6: Physiology of Nutrient Metabolism Flashcards
All physical and chemical reactions in the body that use or convert energy is called _______.
metabolism
In reference to the “gut” as a tube, what are the organs along the way? MESSLRA
mouth, esophagus, stomach, small intestine, large intestine (colon), rectum, anus
What are the 4 stages of the digestion process?
Ingestion, digestion, absorption, utilization
The actual eating by chewing where food is converted into food bolus (ball) and transported down the esophagus.
Ingestion
The stage where carbs, protein and fats are broken down where “churning and burning” occurs.
digestion
The movement of molecules across the lining of the small intestine into the blood stream describes _______.
absorption
The molecule of nutrient is transported to the appropriate location to be utilized or stored.
utilization
The ____ is considered to be outside of the body.
gut
__________ is the most critical step in the whole digestive process.
Absorption
Why can athletes take in and use carbohydrates much more efficiently than a sedentary individual?
Their cells have been “trained” to perform a certain activity more efficiently. Utilization.
When do nutrients cross the cell wall and get destroyed, remolded chemically or reused?
during utilization process
The large intestine is composed of _______, ______, _______
colon, cecum, rectum
The _____________ is responsible for water regulation of the feces.
large intestine
What is the “specialist” in digestive functions?
Liver
What does the liver do in regard to fats?
Produces substances that break them down
How does the liver maintain proper levels of glucose in the blood?
glycogenolysis (breaks down glycogen into glucose)
or
gluconeogenesis (Creates glucose from non-carbohydrate sources like lactate, glycerol, and amino acids)
Where does the conversion of glucose to glycogen take place?
Liver
The liver uses transamination of amino acids into _____ which produces ______
keto acids; urea
Does the liver make amino acids?
Certain ones, yes
Where does the filtering of certain harmful substances take place?
Liver
What vitamins does the Liver store?
A, D, K and B12
The liver is also responsible for producing 80% of the body’s __________.
cholesterol
What is the primary function of the endocrine system?
Regulate other functions; homeostasis
These are chemical messenger molecules produced by endocrine glands and then carried via the blood to their target cells.
Horomones
How does exercise affect the endocrine system in reference to O2 and CO2?
Detects that blood pressure is too low, signaled by the hypothalamus, because muscles are dilating and taking up a greater portion than normal.
Chemoreceptor detect low O2 and high CO2, low pH concentration.
Releases hormones to raise heart rate, stroke volume and vasoconstriction to help raise blood pressure and oxygen delievery.
How does exercise affect the endocrine system via the pancreas?
A portion of the pancreas will secrete glucagon and insulin to raise and lower blood sugar.
Well trained athletes are sensitive to insulin and react more than normal to store glycogen and fat in the muscle sit. (T/F)
True
Stress has little to no affect on the immune system (T/F)
False
The process of muscle contraction requires ____ and ____ which is key for relaxation or release of the cross bridge.
calcium; ATP
Small motor neurons are recruited before large ones. What is the order of recruitment regarding muscle fiber types?
red, slow (type 1)
red, fast (type 2a)
white, fast (type 2b)
Which fiber types are glycolytic fibers?
Type 2 (a,b)
Which fiber types are oxidative fibers?
Type 1 and Type 2 a
Metabolism can be broken up into two parts _____ and _____
catabolism and anabolism
What is catabolism?
breakdown of molecules for energy
What is anabolism?
synthesis of all compounds needed by the cells to repair damaged tissue
What are the two types of Carbs?
complex and simple sugars
What are two types of fiber?
Soluble and Insoluble
All-natural complex carbs are sources of ______ fiber.
soluble
If you eat too much ______ fiber you may experience ______ within 20 to 30 min after eating.
soluble; cramps
______ fiber is not digestible. How is this good?
Insoluble; it absorbs water in small intestines, passes to large intestines allowing for smooth passage of excrement.
What is an easy way to look for insoluble fiber in food?
Look for “BRAN” on food labels.
What is Hypoglycemia?
A metabolic disorder that can result from a prolonged eating behavior of consuming simple sugars.
The body’s blood sugar goes below a healthy level.
Type ____ diabetes is a metabolic disorder that can result of eating too many simple sugars for a prolonged period of time.
2
What are the principle enzymes that breakdown all carbs in the small intestine?
amylase
What are glucose polymers?
Smaller chains of glucose molecules
What does amylase break down carbs into?
simple sugars like lactose, fructose, glucose and glucose polymers
lactose, fructose, and glucose are all _______.
simple sugars
_____ is the only usable form of simple sugar in the body
glucose
The _____ releases glucose into the bloodstream to raise blood sugar levels to normal.
Liver
If blood sugar in the bloodstream is too high, what happens?
The pancreas releases insulin (hormone) to attach to excess glucose for delivery to body tissues.
What is the first stop for “insulin-carried” glucose?
muscle tissue
If receptor sites on muscles don’t readily take up glucose they are said to be ________ resulting from _______
“insulin resistant”; sedentary behavior
What happens when glucose is absorbed in muscle cell?
It is used for energy and the unused portion is converted and stored in the muscle as glycogen.
If there is excess insulin-carried glucose in the blood stream, instead of going to muscle tissue, it will go to the _____.
liver
Glycogen is stored in the liver for ____ and _______
brain function and aerobic activities
What is the brain’s only source of energy?
glucose
_____ is a hormone released from the pancreas to tell the ______ to release it’s stored glycogen. Why?
Glucagon; Liver; if there is reduced Crab intake and not enough glucose.
