August 23- Metabolism Review BIOCHEM!! NOT HISTO Flashcards
what is an amphibolic pathway
pathway that involves catabolism and anabolism
there are 3 steps in the glycolytic pathway. what are the enzymes involved in each step in order
hexokinase, phosphofructokinase, pyruvate kinase
what is the main substrate and products of the glycolytic pathway
substrate: glucose
product: 2 ATP and 2 NADH
the conversion of glucose to glucose-6-phosphate (in the glycolytic pathway) is catalyzed by which two enzymes
hexokinase and glucokinase
what does hexokinase do
it phosphorylates hexoses
under what conditions does hexokinase operate under
normal concetrations of glucsoe
what does glucokinase do
it phosphorylates glucose
under what conditions does glucokinase operate
high concentrations of glucose
what does phosphofructokinase do
converts fructose 6 phosphate into fructose 1,6 diphosphate
what is hexokinase inhibited by
its product
what is phosphofructokinase inhibited by
high concentrations of ATP, citrate and long chain fatty acids
what is phosphofructokinase stimulated by
high concentrations of ADP or AMP
what does pyruvate kinase do
the conversion of phosphoenolpyruvate to pyruvate
what happens to the other steps when one step in the glycolytic pathway is inhibited
they are all inhibited
what is an alternative to glycolysis
the pentose phosphate pathway
where does glycolysis occur
cytoplasm of cells
what are the key enzymes in the pentose phosphate pathway
glucose 6P DH, transketolase, transaldolase, transketolase
what is the substrate and products of the pentose phosphate pathway
substrate: glucose 6P
product: NADPH, ribose, and other intermediate molecules used in the TCA cycle
where does the pentose phosphate pathway occur
in the cytosol especially in the liver, and adipose
what is pentose phosphate pathway controlled by
glucose-6-phosphate-dehydrogenase
what is pentose phosphate pathway inhibited by
high levels of NADPH and fatty acid intermediates
what forms is glucose stored in
glycogen, starch, sucrose
where does gluconeogenesis occur
in the liver or the kidneys
what is gluconeogenesis
synthesis of glucsoe from noncarbohydrate precursors
what are the substrates for gluconeogenesis
amino acids, lactic acid, glycerol
does gluconeogenesis use atp
yes
what is glycogenesis
synthesis of glycogen from glucose
where does glycogenesis occur
the liver
what is glycogenolysis
breakdown of glycogen into glucose and glucose-1- phosphate
where does glycogenolysis occur
the liver
what is the substrate and products of the krebs cycle
substrate: acetyl coA
product: 8 NADH, 2 FADH2, 2 ATP
where does the krebs cycle occur
matrix of mitochondria
Where is the ETC located
inner mitochondrial membrane
what are the substrates and products of the ETC
substrates: NADH, FADH2, O2 and ADP
products: water, CO2 and ATP
what is respiration
aerobic cells obtain energy via oxidation of fuels by oxygen
what are the 3 stages of respiration
- formation of acetyl co A from pyruvate
- Krebs cycle yields CO2 and H atoms
- ETC
What complexes does NADH work with in the ETC
1
what complex does FADH2 work with in ETC
2
what complexes are protons pumped through in the ETC
1,3,4
how many molecules of ATP does NADH yield
3
how many molecules of ATP does FADH2 yield
2
how many molecules of ATP can one molecule of glucose generate
30-32
how many molecules of ATP can fatty acid beta oxidation of palmitate yield
129
how are fatty acids transported in the serum
albumin
what is the main storage form of fatty acids
triglycerides
how are blood triglycerides transported
chylormicrons and VLDL
where are chylomicrons formed and what do they do
formed in the small intestine and transport mainly triglycerides, phospholipids, cholesterol, and proteins from the diet into the bloodstream
where is VLDL made and what does it do
made by the liver and transports endogenous triglycerides, phospholipids, cholesterol, and cholesterol esters
what configuration are most unsaturated fatty acids found in
cis fatty acids
do cis or trans unsaturated fatty acids pack closer
trans
what is Beta oxidation of fatty acids
catabolic pathway that cells use to breakdwon fatty acids into acetyl- co A to enter krebs cycle
where does beta oxidation occur
activation occurs in cytoplasm but oxidation takes place in mitochondria
how do fatty acids under beta oxidation enter the mitochondria
a carnitine transport system
does beta oxidation require ATP
yes`
explain the carnitine transport pathway in beta oxidation
activated fatty acid diffuses across outer mitochondrial membrane but has to be transported across inner membrane. once trasnported it converts into acetyl co A
what is amino acid oxidation
process by which amino acids are converted into end products that are utilized by other metabolic pathways
where does amino acid oxidation occur
liver
what is the urea cycel
metabolic pathway for detoxyfying excess nitrogen in the form of ammonia by converting it into uric acid or urea
where does the urea cycle occur
liver
what are the substrates and products of urea cycle
substrate: ammonia
prodcut: uric acid or urea
