activity (long-term Regulation of metabolic processes expression levels and post-translational modifications modulated by hormones) * Coenzyme availability ATP/ADP ratio * Coordinated by two major pancreatic hormones, insulin and glucagon. * Many other hormones may play a role as well.

Answer 116

High levels of ketones in blood Exhale in breath Excrete in urine

Answer 117

Severe ketosis Lower blood pH Results in nausea, coma, and death Often occurs in patients with uncontrolled type I diabetes

Answer 118

* Generates glycogen from glucose * Takes place in liver and muscle tissue * Stimulated by insulin * Limited storage ## Footnote Converts excess glucose into glycogen for storage in liver and muscle cells

Answer 119

* Forms fatty acids, using acetyl CoA, and triglycerides from glucose or amino acids * Takes place in liver and adipose tissue * Insulin promotes lipogenesis * Conversion of glucose to fatty acids is irreversible ## Footnote Converts excess glucose, proteins, and dietary fats into triglycerides for storage in adipose tissue as fat

Answer 120

cells use to breakdown complex storage molecules into simple energy substrates including glycogenolysis, lipolysis, and proteolysis; catabolic pathways that cells use to generate "reducing equivalents (NADH and FADH2, which carry electrons from the oxidation of energy-yielding nutrients to electron transport chain), including glycolysis, beta-oxidation, and the TCA cycle shared by all energy-yielding nutrients; and the final oxidative phosphorylation that generates ATP through the electron transport chain. Note that glycolysis also generates ATP.

Answer 121

I.e. amino acids, glycerol, and lactate Ensures glucose to tissues like brain and red blood cells during fasting when glycogen depleted and to maintain blood glucose Transforms noncarbohydrate molecules into glucose by various anabolic pathways Amino acids, lactate, glycerol Occurs primarily in liver and kidneys Provides glucose during starvation Stimulated by glucagon and cortisol Inhibited by insulin ## Footnote synthesis of glucose from non-carbohydrate sources

Answer 122

Alternative fuel during fasting and spares muscle protein breakdown Anabolic pathways used to produce ketones from mostly acetyl CoA and some ketogenic amino acids Triggered by excess acetyl CoA and low oxaloacetate levels Occurs mostly in the liver Inhibited by insulin Important energy source during starvation Spares amino acids ## Footnote produces ketone bodies in the liver from fatty acids

Answer 123

Gluconeogenesis and ketogenesis upregulated Glycogenolysis activated to release stored glucose, while lipolysis and proteolysis provide substrates for gluconeogenesis and ketogenesis

Answer 124

Insulin secreted by beta cells in endocrine pancreas, promoting glucose uptake, glycogenesis, and lipogenesis Inhibits gluconeogenesis and ketogenesis

Answer 125

Induces ketogenesis as metabolic pathway for energy, increasing ketone body production and utilization

Answer 126

Stimulates glycolysis for glucose metabolism, promotes glycogenesis for energy storage and suppresses ketogenesis

Answer 127

Metabolic Responses After a Ketogenic Diet Adult Consumes a Big Breakfast: * Hormone Secretion: Beta-cells in the pancreas release insulin in response to the increase in blood glucose levels from the meal. * Glucose Uptake: Cells, including hepatocytes, myocytes, and adipocytes, increase glucose uptake due to insulin signaling, promoting glycogen synthesis and lipogenesis. * Metabolic Pathways Activation/Inactivation: Hepatocytes: Glycogen synthesis is activated, while gluconeogenesis and ketogenesis are inhibited due to elevated insulin levels. Myocytes: Glycogen synthesis is stimulated for energy storage. Adipocytes: Lipogenesis is activated to store excess glucose as fat Factors Modulating Glycemic Responses: Dietary Factors: Composition of the meal (carbohydrate, fat, protein content), fiber content, cooking methods, and meal timing. Host Factors: Insulin sensitivity, pancreatic function, muscle mass, physical activity level, and gut microbiota composition. * Blunting Glycemic Responses in Insulin Resistant Individuals: Choose Low-Glycemic Index Foods: Foods with a lower glycemic index result in slower and steadier increases in blood glucose levels. Incorporate Fiber: High-fiber foods slow down digestion and absorption of carbohydrates, reducing postprandial glucose spikes. Regular Physical Activity: Exercise improves insulin sensitivity and glucose uptake by muscles, helping to lower blood glucose levels after meals. Healthy Fats and Proteins: Including healthy fats and lean proteins in meals can slow down the absorption of carbohydrates, preventing rapid spikes in blood glucose.

EXAM2 Flashcards

(157 cards)