Introduction to metabolism Flashcards
deck complete
what substances undergo breakdown (catabolic pathways)
proteins
fats
carbohydrates
what is produced by catabolic pathways/breakdown
byproducts:
- energy (atp) - work/heat
- reducing poer (nadph)
co2
intermediates
what goes into biosynthesis (anabolic pathways)
the intermediates of breakdown
what byproducts of breakdown are required for biosynthesis
ATP and NADPH
what is produced by biosynthesis
macromolecules
what do macromolecules go into
growth
what is produced by growth
cell structures
what processes occur from glucose, fatty acids, aminoacids, ADP and Pi
glycolysis
fatty acid oxidation
aminoacid breakdown
TCAcycle and ET-chain
what is produced by the processes of glycolysis, fatty acid oxidation, aminoacid breakdown and TCAcycle and ET-chain
co2 and atp
what does ATP go into to produce ADP and Pi
muscle contraction
biosynthetic reactions
ion pumping
what is produced by ion pumping, biosynthetic reactions and muscle contractions
ADP and Pi
what is adenosine triphosphate
ATP - source of energy for use and storage at the cellular level
equation for ATP
ATP + H2O <-> ADP + Pi
what process occurs from glucose and NADP+
pentose-phosphate pathway
what is produced by the pentose phosphate pathway
CO2 and NADPH
what processes are NADPH used in
cholesterol synthesis
fatty acid synthesis
ribonucleotide reduction
what is nicotinamide-adenine dinucleotide phosphate
NADP - a biological carrier of reducing equivalents meaning it can accept and deliver electrons. it functions generally as a coenzyme
what is the oxidised form of NADP
NADP+
what is the reduced for of NADP
NADPH
what is the equation for NADP
NADP+ + 2[H] = NADPH + H+
dietary requirments
energy
macronutrients
electrolytes and minerals
vitamins
sources of energy in a typical western diet
carbohydrate
fat
protein
alcohol
enzymes in the parotid gland
⍺-amylase
enzymes in the stomach
pepsin
H+ (pH<1)
enzymes in the pancreae
⍺-amylase
TAG lipase
trypsin
chymotrypsin
elastase
carboxypeptidase A&B
phospholipases
HCO3- (pH>8)
enzymes in the small intestine
peptidases
glucoamylase
sucrase/isomaltase
lactase
enzymes in the liver/gallbladder
bile acids
bile salts
cholesterol
HCO3- (pH7.8)
carboydrates in a typical western diet
starch - polysaccharide
sucrose - disaccharide
lactose - disaccharide
glucose - monosaccharide
how much of the energy requirement does carbohydrate make up
50%
what carbs are usually unimportant
free glucose and glycogen
what are all major dietary carbs convertible to
glucose
digestion pathway of amylose (starch, 10%)
amylose > maltose > glucose
maltose > glucose via glucoamylase (small intestine)
digestion pathway of amylopectin (starch, 90%)
amylopectin > maltose > glucose
OR
amylopectin > isomaltose > glucose
amylopectin > maltose via amylase (saliva and pancreas)
isomaltose > glucose via isomaltase (small intestine)
digestion of sucrose
sucrose > glucose
OR
sucrose > fructose > glucose
sucrose > fructose via sucrase (small intestine)
digestion of lactose
lactose > galactose > glucose
lactose > galactose via lactase (β-galactosidase) (small intestine)
OR
lactose > glucose
glucose metabolism in muscle
IN CYTOPLASM
glucose
glucose-6-phosphate <-> glucose-1-phosphate <- glycogen
2 pyruvate <-> 2 lactate + 2H+
IN MITOCHONDRIA
* 2CO2
2 acetyl-CoA
4 CO2
how much energy is produced by glycolysis
2 atp
is glycolysis aerobic or anaerobic
anaerobic
how much energy is produced by the TCA cycle and oxidative phosphorylation
~ 30 atp
is the TCA cycle and oxidative phosphorylation aerobic or anaerobic
aerobic
what happens to dietary fat in the small intestine
dietary fat > TAG > MAG via pancreatic lipase
MAG + fatty acids turn back into TAG in the intestinal mucosa
what happens to TAG in the intestinal mucosa
TAG > chylomicrons
what happens to chylomicrons in the blood
chylomicrons > fatty acids via lipoprotein lipase
fatty acids then found in muscle and adipose tissue
what happens to chylomicron remnants in the blood
moved to the liver
what happens to fatty acids in adipose tissue
formed by either glucose or chylomicrons
fatty acids form TAG
