Chapter 26: Nutrition and Metabolism
ghrelin
-hunger-arousing hormone secreted by an empty stomach -stimulates the hypothalamus to secrete growth hormone -hormone primes the body to take best advantage of the nutrients about to be absorbed -ceases within an hour of eating
oxidation of a typical fatty acid can yield ___ ATP
129
what are the 4 end products of glycolysis?
2 pyruvic acid + 2 NADH + (2H+) + 2 ATP
type I alcoholism usually sets in after age ____ and is associated with
25; peer pressure
fats should makeup ____% of the daily caloric intake
30%
How many ATP does glycolysis and aerobic respiration produce versus anaerobic fermentation?
38;2
the absorptive state lasts about _____ hours during and after a meal.
4 hours
fats yield ___ kcal/g; carbs and proteins yield ____ kcal/g
9;4
leptin
A chemical produced by the adipose cells that seems to signal that plenty of fat is stored and that no more fat is needed; this signal may diminish eating.
beta oxidation
A metabolic sequence that breaks fatty acids down to two-carbon fragments which enter the Krebs cycle as acetyl CoA.
acidosis
A pathologic condition resulting from the accumulation of acids in the body; can be fatal
shivering warms the body by ______________
ATP hydrolysis
NADH
An energy-carrying coenzyme produced by glycolysis and the Krebs cycle. NADH carries energy to the electron transport chain, where it is stored in ATP.
what is the overall chemical reaction equation for aerobic respiration?
C6H12O6 + 6 O2 = 6 CO2 + 6 H2O
urea is a nitrogenous waste made from _____ and ______________
CO 2 and ammonia
describe basic process of short-term appetite regulation
Figure 26.1
Bonus: see if you can "freestyle" describe the basic lipoproteins pathway
Figure 26.2 B
list the 3 *short-term* gut-brain peptides
Ghrelin, peptide YY, Cholecystokinin
chemiosmotic mechanism
H+ flow rushing through mitochondiral membrane providing energy for ATP synthesis- flow is from high proton concentration to low
insulin
Hormone produced by the pancreas that is released when stimulated by elevated glucose levels. This hormone decreases blood sugar levels by accelerating the transport of glucose into the body cells where it is oxidized for energy or converted to glycogen or fat for storage.
triglycerides
Large fat molecules composed of three parts fatty acid and one part glycerol; how most fat is stored
list the 2 *long-term* gut-brain peptides
Leptin and Insulin
________ is a three-sugar carbon that can be converted to glycerol.
PGAL (phosphoglyceroldehyde)
anaerobic fermentation
The metabolic pathway by which pyruvic acid (a byproduct of glycolysis) is converted to lactic acid; happens when there is no oxygen; less efficient.
deamination
The removal of an amino group (-NH2) from an amino acid or other organic compound.
what is glycolysis?
a metabolic process that breaks down carbohydrates and sugars through a series of reactions to either pyruvic acid or lactic acid and release energy for the body in the form of ATP http://www.johnkyrk.com/glycolysis.html
complete proteins contain what?
all of the essential amino acids
glucagon
antagonist of insulin; release is stimulated by low blood glucose levels; stimulates the liver to break down its glycogen stores to glucose and release to the blood
What is a big biproduct of aerobic respiration?
carbon dioxide
membrane reactions
carried out in a series of reactions called the electron-transport-chain occurs in the inner membrane of the double membrane mitochondria Creates most ATP, 38 ATP per glucose!
cutaneous vasodilation
constriction or expansion of blood vessels to allow for heat retention or heat release
insulin glycogenolysis
conversion of glycogen to glucose when blood sugar is low
list functions of liver
convert ammonia to urea carry out beta oxidation synthesize cholesterol synthesize glucose from fats and amino acids
the quickest physiological means of heat loss is by ___________________________
cutaneous vasodilation
Where in the cell does glycolysis happen?