If all muscle, liver and bloodstream is full of insulin-carried glucose, where does it go?
It is stored in fat (adipose) cells which store blood glucose rapidly.
What is gluconeogenesis and when does it happen?
when there is breakdown of blood proteins and “cannibalism” of organ and muscle tissue for needed glucose energy; This happens if/when glucagon reaches the liver but there is no glycogen stores to be released.
Why would glucagon be released to the liver?
When not enough carbs are available.
What instances would the liver not be able to provide enough glucose to the blood?
extreme dieting or over-exertion
What is the minimum daily carb intake for a healthy adult at rest?
More than 156 grams
When gluconeogenesis (specifically using protein/amino acids for energy) takes place, it results in _____ that must be broken down by the ____ and _____
ammonia (toxin); liver and kidneys
Why does cannibalism of amino acids and muscle tissue occur during intense aerobic activity?
Glucose is depleted and energy needs are beyond the oxygen and fatty acids’ supply.
What is the process called when there is cannibalism of amino acids?
deamination
During intense resistance training only the cannibalism of ______ occurs, not amino acids , blood proteins and organ tissue.
intracellular proteins
What is a good way to avoid cannibalism of intracellular proteins during resistance training?
eating protein regularly and eat a light, easily absorbable carb 15 min before workouts.
What is the debate regarding the GI of carbs?
one is not superior over another or that a GI diet yields long term results by comparison
Why does NFPT believe GI is important?
It can help set healthy guidelines for trainers and clients new to nutritional understanding
What is GI?
Glycemic Index, how fast a carb triggers a rise in blood glucose alone on an empty stomach.
What is GL
glycemic load; how much simple sugar is being taken into bloodstream
How is GL found?
GL=[GI x (carbs - fiber grams)] ÷ 100
What are low, medium, high values for GI and GL?
GI: low 55 ; med 56-69; high 70
GL: low 10 ; med 11-19; high 20
Why is replacing more carbs with protein better for you as you age?
muscles get worse at taking up sugar and fat cells become more proficient. If insulin receptor sites become sedentary, more carbs/glucose will be stored as fat.
How does exercise encourage more glucose/energy to be used instead of stored as fat?
Keeps the receptor sites in muscles active!
What are two basic factors that contribute to high cholesterol?
heredity and overconsumption
why is cholesterol essential?
The production of hormones and for the repair of certain body tissues
what kind of cholesterol is needed when hormones are synthesized?
ldls and vldls; low density lipoproteins and very low density lipoproteins
where are hdls released from to assist in removal of excess bad ldls and vldls?
The liver
what happens in inherited cases of high cholesterol?
The liver produces too much cholesterol
what can help lower “bad” cholesterol?
diet and exercise
over consumption of what type of fats can cause high cholesterol?
saturated fats
what are fats broken down by in the small intestines?
lypolytic enzymes
what three things are fats broken down into in the small intestine?
phospholipids, triglycerides and cholesterols
what are the phospholipids, triglycerides and cholesterols packaged back into?
Fat particles called chylomicrons
chylomicrons transport fat particles from where to where?
Small intestine to the bloodstream by the way of the lymphatic system.
They are taken up by fat tissue or by the liver where they are broken back down again into the phospholids, triglycerides, LDL and VLDL cholesterols
what do phospholipids do when they are released in the blood?
structural membrane formation to different cells
what are triglycerides broken down into?
fatty acids and glycerol
what are fatty acids used for when released into the blood?
an abundant source of energy during both low-level and steady-state aerobic activity
by what system do chylomicrons enter the bloodstream?
lymphatic system
complete proteins require ingestion every ______ hours.
3 to 4
How much protein can be assimilated every 3 to 4 hours?
20 g
what happens to existing amino acids if missing amino acids are not provided within 3 to 4 hours?
they are deaminated and are no longer useful for protein synthesis
(primarily in liver but also in kidneys)
what does the liver do with amino acids and why?
It uses them to build and store catabolic enzymes for their release during times of physical stress.
It also builds blood proteins using the amino acids.
what does the liver do with amino acids if a person’s diet has insufficient carbohydrates?
It deaminates the amino acids and uses them to produce glucose energy with a toxic byproduct of ammonia
where are proteins first broken down and how?
in the stomach with the enzyme pepsin broken down into peptides
where are amino acids formed?
in the small intestine when peptides are broken down, originally from proteins broken down in the stomach
when does amino acid deamination usually occur?
strict dieting, overexertion, and/or while on a very high protein diet
who are excessive protein intake unhealthy for?
people with existing liver or kidney disease
when and why would protein catabolism take place?
starvation or under low glycogen supplies
what is the process of transamination known as?
usually when an amino group is accepted by a keto acid and then becomes an amino acid
what are two ways an amino acid may enter the metabolic processes
as either an acetyl coenzyme or a pyruvate
what are the two basic functions that amino acids are called to perform once in the muscle?
catalyst formation and protein synthesis
what constitutes overtraining?
The duration and intensity of exercise is too great. There’s insufficient amino acids and, instead, the muscle tissue itself is used for catalyst synthesis
what is anabolism?
growth and tissue repair
what is catabolism?
tissue breakdown
what three amino acids make up almost 60% of all muscle tissue and volume?
leucine, isoleucine and valine
what is catalyst formation?
The first basic function of amino acids once taken up by the muscle cells. It is the most vital function and takes precedence over tissue repair. Without catalysts the muscle fiber would no longer function.
what is protein synthesis?
repairing and building new tissue
