ADVANCED NUTRITION EXAM 1: LECTURES 1-ALCOHOL

Carbs, fat, protein

What are the main macronutrient fuels that circulate in the bloodstream?

 80-90 mg/dl 5mM

Normal fasting blood glucose concentration

70 mg/dl 4mM

Prolonged fasting blood glucose concentration

60 mg/dl 3mM

Light headedness/blurry vision blood glucose concentration

<40mg/dl 2mM

Passing out blood glucose concentration

<20 mg/dl 1mM

Severe brain damage blood glucose concentration

>126 mg/dl

Would suspect diabetes if glucose concentrations are higher than this.

Type 1 Diabetes

Insulin depend (lack of insulin)

Type 2 Diabetes

Lower insulin resistance

Glucose

What is the only fuel usually avaliable to the brain?

When levels drop below 3mM (60mg/dl)

What is the blood glucose concentration level in which the brain will be unable to obtain sufficient glucose?

120-140 mg/dL (6-7mM)

What is the typical glucose level after you consume a meal?

90mg/dl

Within 1.5-2 hours after a meal, what should your glucose return to?

70mg/dl (3.5mM) or 60mg/dl (3mM) but no further

What is the typical glucose level especially when fasting longer than overnight?

Can be unstable in solution and would be unable to pass through cell membranes, thus they are synthesized and degraded within cells.

Why is ATP not considered a necessary foodstuff?

glucose, free fatty acids, ketone bodies, some amino acids, lactate, and ethanol (and glycerol)

What are the major flues in our body that are necessary?

Glycogen

Stored form of glucose

triglycerides

Stored form of fatty acids

Brain

This organ can use glucose, ketone bodies, & lactate

Fatty acids

What fuel is the brain unable to use?

skeletal muscle

This organ can use glucose (glycogen for local use), fatty acids, ketone bodies, perhaps triglycerides, some amino acids (branched chain amino acids)

Heart

This organ can use free fatty acids (the primary fuel), triglycerides, ketones, glucose and lactate

Liver

This organ can use amino acids (primarily in the fed state), free fatty acids (during starvation), lactate, glucose, ethanol, glycerol

intestine

This organ can use glucose, glutamate (from diet), and glutamine

red blood cells

This organ can use glucose and break it down into lactate (lack a mitochondria so cannot perform mitochondrial actions)

kidney

This organ can use glucose, free fatty acids, ketone bodies, lactate, glutamine

adipocytes

These cells use glucose, triglycerides

Lymphocytes

These cells use glucose and glutamine

Colonocytes

These cells use butyrate

Tumor

This cell uses large amounts of glucose (to lactate) and glutamine.

to provide a constant supply of glucose

What is the purpose of integrating tissue specific metabolism?

free fatty acids and ketones

What are some fuels that the brain can use in place of glucose?

Liver and Kidneys

What are the only tissues that can release glucose into circulation?

Skeletal Muscle

What organ can store glucose?

CO₂ (also lactate in the brain)

What can glucose and ketone bodies be converted as in the brain?

CO₂

What can skeletal muscle glucose, fatty acids, Ketone bodies, and branched chain amino acids be converted into?

 lactate, alanine

What else can Glucose be converted into? (skeletal muscle)

glutamine, alanine

What else can Branched Chain AAs be converted into? (skeletal muscle)

CO₂

What can heart glucose, lactate, fatty acids, ketone bodies, triglycerides (aka fatty acids), acetate be converted into?

glucose & urea

What can liver Amino acid convert into?

 ketones and TAGS

What can liver Fatty acids convert into?

Lactate and glucose (glycogen)

What can liver Glucose convert into?

Glucose

What can liver Lactate, glycerol convert into?

lactate and CO₂

What can Kidney Glucose convert into?

CO₂

What can Kidney Fatty acids, ketones convert into?

 glucose, ammonia (only glutamine), CO2 (only glutamine)

What can Kidney Lactate and glutamine convert into?

Lactate and Glycerol in Triglycerides

What can Adipose Tissue Glucose convert into?

Triglycerides

What can Adipose Tissue fatty acids convert into?

glycerol and Fatty acids

What can Adipose Tissue Triglycerides convert into?

 glutamine, alanine

What can Branched chain amino acids convert into?

• 30% oxidized in brain

• 20% oxidized in muscle

• 50% stored as glycogen

What is the fate of carbohydrates after a meal?

• 95% stored as Triglycerides in adipose tissue

What is the fate of fats after a meal?

• 30% protein synthesis, 10% oxidized in enterocytes, 15% BCAA oxidized in muscle, 45% oxidized in liver

What is the fate of protein after a meal?

• metabolized to acetate in liver

What is the fate of Alcohol after a meal?

• insoluble passes through soluble fermented to  short-chain fatty acids (scfa)

What is the fate of fiber after a meal?

Cellulose has beta-linkages, while starch has alpha linkages, which amylose cannot break down.

Why can the human body break down starch but not cellulose?

glucose

sugar name

Galactose

sugar name

 Fructose, sucrose, glucose, fructose, allulose/psicose (newest, often in keto stuff) galactose, maltose, lactose

Rank relative natural sweetness of the sugars (most to least sweet):

Sucralose (splenda), Saccharine, aspartame (nutrasweet), steviosides (stevia)

Rank relative artifical/manmade sweetness of the sugars (most to least sweet):

Fiber

Plant material that cant be digested by human/mammalian enzymes but can be degraded by bacterial enzymes in the large bowel (can vary depending on how it is measured and is not constant due to plants being at different ages)

NON-STARCH POLYSACCHARIDES (NSP))

Definition of fiber, with the exception of lignin.