cytoplasm
to use an amino acid as fuel it must be ____________
deaminated
heat cramps are muscle spasms due to ________________________ from sweating
electrolyte imbalance
excess glucose can become ______
fat
epinephrine
fight-or-flight neurotransmitter; increases the conversion of glycogen to glucose in liver and muscle tissue in anticipation of stress; causes rise in blood glucose levels and an increase in the basal metabolic rate
___________ is also secreted by the ___________ and regulates the *postabsorptive* state
glucagon; pancreas
_____________ is the primary fuel during the absorptive state
glucose
during the postabsorptive state, glucagon promotes ____________ and ____________ to raise the blood glucose and free fatty acid levels
glycogenolysis; lipolysis
pyruvic acid is a product of what process?
glycolysis
What 2 different pathways can happen after glycolysis?
glycolysis --> (oxygen *not* available) --> anaerobic fermentation/lactic acid reduction OR glycolysis --> (oxygen available) --> aerobic respiration --> matrix reactions/Krebs --> membrane reactions/mitochondrial electron-transport chain
type II alcoholism is partially _______________
hereditary
cholecystokinin
hormone the small intestine (duodenum and jejunum) secretes to stimulate release of pancreatic juice from pancreas and bile from gallbladder
what are gut-brain peptides?
hormones that act as chemical signals from the gastrointestinal tract to the brain
adipocytes grow in adulthood by _______________
hypertrophy
___________is secreted by the __________ and regulates the absorptive state
insulin; pancreas
most tissue-protein turnover happens in the ______________
intestine
cirrhosis
irreversible disease characterized by degeneration of liver tissue, most often caused by alcoholism or a nutritional deficiency
What are chylomicrons?
made in the small intestinal cells; transport dietary lipids through the bloodstream to the liver
Factors that can lower metabolism include starvation and __________
mental state (apathy, depression)
most of the stored carbohydrate, glycogen, is found in ________ tissue
muscular
peptide YY
neuropeptide secreted in the small bowel (ileum) and colon; signals satiety (end of meal)
sugars function as the following 5 structural components:
nucleic acids glycoproteins ATP GTP cAMP
macronutrients
nutrients required in large amounts; carbohydrates, proteins, fats (lipids), water
What element/molecule is the final electron acceptor in aerobic respiration?
oxygen
ATP hydrolysis
process in which ATP is broken down and energy is harnessed
ATP synthase
protein structure in cell mitochondria that uses energy from H+ ions to convert ADP to ATP
at 70 F you lose most of your heat by _________
radiation
matrix reactions
reactions whose controlling enzymes are in the fluid of the mitochondrial matrix first principal group of reactions in aerobic respirations co2 released here primary source of co2 in breath largest part of matrix reactions is Krebs/citric acid cycle/tricarboxylic acid (TCA) cycle* (*before the Krebs Cycle begins, 2 pyruvate get converted into 2 acetyl-CoA with the help of Coenzyme A; 2 NADH & 2CO2 is produced)
what's the difference between short-term vs long-term gut-brain peptides?
short-term: act over a period of minutes to hours, managing hunger & satiety signals long-term: act over period of weeks to years, regulating body weight and metabolism
8 functions of lipids
store energy, insulation and cushioning for vital organs, vitamins, pigments, growth hormones, regulators, structural component of phospholipid bilayer in cell membranes, coat axons in brain (mylein)
glycogenesis
the conversion of glucose to glycogen when the glucose in the blood exceeds the demand
Where are low-density lipoproteins (LDLs) and high-density lipoprotens (HDLs) produced?
the liver (technically VLDLs -- Very Low-Density Lipoproteins -- are produced in the liver and then *converted* to LDLs later; HDLs just straight-up produced in the liver)
aerobic respiration
the process in which pyruvic acid is broken down and NADH is used to make a large amount of ATP
ketone bodies
the product of the incomplete breakdown of fat when glucose is not available in the cells; can cause acidosis
metabolism
the sum of all chemical processes that occur in an organism
lipogenesis
the synthesis of fat from other types of molecules
gluconeogenesis
the synthesis of glucose from noncarbs
starvation will lower your ___________________
total metabolic rate
what are the two categories of micronutirents?
vitamins and minerals
What kind of ratio of HDL to LDL is good for the body?
you would want a ratio of high HDL to low LDL