nutrition, metabolism, body temp chp 25 Flashcards
metabolism
all of bodys reactions at any given moment
all chemical reactions that take place in the body
catabolism
breakdown of organic substrates
reaction that breakdown large molecules into their smaller ones
anabolism
synthesis of new organic substrates
reactions that build larger molecules from smaller ones
how much ATP is produced in glycolysis
2 atp
how much ATP is produced in aerobic metabolism
34 atp
describe the primary function of glycolysis
- its the first step in breaking down glucose
- anaerobic process taking place in the cytoplasm
splits a 6 carbon glucose molecule into two 3 carbon molecules of pyruvate (makes 2 pyruvates to feed mitochondria with)
- 2 atp from here
describe the primary function of the citric acid cycle (TCA or krebs cycle)
to remove hydrogen atoms from organic molecules and transfer them to coenzymes and deliver them to ETS/ETC
- aerobic
- takes place in mitochondria
95% of atp is made where
in the mitochondria
describe how oxidative phosphorylation works
its the transfer of electrons and attachment of high energy phosphate group to ADP
-produces more than 90% of atp used by our body cellls
-oxygen is the final electron acceptor for oxidative of food molecules
** uses oxygen to add a phosphate molecule to adp to form atp **
the role of coenzymes (NAD + FAD)
transfers hydrogen atoms to cytochromes of ETS
(releases hydrogen ion and passes electron to next until they get to the ETC/ETS)
basically deliver hydrogen atoms from citric acid cycle to ETS
what is a cytochrome?
proteins embedded in the inner mitochondrial membrane that electrons from H atoms are passed to
how is atp produced in the ETS/ETC?
energy provded by the H ion movement back to mitochondrial matrix to eliminate the conc. gradient, activate ATP synthease = phosphorylation of adp to ATP
why are carbohydrates preferred substrates for catabolism
easy energy and function to produce energy
why is protein NOT the preferred substrate for catabolism
because its used for other cell structure or body structure and functions
chlyomicrons are
digested lipids coated with proteins which makes them water soluble and more easily transported in body fluids
-lipoproteins
lipid protein complexes with insoluble lipids (water soluble)
LDL’s /low density lipoproteins
lipids in circulation heading to cells
- bad cholesterol
HDL’s
lipids heading back to liver for recycling
- good cholesterol
lipolysis
breaks down lipid
- these broken down lipids can be converted to pyruvate or directly enter the citric acid cycle
lipogenesis
creating new lipids
what are the 2 general patterns of metabolic activity
- absorptive state
- postabsorptive state
absorptive state
first 4 hours after a meal , insulin is the dominant hormone
- absorbing nutrients here
- high glucose levels
- insulin stimulates glucose uptake
- triglyceride synthesis
postabsorptive state
after 4 hours post meal, glucagon is dominant hormone
- no nutrient absorption
- body relies on energy reserves
- low blood pressure glucose levels
- mobilization of energy reserves
- maintains blood glucose levels at 70-110mg/100mL
- other hormones such as epinephrine , glucocorticoids, GH
what are vitamins
organic compounds that play essential roles in several metabolic pathways
- act as coenzymes to assist enzyme functions
- 2 categories (water and fat soluble ones)
fat soluble enzymes are
A, D, E, K
- absorbed from digestive tract with lipid content of micelles
- involved in hypervitaminosis since they are not easily eliminated in urine