Lignin

Minor part of the diet unless you eat a lot of wood and can usually be ignored

Insoluble fiber

results in faster transit times throughout the lower GI tract (colon) and it adds directly to bulkier stools. Don’t stay around long enough

Soluble fibers

can slow transit time in the upper GI tract (stomach) due to gel formation, etc. but they have no real effect on fecal bulk. Fermented by bacteria and are susceptible to degradation by colonic microbes

Ulcerative Colitis

related to either direct butyrate deficiency or impaired butyrate oxidation (indirect butyrate deficiency)

volatile fatty acids or short chain fatty acids

Interesting in the sense that most are absorbed and are further metabolized whereas some can be used for other processes

Butyrate, Acetate, Propionate

Name 3 different short chain fatty acids:

Butyrate

Only avaliable from colonic fermentation, this implies that a healthy fermentation producing this short chain fatty acid is required for the health of the colon.

Water holding capacity, cation exchange properties (capacity to bind cations such as metals and compounds such as bile acids), and just general binding and absorbtion properties.

What are the few effects of fiber that can be related to physical properties?

• Helps with constipation

• slow digestion and lowers blood sugar spike (Diabetes)

• lowers risk of colon cancer

• binds to bile salts and drains cholesterol out of body (Hypercholesterolemia)

• diverticular disease (stops the formation of pouches/sacs bulging out of the colon wall)

Name some benefits of fiber

Resistant Starch

Different physical forms of starch are digested at different rates and that some forms are so resistant to digestion that they enter the colon intact where they may be fermented in butyrate mostly. (not easily digested)

Rapidly digested starch.

Found in freshly cooked foods. Completely and rapidly digested in the small intestine.

Slowly digested starch.

Present in most raw cereals (grains). Slowly digested but most is digested in the small intestine.

Physically inaccessible

Type of resistant starch that is present in partially milled grains

Starch granules

Type of resistant starch that is present in raw potato and unripe banana

Retrograded starch

Type of resistant starch that is present in old cooked potato, corn flakes, day old bread

Starch Blockers

These were plant derived (natural) compounds available as pills that if taken with a high starch meal would prevent you from becoming obese.

Acarbose

an alpha-amylase inhibitor. It is used for diabetics and it does not completely inhibit starch digestion, rather it slows it down, i.e. it is digested and absorbed slower and this blunts the rise in blood glucose after a meal.

Probiotics

containing live “beneficial” bacteria that are consumed by mouth with the intention of setting up a healthy microbiota in the colon. (examples: yogurts, miso paste, kefir, and many fermented products such as kimchee.)

Prebiotics

Consumed with the deliberate intention of promoting “beneficial” (bifidobacteria) bacterial growth. (resistant starches/soluble fibers)

Obese mice were still fat while lean mice were still lean. When the two were put together, obese mice became leaner.

When obese and lean mice were put in a different cage, what noticeably happened in said cages? Same cage?

Obese mice had more firmicutes and less bacteroidetes.

What was the reason for obese mice on getting fatter?

firmicutes

bad, unhealthy microbiota

bacteroidetes

good, healthy microbiota

HMO

Human milk oligosaccharides → The first referring to glycans terminating in lactose, the latter meaning more complex glycoconjugates with other carbohydrate scaffolds. Not digestible by human enzymes and pass into the colon for fermentation (Less ear infections, less ulcers, less kidney disease, less infections, better immunity) also prebiotics

Galactose, Fructose, and Glucose

What are the three major sugars from digestible carbohydrates?

A-destrinases,  maltase, a-amylase along with a-destrinases turning a-dextrines & maltase turning maltose into glucose

What are the enzymes used in starches to help with digestion?

SGLT1

(irreversible) An active transport system that allows it to take up glucose against a concentration gradient. → works by taking in sodium (2 sodium per glucose) and glucose together and then uses the sodium/potassium exchanger (ATP linked) to get the sodium out of the cell (and into the circulation) and so the glucose is trapped inside the cell.

SGLT2,

Variant in the kidney that acts to reabsorb filtered glucose

GLUT 2

When glucose is trapped IN THE CELL, this means that the concentration in the enterocyte increases and will rise above that of the blood. When this happens glucose will flow out of the cell into the circulation via a facilitative transporter (can also transport galactose and fructose)

allow more glucose (and fructose) to enter the cell

When there is high lumen glucose, what will GLUT 2 do?

Diarrhea → electrolyte (NaCl) solution the child absorbs both faster than if given alone (water can be pulled in the body thanks to NaCl)

What is SLGT1 useful for treating?

GLUT transporters

belongs to a family of glucose transporters in the body which are very closely related and share extensive DNA sequence identity, especially in the membrane spanning regions. Most can transport many different sugars but their affinity for most is very low and sugars other then glucose, galactose, fructose are extremely rare in the body.

GLUT5

The only one that isn’t considered to be a glucose transporter and is a fructose transporter

GLUT 1

found just about everywhere, fetal tissues, kidney, liver, intestine, muscle - it is not highly regulated.

GLUT 3

basal transport, not considered very important, in many tissues, brain, kidney, fetal muscle

GLUT 8

Which may be responsible for 25% of glucose uptake by the liver.

GLUT 4

the important one! Found in muscle and adipose tissue, it responds to insulin. Present inside the cell in vesicles, but on stimulation with insulin the vesicles move to the cell membrane where they will stay and increase the number of transporters there. (responsible for clearing about 1/3-2/3 of the carbohydrate from the circulation after a meal.)

exercise/contraction

What can increase glucose uptake into muscles via movement of GLUT 4