TAG turns into free fatty acids in blood via hormone sensitive lipase
what happens to free fatty acids in the blood
turns into fatty acids in the muscle
what happens to fatty acids in the muscle
turns into TAG and CO2
features of chylomicrons
apolipoproteins
vitamins A, D, E A and K
cholesterol 5%
triacylglycerol + acylcholesterol 86%
phospholipid 8%
what happens to dietary protein
moves to amino acid pool
relation between amino acid pool and body protein
~ 300g/day moves from each pool to the other
what happens with amino acids in the amino acid pool
body protein
biosynthetic products
N-free intermediates
what is a byproduct of amino acids moving to N-free intermediates
NH3
what is NH3 excreted as
urea
what are N-free intermediated turned into
biosynthetic products
glucose
ketone bodies
CO2 + H2O
nitrogen balance equation
nitrogen balance = N ingested - N excreted
digested proteinases and zymogens in the stomach
pepsinogen > pepsin
digestive proteinases and zymogens in small intestine
trypsinogen > trypsin
chymotrypsinogen > chymotrypsin
proelastase > elastase
procarboxypeptidase A+B > carboxypeptidase A+B
what happens to amino acids int the tissues during protein turnover
aminoacid > carbon skeleton (ketoacid) or glutamate via transamination
what happens to carbon skeletons (ketoacids) in the tissues during protein turnover
becomes CO2 via oxidation
what happens to glutamate in the tissues during protein turnover
becomes alanine or glutamine in the blood
what happens to alanine in the blood during protein turnover
alanine > glutamate in liver
what happens to glutamate in the liver during protein turnover
glutamate > NH3 or aspartate
both NH3 and aspartate undergo urea cycle to become urea
urea passes through blood to kidneys then excreted in urine
what happens to glutamine in blood during protein turnover
2 paths
glutamine (blood) > NH3 (kidneys) > NH4+ (urine)
glutamine (blood) > glutamate (kidneys) > glucose via gluconeogenesis (kidneys then released into bloodstream)
metabolic classification of aminoacids - glucogenic
non essential: ala, asp, asn, cys, gln, glu, pro, ser
essential: met, thr, val, arg, his
metabolic classification of aminoacids - ketogenic
essential: leu, lys
metabolic classification of aminoacids - both glucogenic and ketogenic
non essential: tyr
essential: ile, phe, trp
metabolic classification of aminoacids - neither glucogenic or ketogenic
non essential: gly
energy production - from fat
fat (cytoplasm) > β-oxydation (mitochdria) > acetyl-CoA (mitochondria)
energy production - from carbohydrate
carb (cytoplasm) > glycolysis (cytoplasm) > acetyl-CoA (mitochondria)
energy production - from protein
protein (cytoplasm) > aminoacid breakdown (mitochondria) > acetyl-CoA (mitochondria)
what goes into TCA cycle
acetyle-CoA
oxidised coenzymes
what does the TCA cycle produce
byproduct of CO2
reduced coenzymes
what goes into electron transport chain
reduced coenzymes
O2
what comes out electron transport chain
oxidised coenzymes
H2O
electrochemical H+ potential
what goes into ATP synthase
electrochemical H+ potential
ADP+Pi
what does ATP synthase produce
ATP (shock)
what is carbohydrate broken down into in the gut
glucose
where does glucose travel to during metabolism
liver, muscle, adipose tissue, brain
what does glucose turn into in the liver
glycogen
what does glucose turn into in the mucle
lactate
glycogen
where does lactate from the muscle travel to
the liver
what does lactate in the liver become
glucose
what does glucose in adipose tissue become
fatty acids
what is protein broken down into in the gut
aminoacids
where do aminoacids travel from the gut
liver and muscle
what do aminoacids synthesis in the liver
glucose
what do aminoacids synthesise in the muscle
protein
what does triacylglycerol break down into in the gut
fatty acids
what do fatty acids form in the gut
triacylglycerol
where does triacylglycerol travel to from the gut
muscle and adipose tissue
what does triacylglycerol form in the muscle and adipose tissue
fatty acids
what do fatty acids form in the adipose tissue
triacylglycerol
what does glucose turn into in the brain
CO2 + H20
byproduct of ATP
